WO2015152179A1

WO2015152179A1 - Method for preparing transformed micoorganisms and method for producing catechol compound using transformed microorganisms prepared by said method

Info

Publication number: WO2015152179A1
Application number: PCT/JP2015/060004
Authority: WO
Inventors: 大祐立岩
Original assignee: 株式会社日本触媒
Priority date: 2014-03-31
Filing date: 2015-03-30
Publication date: 2015-10-08
Also published as: JPWO2015152179A1; JP6322862B2

Abstract

[Problem to be solved] To provide a method for preparing transformed microorganisms that efficiently synthesize a catechol compound, the transformed microorganisms having an aromatic ring dioxygenase gene cluster and an aromatic ring dihydrodiol dehydrogenase gene introduced thereinto. [Solution] The problem is solved by culturing transformed microorganisms having an aromatic ring dioxygenase gene cluster and an aromatic ring dihydrodiol dehydrogenase gene introduced thereinto in liquid containing 5-100 μM of isopropyl β-thiogalactopyranoside.

Description

Method for preparing transformed microorganism, and method for producing catechol compound using transformed microorganism prepared by the method

The present invention relates to a method for preparing a transformed microorganism into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene are introduced, and a method for producing a catechol compound using the transformed microorganism prepared by the method. Furthermore, the present invention also relates to a composition having excellent stability containing a catechol compound and the use of the composition.

Catechol compounds are used as intermediates and raw materials for various industrial products such as pharmaceutical intermediates, cosmetics, antioxidants, ultraviolet absorbers, adhesives and the like. For example, catechol compounds such as hydroxytyrosol (2- (3,4-dihydroxy) phenylethanol) contained in olive extract have a high antioxidant effect, a reduced risk of coronary heart disease, melanin It is known to have various physiological functions such as synthetic inhibitory action, antibacterial / antiviral action, and other applications, and is expected to be applied to pharmaceuticals and cosmetics.

As a method for synthesizing a catechol compound, a biotechnological synthesis method using an aromatic ring dioxygenase such as toluene dioxygenase and an aromatic ring dihydrodiol dehydrogenase such as cis-toluene dihydrodiol dehydrogenase is known.

Microorganisms such as Pseudomonas putida metabolize toluene with enzymes such as toluene dioxygenase and cis-toluene dihydrodiol dehydrogenase. However, in toluene-utilizing microorganisms such as Pseudomonas putida, catechol compounds such as 3-methylcatechol are generally metabolic intermediates. For example, in Pseudomonas putida F1 strain, the generated 3-methylcatechol is degraded by 3-methylcatechol 2,3-dioxygenase (todE) (Non-patent Document 1). Therefore, when a catechol compound is produced biotechnologically using an aromatic ring dioxygenase such as toluene dioxygenase and an aromatic ring dihydrodiol dehydrogenase such as cis-toluene dihydrodiol dehydrogenase, 3-methylcatechol 2,3-di- A system in which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene are introduced into a host having a microorganism having no catechol compound metabolic activity such as oxygenase (todE) or having a low catechol compound metabolic activity, for example, Escherichia coli, etc. Used. In a system in which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase are introduced as a foreign gene, an aromatic ring dioxygen is expressed by an expression inducer such as isopropyl β-thiogalactopyranoside (hereinafter also referred to as “IPTG”). A system capable of inducing protein expression of oxygenases and aromatic ring dihydrodiol dehydrogenases can be made.

Non-Patent Document 1 discloses that a toluene dioxygenase gene group (todC1, todC2, todB, and todA) derived from Pseudomonas putida F1 strain and Escherichia coli into which cis-toluene dihydrodiol dehydrogenase gene (todD) was introduced were used. An example of synthesizing 3-toluene dihydrodiol and 3-methylcatechol from cis-toluene dihydrodiol is disclosed.

Although a method for synthesizing a catechol compound biotechnologically using a transformed microorganism into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene have been introduced is known, the efficiency of conventional known methods is low, It could not withstand typical production. Further, since the catechol compound has low stability, there is a problem that it is easily colored over time.

Accordingly, the present invention has been made in view of the above problems, and provides a method for preparing a transformed microorganism that efficiently synthesizes a catechol compound into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene have been introduced. This is the issue. Moreover, this invention makes it a subject to provide the efficient manufacturing method of a catechol compound using the transformed microorganisms prepared by this method.

Furthermore, another object of the present invention is to provide a catechol compound-containing composition having excellent stability.

As a result of diligent research, the present inventor obtained transformed microorganisms into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene had been introduced into a liquid containing isopropyl β-thiogalactopyranoside at a predetermined concentration (hereinafter referred to as the following). , Also referred to as “IPTG-containing solution”), and found that the above problems can be solved, and the present invention has been completed. The first aspect of the present invention is to prepare a transformed microorganism comprising culturing a transformed microorganism into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene have been introduced in a solution containing 5 to 100 μM IPTG. Regarding the method.

The second aspect of the present invention is the following general formula (1) using a transformed microorganism prepared by the method for preparing a transformed microorganism according to the present invention:

In the general formula (1), R is a hydrogen atom, a halogen atom, a phenyl group, a heterocyclic group, or a group represented by the following general formula (2):

In the general formula (2), x is 0 or 1, Y is a linear or branched alkylene group having 1 to 5 carbon atoms, and Z is a hydrogen atom or a hydroxyl group;
It relates to the manufacturing method of the catechol compound represented by these.

The third aspect of the present invention is the following general formula (1):

In the general formula (2), x is 0 or 1, Y is a linear or branched alkylene group having 1 to 5 carbon atoms, and Z is a hydrogen atom or a hydroxyl group;
And a catechol compound represented by the following general formula (3):

In the general formula (3), R ′ is a hydrogen atom, a halogen atom, a phenyl group, a heterocyclic group, or a group represented by the following general formula (4):

In the general formula (4), x ′ is 0 or 1, Y ′ is a linear or branched alkylene group having 1 to 5 carbon atoms, and Z ′ is a hydrogen atom or a hydroxyl group. And a ratio of the monohydroxide to 100 mol of the catechol compound is 0.002 to 5 mol.

FIG. 1 shows a TIC chromatogram when the reaction was carried out using 2-phenylethanol as a substrate. FIG. 2 shows the mass spectrum for the peak with a retention time of 13.7 minutes in the chromatogram of FIG. FIG. 3 shows a TIC chromatogram when the reaction was carried out using 2-phenoxyethanol as a substrate. FIG. 4 shows the mass spectrum for the peak with a retention time of 13.9 minutes in the chromatogram of FIG. FIG. 5 is a graph showing the pH of the culture solution in Example 4. Dissolved oxygen concentration (DO) and OD ₆₆₀ values 6 is a graph showing the dissolved oxygen concentration (DO) of the culture solution in Example 4. FIG. FIG. 7 is a graph showing the OD ₆₆₀ value of the culture solution in Example 4. FIG. 8 schematically shows the structure of the cassette (1) and the cassette (2). FIG. 9 schematically shows a cassette in the recombinant plasmid introduced into the transformed strain in Example 6. FIG. 10 is a graph showing the dissolved oxygen concentration (DO) of the culture solution in Example 6. FIG. 11 is a graph showing consumption of the aromatic compound raw material (2-phenylethanol) in the reaction solution in Example 6. FIG. 12 is a graph showing the amount of catechol compound (2- (2,3-dihydroxyphenyl) ethanol) produced in the reaction solution in Example 6. FIG. 13 is a graph showing the selectivity of a catechol compound (2- (2,3-dihydroxyphenyl) ethanol) in Example 6. FIG. 14 shows the results of measuring the UV-VIS spectrum of a sample before storage in a test for evaluating the effect of monohydroxide on the stability of a catechol compound. FIG. 15 is a result of measuring a UV-VIS spectrum of a sample after storage at 60 ° C. for 4 days in a test for evaluating the effect of the monohydroxide on the stability of the catechol compound. FIG. 16 is a graph showing the effect of the composition according to the present invention as a whitening agent. FIG. 17 is a graph showing the effect of the composition according to the present invention as an oxygen absorbent. FIG. 18 is a graph showing the effect of the composition according to the present invention as an oxygen absorbent.

Hereinafter, embodiments of the present invention will be described. In addition, this invention is not limited only to the following embodiment. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios.

In the present specification, “X to Y” indicating a range means “X or more and Y or less”, “weight” and “mass”, “weight%” and “mass%”, “part by weight” and “weight part”. “Part by mass” is treated as a synonym. Unless otherwise specified, measurement of operation and physical properties is performed under conditions of room temperature (20 to 25 ° C.) / Relative humidity 40 to 50%.

The first aspect of the present invention is to prepare a transformed microorganism comprising culturing a transformed microorganism into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene have been introduced in a solution containing 5 to 100 μM IPTG. Regarding the method. According to the first aspect of the present invention, there is provided a method for preparing a transformed microorganism for efficiently synthesizing a catechol compound, into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene are introduced. One embodiment of the present invention is a method for preparing a transformed microorganism, comprising culturing a transformed microorganism into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene have been introduced in a solution containing 5 to 30 μM IPTG. About.

The following reaction formula (1) shows an aromatic compound raw material (hereinafter referred to as an aromatic compound raw material used for the production of a catechol compound) catalyzed by an aromatic ring dioxygenase and an aromatic ring dihydrodiol dehydrogenase. It represents a reaction in which a catechol compound is produced from a “substrate”. In the following reaction formula (1), R is the same as in the general formula (1). Aromatic ring dioxygenases such as toluene dioxygenase add one hydroxyl group to two adjacent carbon atoms in the aromatic ring of an aromatic compound such as toluene, benzene, naphthalene, and biphenyl. From an aromatic compound to which a hydroxyl group has been added by an aromatic ring dioxygenase (hereinafter, an “aromatic compound to which a hydroxyl group has been added by an aromatic ring dioxygenase” is also simply referred to as a “dihydrodiol derivative”), cis-toluene dihydrodiol A hydrogen atom is extracted by an aromatic ring dihydrodiol dehydrogenase such as dehydrogenase to synthesize a catechol compound.

[Transformed microorganism]
The transformed microorganism used in the present invention is produced by introducing an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene into a host microorganism.

An aromatic ring dioxygenase is composed of four subunits consisting of a large subunit, a small subunit, ferredoxin, and a ferredoxin reductase, and introduces an oxygen atom derived from an oxygen molecule (O ₂ ) into the aromatic ring as a hydroxyl group. (The first half reaction in the reaction formula (1)). In the present specification, genes encoding the large subunit, small subunit, ferredoxin, and ferredoxin reductase of aromatic ring dioxygenase are collectively referred to as “aromatic ring dioxygenase gene group”. In the aromatic ring dioxygenase, four subunits are conjugated, and one hydroxyl group is added to two adjacent carbon atoms in the aromatic ring of an aromatic compound such as benzene. The aromatic ring dioxygenase is particularly suitable as long as it catalyzes a reaction for introducing an oxygen atom derived from an oxygen molecule (O ₂ ) into the aromatic ring as a hydroxyl group (for example, those classified as EC 1.14.12.-). Not limited. More specifically, examples of the aromatic ring dioxygenase that can be used in the present invention include toluene dioxygenase classified as EC 1.14.12.11, and benzene- classified as EC 1.14.12.3. 1,2-dioxygenase, biphenyl-2,3-dioxygenase classified as EC 1.14.1.12.18, carbazole-1,9a-dioxygenase classified as EC 1.14.12.22, EC Examples include terephthalic acid-1,2-dioxygenase classified into 1.14.12.15, benzoyl CoA-2,3-dioxygenase classified into EC 1.14.12.21, and the like. In addition to these aromatic ring dioxygenases, the reaction described in the above reaction formula (1) can be catalyzed by adding one hydroxyl group to two adjacent carbon atoms in the aromatic ring of the aromatic compound. Aromatic ring dioxygenases are also included in the present invention.

When toluene is used as a substrate, toluene dioxygenase is known to catalyze a chemical reaction represented by the following reaction formula (2). In the present invention, an aromatic ring dioxygenase gene group encoding an aromatic ring dioxygenase that catalyzes the reaction represented by the following reaction formula (2) is preferably used.

Among these aromatic ring dioxygenases, in the present invention, toluene dioxygenase or benzene-1,2-dioxygenase (that is, toluene dioxygenase gene group or benzene-1,2-dioxygenase gene group) is more preferable, More preferred is toluene dioxygenase. That is, in one embodiment of the present invention, a method for preparing a transformed microorganism in which the aromatic ring dioxygenase gene group is a toluene dioxygenase gene group is provided. In addition to toluene, toluene dioxygenase uses benzene, halogenated benzene, ethylbenzene, xylene, phenyl alcohol (for example, 2-phenylethanol) or the like as a substrate. The present inventor has also found that toluene dioxygenase uses phenoxy alcohol (for example, 2-phenoxyethanol) as a substrate.

The organism from which the aromatic ring dioxygenase (aromatic ring dioxygenase gene group) is derived is also not particularly limited. Many bacteria are known to express aromatic ring dioxygenase, for example, Pseudomonas putida (eg, P. putida F1 strain (ATCC 700007), P. putida T-12 strain, P. putida IH-2000). Strains, P. putida DOT-T1E strain, or P. putida T-57 strain), P. aeruginosa, P. pseudoalcigenes (for example, P. pseudoaligenes F. strain 70) Toluene dioxygens derived from the genus Pseudomonas such as SP (P.sp.) (for example, P.sp. NCIB 9816-4 strain) In addition to Bose, the genus Burkholderia (for example, B. cepacia LB400), Bordetella (for example, B. sp. IITR02), Sphingomonas (genus), Rhizobium (genus Rhizobium) (For example, R. sp. TSY03b strain), Rhodococcus genus (for example, R. jostii RHA1 strain), Janibacter genus (for example, J. sp. TYM3221 strain), Aspergillus genus (for example, , A. kawachii IFO 4308 strain), Ralstonia genus (for example, R. sp. JS705 strain), etc. It may be. These microorganisms can be obtained from ATCC, NBRC, and the like.

Among them, Pseudomonas aromatic ring dioxygenase (especially toluene dioxygenase; that is, a toluene dioxygenase gene group derived from Pseudomonas genus) is preferable because of its high activity, and Pseudomonas putida (that is, Pseudomonas putida) (Toluene dioxygenase gene group) is more preferable. SEQ ID NOs: 1 to 4 show the amino acid sequences of the large subunit, small subunit, ferredoxin, and ferredoxin reductase of toluene dioxygenase derived from Pseudomonas putida F1 strain.

In the present invention, in amino acid sequences 1 to 4, it consists of an amino acid sequence in which one or several amino acids are deleted, substituted or added, and an oxygen atom derived from an oxygen molecule (O ₂ ) is used as a hydroxyl group in an aromatic ring. A gene encoding an enzyme having an activity of catalyzing the reaction to be introduced is also preferably used. Here, “several” is usually 2 to 5, preferably 2 to 3. Examples of conservative substitutions between different amino acid residues include glycine (Gly) and alanine (Ala); valine (Val), leucine (Leu) and isoleucine (Ile); glutamic acid (Glu) and aspartic acid (Asp); Substitutions between amino acids such as glutamine (Gln) and asparagine (Asn); threonine (Thr) and serine (Ser); or lysine (Lys) and arginine (Arg) are known.

The aromatic ring dihydrodiol dehydrogenase catalyzes a reaction of oxidizing a dihydrodiol derivative of an aromatic compound to a catechol compound (the latter reaction in the reaction formula (1)). More specifically, examples of the aromatic ring dihydrodiol dehydrogenase that can be used in the present invention include cis-toluene dihydrodiol dehydrogenase, cis-benzene dihydrodiol dehydrogenase classified in EC 1.3.1.19, EC 1. 3.1 cis-2,3-dihydrobiphenyl-2,3-diol dehydrogenase classified as 1.56, cis-1,2-dihydro-1,2-dihydroxy classified as EC 1.3.1.29 Naphthalene dehydrogenase, phthalate-4,5-cis-dihydrodiol dehydrogenase classified as EC 1.3.1.64, cis-1,2-dihydroethylcatechol dehydrogenase classified as EC 1.3.1.66 Etc.

Cis-Toluene dihydrodiol dehydrogenase catalyzes a chemical reaction represented by the following reaction formula (3) classified in EC 1.3.1.19. In the present invention, an aromatic ring dihydrodiol dehydrogenase gene encoding an aromatic ring dihydrodiol dehydrogenase that catalyzes a reaction represented by the following reaction formula (3) is preferably used.

Of the above aromatic ring dihydrodiol dehydrogenases, cis-toluene dihydrodiol dehydrogenase is more preferred in the present invention. That is, in one embodiment of the present invention, a method for preparing a transformed microorganism in which the aromatic ring dihydrodiol dehydrogenase gene is a cis-toluene dihydrodiol dehydrogenase gene is provided. In addition to cis-toluene dihydrodiol dehydrogenase, metabolites (dihydrodiol derivatives) of aromatic ring dioxygenase such as benzene, halogenated benzene, ethylbenzene, xylene, or phenyl alcohol (for example, 2-phenylethanol), in addition to cis-toluene dihydrodiol ) As a substrate, and a reaction according to the reaction formula (3) is catalyzed. The present inventor has also found that cis-toluene dihydrodiol dehydrogenase uses a metabolite (dihydrodiol derivative) of phenoxy alcohol (for example, 2-phenoxyethanol) by aromatic ring dioxygenase as a substrate.

The organism from which the aromatic ring dihydrodiol dehydrogenase (aromatic ring dihydrodiol dehydrogenase gene) is derived is not particularly limited. For example, the above-mentioned bacteria exemplified as those expressing aromatic ring dioxygenase can be mentioned. The organism from which the aromatic ring dioxygenase gene is derived and the organism from which the aromatic ring dihydrodiol dehydrogenase gene is derived may be the same or different, but are preferably the same.

Among these, Pseudomonas aromatic ring dihydrodiol dehydrogenase (in particular, cis-toluene dihydrodiol dehydrogenase; that is, cis-toluene dihydrodiol dehydrogenase gene derived from Pseudomonas) is preferable, and Pseudomonas putida (ie More preferred is a cis-toluene dihydrodiol dehydrogenase gene derived from Pseudomonas putida. SEQ ID NO: 5 shows the amino acid sequence of cis-toluene dihydrodiol dehydrogenase derived from Pseudomonas putida F1 strain.

In the present invention, the amino acid sequence 5 has an amino acid sequence in which one or several amino acids are deleted, substituted or added, and has an activity of catalyzing a reaction of oxidizing a dihydrodiol derivative of an aromatic compound to a catechol compound. A gene encoding the enzyme is also preferably used. Here, “several” is usually 1 to 10, preferably 2 to 8.

The transformed microorganism used in the preparation method according to the present invention comprises a gene encoding the above aromatic ring dioxygenase and aromatic ring dihydrodiol dehydrogenase or a part thereof linked to an appropriate vector, and the obtained recombinant vector. It can be prepared by introducing the gene of interest into a host so that the gene of interest can be expressed, or by inserting the gene of interest or a part thereof at any position on the genome by homologous recombination. “Part” refers to a part of each gene capable of expressing the protein encoded by each gene when introduced into a host. In the present invention, the gene includes DNA and RNA, preferably DNA.

The method of obtaining a desired gene from the genome of a microorganism by cloning is well known in the field of molecular biology. For example, when the gene sequence is known, a suitable genomic library can be prepared by restriction endonuclease digestion and screened using a probe complementary to the desired gene sequence. Once the sequence is isolated, the DNA is amplified using standard amplification techniques such as the polymerase chain reaction (PCR) (US Pat. No. 4,683,202), and an appropriate amount of DNA is transformed. Obtainable. The aromatic ring dioxygenase gene group and the aromatic ring dihydrodiol dehydrogenase gene are obtained by a hybridization method, a PCR method, etc. using a synthetic primer appropriately designed based on the base sequence of the known gene in addition to the known gene. You can also

Methods for preparation of genomic DNA library used for gene cloning, hybridization, PCR, plasmid preparation, DNA cleavage and ligation, transformation, etc. are described in Sambrook, J et al. , Molecular Cloning 2nd ed. , 9.47-9.58, Cold Spring Harbor Lab. Press (1989).

The vector for linking genes is not particularly limited as long as it can be replicated in the host, such as plasmids, phages, cosmids, etc., used for introducing foreign genes, but preferably has a promoter capable of inducing expression by IPTG. Used. That is, in one embodiment of the present invention, a transformed microorganism into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene incorporated downstream of a promoter capable of inducing expression by IPTG is used. Examples of the promoter sequence capable of inducing expression by IPTG include T7 promoter, lac promoter, tac promoter, trc promoter, spac promoter and the like. Among these, from the viewpoint of high promoter activity (frequency of transcription), T7 promoter or tac promoter is preferably used, and T7 promoter is more preferably used. More specifically, vectors for linking genes include pET (manufactured by Novagen), pGEX (manufactured by GE Healthcare), pHAT20, pTV118N (manufactured by Takara Bio Inc.), pMAL (manufactured by New England Biolabs). , PQE (Qiagen), pMUTIN (Vagner V., et. Al. Microbiology (1998), 144, 3097-3104), pHT (MoBiTec), pCDFDuet-1 (Novagen), pUC18 (Takara Bio) In addition to plasmids having T7 promoter, T5 promoter, lac promoter, tac promoter, trc promoter, lpp promoter or spac promoter, such as λgt10, M13mp18, Phage such as 13mp19 and the like. The aromatic ring dioxygenase gene group and the aromatic ring dihydrodiol dehydrogenase gene may be linked to a single vector, or may be linked to separate vectors.

Gene sequences encoding large subunit (todC1), small subunit (todC2), ferredoxin (todB), and ferredoxin reductase (todA) of Pseudomonas putida F1 toluene dioxygenase in SEQ ID NOs: 6 to 9, In addition, SEQ ID NO: 10 exemplifies a gene sequence encoding cis-toluene dihydrodiol dehydrogenase (todD) of Pseudomonas putida F1 strain.

Here, the large subunit of the aromatic ring dioxygenase gene group, the small subunit, ferredoxin, and the gene encoding ferredoxin reductase (that is, aromatic ring dioxygenase gene group), and aromatic ring dihydrodiol dehydrogenase gene, respectively, A gene functionally equivalent to the gene consisting of the nucleotide sequence represented by SEQ ID NOs: 6, 7, 8, 9, and 10 is also preferably used. “Functionally equivalent gene” means that the protein encoded by the target gene has the same biological function and biochemical properties as the protein encoded by the gene consisting of the base sequence represented by each SEQ ID NO. It means having a function.

As a method well known to those skilled in the art for preparing a gene encoding a protein functionally equivalent to a certain protein, a method using a hybridization technique can be mentioned.

For example, in the full length of the base sequence represented by SEQ ID NO: 6, various artificial treatments such as site-directed mutagenesis, random mutation by treatment with a mutagen, mutation of nucleic acid fragments by restriction enzyme cleavage, deletion, ligation, etc. Even if the sequence is partially changed, these mutant genes hybridize under stringent conditions with a gene consisting of a base sequence complementary to the base sequence represented by SEQ ID NO: 6, As long as the large subunit activity of the aromatic ring dioxygenase, i.e., the small subunit of the aromatic ring dioxygenase, ferredoxin, and a protein that exhibits the activity of the aromatic dioxygenase together with ferredoxin reductase, it encodes the aromatic ring dioxygenase. It can be used as a gene encoding the large subunit of oxygenase. The same applies to genes encoding other subunits and genes encoding aromatic ring dihydrodiol dehydrogenase.

Stringent conditions refer to conditions in which specific hybrids are formed and non-specific hybrids are not formed, that is, conditions in which DNA having high homology to each gene hybridizes. More specifically, such conditions include hybridization at 42-68 ° C. in the presence of 0.5-1 M NaCl, or 42 ° C. in the presence of 50% formamide, or 65-68 ° C. in aqueous solution. Thereafter, the membrane can be washed at room temperature (25 ° C.) to 68 ° C. using a SSC (saline sodium citrate) solution having a concentration of 0.1 to 2 times.

Under stringent conditions as described above, the target nucleotide sequence has at least 80% identity, preferably at least 85% identity, more preferably at least 90% identity, and even more preferably at least 95% identity. A gene comprising a base sequence having identity, particularly preferably at least 99% (upper limit 100%) identity, can hybridize with a gene comprising a base sequence complementary to the subject base sequence.

Examples of host microorganisms in the present invention include, but are not limited to, Escherichia coli, Bacillus subtilis, actinomycetes, yeast, and the like. Of these, Escherichia coli or Bacillus subtilis is preferably used, and Escherichia coli is more preferable because of the low metabolic activity of the aromatic compound as a raw material and the catechol compound as a product.

The Escherichia coli preferably used in the present invention can adopt a general strain used for protein expression and is not particularly limited. coli AD494, E. coli. coli B834, E. coli. coli BL21, E. coli. coli BLR, E. coli. E. coli HMS174, E. coli. coli Origami (registered trademark), E. coli. E. coli Rosetta (registered trademark), E. coli. E. coli Tuner (registered trademark), E. coli. coli JM109, E. coli. E. coli AD494 (DE3), E. coli. coli B834 (DE3), E. coli. coli BL21 (DE3), E. coli. coli BLR (DE3), E. coli. E. coli HMS174 (DE3), E. coli. coli Origami (DE3), E. coli. E. coli Rosetta (registered trademark) (DE3), E. coli. An example is E. coli Tuner (registered trademark) (DE3).

The microorganism used as the host is preferably an aromatic compound as a raw material and a product having a low metabolic activity as a product. Aromatic compounds that are raw materials and microorganisms (eg, Escherichia coli) that are inherently low in metabolic activity of catechol compounds may be used. However, such as 3-methylcatechol 2,3-dioxygenase (todE) can be obtained by gene disruption. Microorganisms that have lost the function of catechol compound-metabolizing enzymes may also be used. By using a microorganism having low aromatic compound metabolic activity as a raw material as a host, consumption of the aromatic compound through a route other than the synthesis of the catechol compound can be prevented. Moreover, the yield of a catechol compound can be improved by using a microorganism with low catechol compound metabolic activity as a host.

Furthermore, the microorganism used as the host may be a microorganism in which the function of alcohol dehydrogenase and / or aldehyde dehydrogenase is lost by gene disruption or the like. As a result, when an aromatic compound raw material such as 2-phenylethanol whose side chain is a hydroxyalkyl group is used, or in the catechol compound represented by the general formula (1), the side chain R is a hydroxyalkyl group In such a case, side chain oxidation can be suppressed.

A known method can be used for the gene disruption method. Specifically, a method of destroying the gene using a vector (targeting vector) that causes homologous recombination at an arbitrary position of the target gene (gene targeting method), or a trap vector (promoter at an arbitrary position of the target gene). Knockout cells, transgenic animals (including knockout animals), etc. in this technical field, such as methods that insert a reporter gene that does not possess) and destroy the gene to lose its function (gene trap method), methods that combine them, etc. A method used for manufacturing can be used. In addition, a method of introducing a vector expressing an antisense cDNA of a gene desired to be disrupted or a method of introducing a vector expressing a double-stranded RNA of a gene desired to be disrupted into a cell can be used. Such vectors include viral vectors, plasmid vectors, and the like, and can be prepared based on ordinary genetic engineering techniques. In addition, a commercially available vector can be cleaved with an arbitrary restriction enzyme, and a desired gene or the like can be incorporated and semi-synthesized. The position where homologous substitution occurs or the position where the trap vector is inserted is not particularly limited as long as it causes a mutation that eliminates the expression of the target gene to be disrupted, but preferably the transcription regulatory region is replaced.

The transformed microorganism used in the present invention introduces a recombinant vector incorporating an aromatic ring dioxygenase gene group and / or an aromatic ring dihydrodiol dehydrogenase gene into a host so that the target gene can be expressed. Or by inserting the gene of interest or a part thereof at any position on the genome by homologous recombination. The method for introducing and expressing the aromatic ring dioxygenase gene group and the aromatic ring dihydrodiol dehydrogenase gene into a microorganism such as Escherichia coli can be performed by a conventional method. Although not particularly limited, for example, a method using calcium ions generally used for introducing a vector into a microorganism, a protoplast method, an electroporation method, a heat shock method, and the like can be given.

The method of inserting the gene of interest at any position on the genome by homologous recombination is to insert the gene of interest together with the promoter into a sequence homologous to the sequence on the genome and introduce this nucleic acid fragment into the cell by electroporation or the like. Thus, it can be carried out by causing homologous recombination. At the time of introduction into the genome, a strain in which homologous recombination has occurred can be easily selected by using a nucleic acid fragment in which a target gene and a drug resistance gene are linked. In addition, a gene linked to a drug resistance gene and a gene that becomes lethal under specific conditions is inserted into the genome by homologous recombination by the above method, and then becomes lethal under specific conditions with the drug resistance gene. The target gene can also be introduced by homologous recombination in the form of replacing the gene.

When selecting a transformed microorganism into which a target gene has been introduced, the method is not particularly limited, but a method by which only a transformed microorganism into which a target gene has been introduced can be easily selected is preferred. For example, antibiotic resistance genes, methods using antibiotics such as ampicillin, kanamycin, streptomycin, chloramphenicol corresponding to these antibiotic resistance genes, or expression as a fusion protein of fluorescent protein or tag and target protein Conventionally known means such as a method may be employed. The expression of the target protein can also be confirmed by SDS-polyacrylamide gel electrophoresis or Western blotting. In addition, a transformed microorganism can be selected by the method described later, using as an index the production rate of 2- (2,3-dihydroxyphenyl) ethanol using 2-phenylethanol as a raw material.

In one preferred embodiment of the present invention, the aromatic ring dioxygenase gene group and the aromatic ring dihydrodiol dehydrogenase gene have a copy number ratio of the following cassette (1) and cassette (2) of 1: 1 to 5: 1. Introduce into the microorganism so that
Cassette (1): An IPTG-inducible promoter (1) and an aromatic ring dioxygenase gene group operatively linked to the promoter (1) and the aromatic ring dihydrodiol dehydrogenase gene. Cassette (2): IPTG inducibility A promoter (2), and an aromatic ring dihydrodiol dehydrogenase gene operably linked to the promoter (2).

The cassette (1) and cassette (2) may further contain a linker sequence for linking the promoter and the gene and a terminator region at the end of the gene.

FIG. 8 schematically shows the structure of the cassette (1) and the cassette (2). As shown in FIG. 8, in the cassette (1), an aromatic ring dioxygenase gene group (todC1 gene, todC2 gene, todB gene, todA gene) and an aromatic ring dihydrodiol dehydrogenase gene (todD gene) are located downstream of the promoter (1). (Hereinafter referred to as “cassette (1), the aromatic ring dioxygenase gene group and the aromatic ring dihydrodiol dehydrogenase gene are operatively linked downstream of the promoter (1)”. The “vector having the polynucleotide” is also simply referred to as “vector (1)”.) Further, as shown in FIG. 8, in the cassette (2), an aromatic ring dihydrodiol dehydrogenase gene (todD gene) is operably linked downstream of the promoter (2) (hereinafter referred to as “cassette (2)”. A vector having a polynucleotide in which an aromatic ring dihydrodiol dehydrogenase gene is operably linked downstream of the promoter (2) is also simply referred to as “vector (2)”). In the present specification, “operably linked” means that the expression of a gene (aromatic ring dioxygenase gene group, aromatic ring dihydrodiol dehydrogenase gene) is expressed by a promoter by the addition of an expression inducer (eg, IPTG). It means that the promoter and the gene are linked so as to induce.

In one embodiment of the present invention, the transformed microorganism operates an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene with the isopropyl β-thiogalactopyranoside inducible promoter (1) and the promoter (1). Operably linked to a cassette (1) comprising an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene, an isopropyl β-thiogalactopyranoside inducible promoter (2) and a promoter (2) The cassette (2) containing the aromatic ring dihydrodiol dehydrogenase gene thus introduced was introduced so that the copy number ratio of the cassette (1) and the cassette (2) was 1: 1 to 5: 1. When a catechol compound is produced using a transformed microorganism introduced with an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene prepared by such a technique, the selectivity of the catechol compound described later can be increased. The production rate of catechol compounds per unit time and unit cell concentration can be increased. Although it does not restrict | limit the technical scope of this invention, it is estimated that this is based on the following mechanisms. When the vector (2) and the vector (1) are combined and introduced into the host under the condition where the copy number ratio is 1: 1 or more, the above reaction formula ( The latter half of the reaction in 1) will be promoted. As a result, the dihydrodiol derivative is rapidly changed to a catechol compound, and it is presumed that the selectivity of the catechol compound and the production rate of the catechol compound per unit time / unit cell concentration are increased. When the copy number ratio between the vector (1) and the vector (2) is 5: 1 or less, the first half and second half reactions in the reaction formula (1) are appropriately balanced.

The cassette (1) and cassette (2) are introduced into the host in the state of being incorporated into the above-described vector such as pET (as the vector (1) and vector (2)). Cassette (1) and cassette (2) may be incorporated into the same vector in tandem, or may be incorporated into different vectors, but are preferably incorporated into the same vector in tandem. Since the cassette (1) and the cassette (2) are incorporated in the same vector in tandem, the types of antibiotics used for selection of transformed microorganisms can be reduced (for example, one type). . This probably reduces the damage to the microorganisms by antibiotics, the load of plasmid amplification, and the load of expression of drug resistance genes, thus promoting enzyme production. Therefore, it is possible to prepare a transformed microorganism having a higher catechol compound selectivity and a higher rate of catechol compound production per unit time and unit cell concentration.

The copy number ratio between the cassette (1) and the cassette (2) to be introduced into the host is preferably 1: 1 to 5: 1, more preferably 1.5: 1 to 4: 1. More preferably, it is 2: 1 to 3: 1. If it is the said range, the reaction rate of the reaction of the first half in Reaction formula (1) and the reaction of the latter half will be balanced, the selectivity of a catechol compound will become high, and the production | generation rate of a catechol compound can also be made high. The copy number ratio can be arbitrarily set by appropriately designing the number of cassettes (1) and cassettes (2) contained in the insertion sequence into the vector. In addition, the above copy number ratio corresponds to the copy number ratio of the vector (1) and the vector (2), so the copy number of the vector (1) and the vector (2) when introduced into the host is adjusted. It can be arbitrarily set depending on the situation.

The promoter (1) and promoter (2) are not particularly limited as long as they are IPTG-inducible, and for example, the above-described T7 promoter, lac promoter, tac promoter, trc promoter, spac promoter and the like can be used. Of these, the T7 promoter is preferably used from the viewpoint of high promoter activity. The promoter (1) and the promoter (2) contained in each of the cassette (1) and the cassette (2) may be the same promoter or different promoters, but from the viewpoint of easy induction control. , Preferably the same.

In addition, the aromatic ring dioxygenase gene group and the aromatic ring dihydrodiol dehydrogenase gene contained in the cassettes (1) and (2) may be derived from the same species or different organisms. The aromatic ring dioxygenase gene group contained in the cassette (1) is preferably a toluene dioxygenase gene group, more preferably a toluene dioxygenase gene group derived from Pseudomonas. The aromatic ring dihydrodiol dehydrogenase gene contained in the cassettes (1) and (2) is preferably a cis-toluene dihydrodiol dehydrogenase gene, and more preferably a cis-toluene dihydrodiol dehydrogenase gene derived from Pseudomonas. .

When the transformed microorganism is maintained and cultured, a medium usually used for maintenance culture of the transformed microorganism (hereinafter, a maintenance medium not containing IPTG and usually used for culturing the transformed microorganism is also referred to as “IPTG-free medium”). What is necessary is just to maintain by the normal culture method using this. The IPTG-free medium used for the maintenance culture of the transformed microorganism may be either a synthetic medium or a natural medium as long as it contains a carbon source, an appropriate amount of nitrogen source, inorganic salts and other nutrients that can be assimilated by the microorganism used. But you can. Usually, the IPTG-free medium contains a carbon source, a nitrogen source, and an inorganic substance.

The carbon source that can be used for the IPTG-free medium is not particularly limited as long as it is a carbon source that can be assimilated by the strain used. Specifically, in consideration of microbial utilization, glucose, fructose, cellobiose, raffinose, xylose, maltose, galactose, sorbose, glucosamine, ribose, arabinose, rhamnose, sucrose, trehalose, α-methyl-D-glucoside , Salicin, melibiose, lactose, melezitose, inulin, erythritol, glucitol, mannitol, galactitol, N-acetyl-D-glucosamine, starch, starch hydrolysate, molasses, molasses, and other natural products such as wheat and rice And alcohols such as glycerol, methanol and ethanol, organic acids such as acetic acid, lactic acid, succinic acid, gluconic acid, pyrpinic acid and citric acid, and hydrocarbons such as hexadecane. The carbon source is appropriately selected in view of assimilation by the microorganism to be cultured. Moreover, the said carbon source can be used 1 type or 2 types or more selected.

Nitrogen sources that can be used in the IPTG-free medium include meat extract, peptone, polypeptone, tryptone, yeast extract, malt extract, soybean hydrolysate, soybean powder, casein, milk casein, casamino acid, glycine, glutamic acid, aspartic acid Organic nitrogen sources such as various amino acids such as corn steep liquor, other animals, plants, microorganism hydrolysates; ammonium salts such as ammonia, ammonium nitrate, ammonium sulfate, ammonium chloride, nitrates such as sodium nitrate, sodium nitrite, etc. Examples thereof include inorganic nitrogen sources such as nitrite and urea. The nitrogen source is appropriately selected in view of assimilation by the microorganism to be cultured. Further, one or more of the nitrogen sources can be selected and used.

Inorganic materials that can be used in the IPTG-free medium include phosphates, hydrochlorides, sulfates, acetates, carbonates, chlorides, such as magnesium, manganese, calcium, sodium, potassium, copper, iron, zinc, tungsten and molybdenum. And the like, and hydrates thereof. The inorganic substance is appropriately selected in consideration of the requirements of the microorganism to be cultured. In addition, one or more of the above inorganic materials can be selected and used. In addition, vegetable oil, a surfactant, an antifoaming agent (for example, Adecanol (registered trademark) LG-109) and the like may be added to the IPTG-free medium as necessary. In addition, when transformation is performed using a vector having a sequence encoding an antibiotic resistance gene, ampicillin or kanamycin corresponding to the antibiotic resistance gene is used to maintain the character and prevent contamination by other microorganisms. Antibiotics such as streptomycin and chloramphenicol may be added to the IPTG-free medium.

The conditions for the maintenance culture are not particularly limited as long as the conditions are selected appropriately depending on the type of microorganism to be cultured, the composition of the medium and the culture method, and the microorganism can grow. Usually, the culture temperature is preferably 15 to 50 ° C., more preferably 15 to 37 ° C. Further, the pH of a medium suitable for culture is preferably 3 to 10, more preferably 5 to 8.

[Liquid containing isopropyl β-thiogalactopyranoside (liquid containing IPTG)]
In the present invention, a transformed microorganism into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene are introduced is cultured in a solution containing 5 to 100 μM IPTG. In one embodiment, a transformed microorganism into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene are introduced is cultured in a solution containing 5 to 30 μM IPTG. By culturing a transformed microorganism into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene are introduced in a liquid containing IPTG, protein expression of the aromatic ring dioxygenase and the aromatic ring dihydrodiol dehydrogenase is induced.

Generally, when protein expression is induced by IPTG, for example, as described in SUPPLEMENTENTARY MATERIAL in Non-Patent Document 1, the final concentration of IPTG is about 1 mM. Furthermore, in order to increase the target enzyme activity, generally, a method of increasing the expression level of the induced target protein by increasing the IPTG concentration in the culture solution is employed. On the other hand, in the preparation method according to the present invention, a transformed microorganism into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene have been introduced contains a liquid containing IPTG at a low concentration of 5 to 100 μM (for example, 5 to 30 μM). Incubate at By culturing the transformed microorganism in a solution containing a low concentration of IPTG, a transformed microorganism that efficiently synthesizes a catechol compound can be obtained. Although it does not limit the technical scope of the present invention at all, this is because the rate of protein production due to expression induction is reduced by lowering the concentration of IPTG added, thereby suppressing protein misfolding and activity. It is presumed that this is because the amount of soluble protein produced having increased.

The solution containing IPTG is prepared by adding IPTG to a medium (IPTG-free medium) usually used for culturing the above-described transformed microorganism. The concentration of IPTG in the entire liquid containing IPTG may be 5 to 100 μM. For example, the concentration of IPTG in the entire liquid containing IPTG is, for example, 5 to 30 μM, preferably 6 to 25 μM, more preferably 6 to 24 μM, still more preferably 7 to 23 μM, and particularly preferably 10 The effect of efficient synthesis of catechol compounds when the concentration of IPTG is ˜20 μM is the introduction of an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene operatively linked to the T7 promoter. This is particularly noticeable when using transformed microorganisms. For example, when using a transformed microorganism into which an aromatic ring dioxygenase gene group operatively linked to a tac promoter and an aromatic ring dihydrodiol dehydrogenase gene are used, the concentration of IPTG in the whole liquid containing IPTG is, for example, 15 Is 100 to 100 μM, preferably 25 to 100 μM, more preferably 30 to 95 μM, still more preferably 35 to 80 μM, and particularly preferably 35 to 60 μM. When the concentration of IPTG in the whole liquid containing IPTG is in the above numerical range, a catechol compound can be efficiently produced by the prepared transformed microorganism.

The culture method of the transformed microorganism in the liquid containing IPTG may be any method as long as the microorganism can grow and proliferate. Specifically, the above-mentioned conditions for maintenance culture are taken into consideration. The culture time in the liquid containing IPTG is not particularly limited, and varies depending on the type of microorganism to be cultured, the amount of medium, the culture conditions, and the like. When culturing at 25 ° C., the culture time is 5 to 96 hours, preferably 5 to 72 hours, more preferably 12 to 48 hours.

In the present invention, the dissolved oxygen concentration of the liquid containing IPTG is preferably more than 0 mg / L and not more than 5 mg / L. By culturing transformed microorganisms with a solution containing IPTG having a dissolved oxygen concentration of more than 0 mg / L and not more than 5 mg / L, catechol compounds can be efficiently used, especially when the culture volume is cultured in a large volume of 1 L or more. Can be prepared. Although it does not limit the technical scope of the present invention, it is presumed that this is due to inhibition of enzyme deactivation due to dissolved oxygen and enzyme deactivation associated with the progress of the reaction using a medium component as a substrate. The The dissolved oxygen concentration of the liquid containing IPTG is more preferably 0.1 to 5 mg / L, still more preferably 0.1 to 2 mg / L, and preferably 0.7 to 1.6 mg / L. Further preferred. Here, the above numerical range refers to the dissolved oxygen concentration (initial dissolved oxygen concentration) immediately after the start of expression induction by IPTG (within 5 minutes). During the cultivation, the dissolved oxygen concentration may fluctuate, but the dissolved oxygen concentration is 0 to 5 mg / L, exceeding 0 mg / L to 5 mg / L or less, 0 mg throughout the period of culturing the transformed microorganism with a solution containing IPTG. It is more preferable in this order that it is 2 mg / L or less exceeding / L.

It has a promoter region such as glyceraldehyde-3-phosphate dehydrogenase gene and 6-phosphofructokinase gene involved in glucose metabolism, and a promoter region such as glutamate decarboxylase gene involved in acid resistance mechanism in E. coli. Even in a transformed microorganism into which an expression vector has been introduced, the production efficiency of the catechol compound can be improved by culturing at the dissolved oxygen concentration as described above.

The dissolved oxygen concentration of the liquid containing IPTG can be arbitrarily set, for example, by adjusting the composition of the gas (aeration gas) that passes through the medium, the amount of aeration, and the stirring speed. By using an inert gas such as nitrogen or argon as the aeration gas, reducing the aeration amount, or reducing the stirring speed, the dissolved oxygen concentration of the liquid containing IPTG can be lowered. The mixing ratio of air and inert gas in the aeration gas is preferably 1: 0.5 to 20 (v: v) of air: inert gas, and 1: 3 to 9 (v: v). More preferably, it is 1: 4 to 9 (v: v). The air flow rate is, for example, 10 L / min or less, preferably 0.1 to 5 L / min, with respect to a liquid containing 1 L of IPTG.

When cultivating a transformed microorganism with a solution containing IPTG, the pH of the medium may fluctuate during the culture, and thus an acid or alkali may be added as appropriate to adjust the pH to a desired value. The acid or alkali is not particularly limited, but acids such as hydrochloric acid, nitric acid, sulfuric acid, and acetic acid, and alkalis such as sodium hydroxide and potassium hydroxide are used.

When protein expression is induced by IPTG, microbial growth may be inhibited. Therefore, in the preparation method according to the present invention, (i) the transformed microorganism is cultured in an IPTG-free medium; then (ii) the final concentration is 5 to 100 μM (for example, 5 to 30 μM or 15 to 100 μM). Thus, it is preferable to induce the expression of aromatic ring dioxygenase and aromatic ring dihydrodiol dehydrogenase by adding IPTG to the medium (cultured in a liquid containing IPTG). Expression induction can also be delayed by adding glucose at a final concentration of 0.5 to 1% (w / v) to the medium. When the transformed microorganism is cultured in a liquid containing IPTG after culturing in an IPTG-free medium, the timing of adding IPTG may be determined by measuring the cell concentration of the microorganism by turbidity measurement or the like. The timing of adding IPTG is, for example, when OD ₆₆₀ becomes 0.1 to 1. In addition, the transformed microorganism may be pre-cultured before the above (i) (cultivation of transformed microorganism in IPTG-free medium). Pre-culture makes it easy to adjust the cell concentration of the transformed microorganism. As the pre-culture conditions, the above-described maintenance culture conditions are considered.

The transformed microorganism prepared by the preparation method according to the present invention efficiently produces a catechol compound. The rate of formation of catechol compounds (hereinafter also referred to as “reaction rate”) is, for example, 2- (2,3-dihydroxy per unit time / unit cell concentration produced when 2-phenylethanol is used as a raw material. It is determined by the amount of phenyl) ethanol (mM / (h · OD ₆₆₀ )). Production of catechol compounds by the amount of 2- (2,3-dihydroxyphenyl) ethanol per unit time and unit cell concentration (mM / (h · OD ₆₆₀ )) produced when 2-phenylethanol is used as a raw material The speed is determined by the method described in the examples.

More specifically, it may be obtained by the following method. That is, 2 to 3 of a transformant microorganism and 4 ml of IPTG-free medium (for example, LB medium optionally containing an antibiotic corresponding to an antibiotic resistance gene in the case of Escherichia coli or Bacillus subtilis) are put in a test tube. Prepare this and perform shaking culture at 300 rpm overnight (about 14 to 18 hours) at 30 ° C. (preculture). Next, the OD ₆₆₀ of the culture solution after the pre-culture is measured, the culture solution is diluted in a jar fermenter, and the bacterial cell concentration is adjusted. The bacterial cell concentration can be adjusted by diluting the culture solution in an IPTG-free medium so that OD ₆₆₀ (initial OD ₆₆₀ ) is 0.05 and the reaction volume is 1 L. The IPTG-free medium used for dilution may be of the following composition if it is Escherichia coli or Bacillus subtilis. In addition, when using actinomycetes or yeast as the host, the medium to be used such as ISP medium (actinomycetes) or YPD medium (yeast) may be arbitrarily selected depending on the microorganism to be cultured.

The diluted culture solution is cultured (25 ° C., 725 rpm), and IPTG is added so that the final concentration becomes 10 μM when OD ₆₆₀ reaches 0.4 to 0.6. After adding IPTG, adjusting the pH at a temperature of 25 ° C. and a stirring rate of 725 rpm (adding 2N NaOH so that the lower limit of the pH is 6.0), the aeration rate is 1 L / min (aeration gas air: nitrogen gas is Incubate at 1: 4) for 24 hours. After culture, the cells are collected and washed with a phosphate buffer solution (pH 7.0) having the following composition. The microorganism prepared as described above is stored at −80 ° C. until the formation reaction of the catechol compound.

The phosphate buffer (pH 7.0) is added to the prepared microorganism and OD ₆₆₀ is measured (the microorganism suspension prepared by adding the buffer is also referred to as “microbe suspension”). From the measured OD _{660 of} the microorganism suspension, the dilution factor at which OD ₆₆₀ is 5.0 is determined. The following reaction solution is prepared so that the dilution rate of the microorganism suspension after the preparation of the reaction solution is the dilution rate thus determined. Reaction is performed using the prepared reaction solution (30 ° C., 300 rpm, 4 hours).

After the reaction, the produced 2- (2,3-dihydroxyphenyl) ethanol is analyzed by LC-MS. 2- (2,3-dihydroxyphenyl) ethanol may be quantified from the UV peak (retention time: 5.2 minutes, m / z: 155, 137).
(Analysis conditions by LC-MS)
MS: 3200QTRAP (AB Sciex)
Moving layer: Liquid A 0.1% formic acid Liquid B Acetonitrile column: Capsule pack AQ Particle diameter 3 μm Internal diameter 2 mm Length 25 cm
Column temperature: 40 ° C
Detection wavelength: 254 nm
Flow rate: 0.2 mL / min
Analysis time: 15 min
MASS mode: Q1 posi
Measurement m / z: 100-250
Gradient:

Based on the quantification result of 2- (2,3-dihydroxyphenyl) ethanol produced, 2- (2,3-dihydroxy per unit time and unit cell concentration produced when 20 mM 2-phenylethanol is used as a raw material. The amount of phenyl) ethanol (mM / (h · OD ₆₆₀ )) is calculated. At this time, the time (h) is 4 hours as the reaction time, and OD ₆₆₀ is 5.0 at the time of preparing the reaction solution.

In the preparation method according to the present invention, the production of 2- (2,3-dihydroxyphenyl) ethanol calculated by the above method using 2-phenylethanol as a raw material of a transformed microorganism cultured in a solution containing IPTG The speed is preferably 0.45 mM / (h · OD ₆₆₀ ) or more. More preferably, the production rate of 2- (2,3-dihydroxyphenyl) ethanol using 2-phenylethanol calculated by the above method is 0.50 mM / (h · OD ₆₆₀ ) or more, Preferably, it is 0.70 mM / (h · OD ₆₆₀ ) or more. The upper limit of the production rate of 2- (2,3-dihydroxyphenyl) ethanol when 2-phenylethanol is used as a raw material is not particularly limited, but is, for example, 1.60 mM / (h · OD ₆₆₀ ) or less ( For example, it is 1.57 mM / (h · OD ₆₆₀ ) or less). According to the preparation method of the present invention, when 2-phenylethanol is used as a raw material, 2- (2,3-dihydroxyphenyl) ethanol is produced at a rate of 0.45 mM / (h · OD ₆₆₀ ) or more. A transformed microorganism can be obtained.

In one embodiment of the present invention, the transformed microorganism comprises an isopropyl β-thiogalactopyranoside inducible promoter (1) and an aromatic ring dioxygenase gene group and an aromatic ring dihydro operably linked to the promoter (1). Cassette (1) containing diol dehydrogenase gene, isopropyl β-thiogalactopyranoside inducible promoter (2) and cassette (2) containing aromatic ring dihydrodiol dehydrogenase gene operably linked to said promoter (2) Are introduced into the microorganism so that the copy number ratio between the cassette (1) and the cassette (2) is 1: 1 to 5: 1. In a further embodiment of the invention, said promoter (1) and said promoter (2) are T7 promoter or tac promoter.

[Method for producing catechol compound]
The second aspect of the present invention relates to a method for producing a catechol compound represented by the following general formula (1) using a transformed microorganism prepared by the above preparation method. According to the second aspect of the present invention, there is provided an efficient method for producing a catechol compound using a transformed microorganism prepared by the method. According to the second aspect of the present invention, there is provided an efficient method for producing a catechol compound using a transformed microorganism prepared by the method.

In the general formula (1), R is a hydrogen atom, a halogen atom, a phenyl group, a heterocyclic group, or a group represented by the following general formula (2). In the present specification, the “heterocyclic group” is a group composed of a 5- to 10-membered heterocyclic ring. Specific examples of the heterocyclic ring include furan, thiophene, pyrrole, imidazole, pyrazole, thiazole, isothiazole, and oxazole. , Pyrrolidine, pyran, pyridine, pyrimidine, pyrazine, piperidine, piperazine, morpholine, indole, indanone, benzofuran, benzimidazole, benzothiazole, benzoxazole, purine, quinoline, isoquinoline, chromene, chromen-4-one, chroman and chroman- 4-on can be exemplified.

Preferably, in the general formula (1), R is represented by a hydrogen atom, a halogen atom, or the following general formula (2).

In the general formula (2), x is 0 or 1, Y is a linear or branched alkylene group having 1 to 5 carbon atoms, and Z is a hydrogen atom or a hydroxyl group. Preferably, x is 0 or 1, Y is a linear or branched alkylene group having 1 to 3 carbon atoms, and Z is a hydrogen atom or a hydroxyl group. More preferably, x is 0 or 1, Y is — (CH ₂ ) _n — (n is an integer of 1 to 3), and Z is a hydroxyl group.

More specifically, the catechol compound represented by the general formula (1) includes catechol, 3-fluorocatechol, 3-chlorocatechol, 3-bromocatechol, 3-iodocatechol, 3-phenylcatechol, 3-methylcatechol. 3-ethyl catechol, 3-n-propyl catechol, 3-isopropyl catechol, 3-n-butyl catechol, 3-sec-butyl catechol, 3-tert-butyl catechol, 3-methoxy catechol, 3-ethoxy catechol, 3 -N-propoxycatechol, 3-isopropoxycatechol, 3-n-butoxycatechol, 3-sec-butoxycatechol, 3-tert-butoxycatechol, 2,3-dihydroxybenzyl alcohol, (2,3-dihydroxyphenoxy) methanol 1- (2,3-dihydroxyphenyl) ethanol, 1- (2,3-dihydroxyphenoxy) ethanol, 2- (2,3-dihydroxyphenyl) ethanol, 2- (2,3-dihydroxyphenoxy) ethanol, 1 -(2,3-dihydroxyphenyl) -1-propyl alcohol, 1- (2,3-dihydroxyphenyl) -2-propyl alcohol, 1- (2,3-dihydroxyphenoxy) -1-propyl alcohol, 1- ( 2,3-dihydroxyphenoxy) -2-propyl alcohol, 2- (2,3-dihydroxyphenyl) -1-propyl alcohol, 2- (2,3-dihydroxyphenyl) -2-propyl alcohol, 2- (2, 3-dihydroxyphenoxy) -1-propyl alcohol, 2- (2,3-dihydroxy Enoxy) -2-propyl alcohol, 3- (2,3-dihydroxyphenyl) -1-propyl alcohol, 3- (2,3-dihydroxyphenoxy) -1-propyl alcohol, 2- (2,3-dihydroxyphenyl) -Pyridine, 2- (2,3-dihydroxyphenyl) -indole, 2- (2,3-dihydroxyphenyl) -indan-1-one, 3- (2,3-dihydroxyphenyl) -indan-1-one, 2- (2,3-dihydroxyphenyl) -quinoline, 2- (2,3-dihydroxyphenyl) -benzoxazole, 2- (2,3-dihydroxyphenyl) -chromen-4-one, 2- (2,3 -Dihydroxyphenyl) -chroman-4-one and the like.

In the production method according to the present invention, the transformed microorganism prepared by the above method is brought into contact with an aromatic compound raw material. As aromatic compound raw materials, benzene, fluorobenzene, chlorobenzene, bromobenzene, iodobenzene, biphenyl, toluene (methylbenzene), anisole (methoxybenzene), benzyl alcohol (phenylmethanol), phenoxymethanol, phenylethane, phenoxyethane, 1-phenylethanol, 2-phenylethanol, 1-phenoxyethanol, 2-phenoxyethanol, 1-phenyl-propane, 1-phenoxy-propane, 1-phenyl-1-propyl alcohol, 1-phenyl-2-propyl alcohol, 1- Phenoxy-1-propyl alcohol, 1-phenoxy-2-propyl alcohol, 2-phenyl-propane, 2-phenoxy-propane, 2-phenyl-1-propyl alcohol, -Phenyl-2-propyl alcohol, 2-phenoxy-1-propyl alcohol, 2-phenoxy-2-propyl alcohol, 3-phenyl-1-propyl alcohol, 3-phenoxy-1-propyl alcohol, 2-phenyl-pyridine, 2-phenyl-indole, 2-phenyl-indan-1-one, 3-phenyl-indan-1-one, 2-phenyl-quinoline, 2-phenyl-benzoxazole, 2-phenyl-chromen-4-one, 2 Examples thereof include -phenyl-chroman-4-one.

In the production method according to the present invention, a synthetic reaction of a catechol compound can be performed by adding an aromatic compound raw material to a culture solution (a solution containing IPTG) containing a transformed microorganism prepared by the above method. That is, as the reaction solvent, a liquid containing a medium component can also be used. However, when a medium component is included in the reaction field, the reaction may be inhibited by glucose metabolites such as acetic acid, the product may be difficult to purify, or a by-product may be generated. Therefore, in the present invention, the transformed microorganism prepared by the above method is collected, and the catechol compound is produced by a resting cell reaction in which the synthesis reaction of the catechol compound is performed in a liquid not containing a medium component. Is preferred. When performing a catechol compound synthesis reaction by resting cell reaction, reaction solvents used include GOOD buffers such as BES, HEPES, TES, bicine, and tricine, amino acid buffers such as glycine-NaOH, phosphate buffers, Buffers such as Tris-HCl buffer, acetate buffer, and borate buffer are preferred. As the pH of the buffer solution, one having a pH of about 4.0 to 10.0 is usually used. The buffer includes halogens such as phosphate, hydrochloride, sulfate, acetate, carbonate, and chloride, such as magnesium, calcium, sodium, potassium, copper, and iron, depending on the nature of the enzyme. An inorganic component such as a chemical compound may be added.

For collection of bacteria, for example, the culture solution may be centrifuged at 1000 to 10,000 × g, and the precipitate (bacterial cell fraction) may be collected. A buffer appropriately selected according to the microorganism may be added to the microorganism thus collected, and the microorganism may be suspended to wash the microorganism. As a buffer used for washing | cleaning of microorganisms, the buffer used for the above-mentioned resting cell reaction can be illustrated, for example. Washing may be performed multiple times. The transformed microorganism prepared by culturing in a solution containing IPTG may be stored frozen (for example, at −80 ° C.) until the catechol compound production reaction. Freezing of the transformed microorganism after preparation is preferably performed after collection to reduce the liquid volume.

The concentration of the aromatic compound raw material in the reaction solution can be adjusted within a range where the influence of substrate inhibition does not occur. In the production method according to the present invention, the concentration of the aromatic compound raw material is preferably 1 to 100 mM, and more preferably 5 to 50 mM. The amount of the transformed microorganism collected in the reaction solution is, for example, an amount at which OD ₆₆₀ is 0.5 to 100 at the start of the reaction, preferably an amount at which OD ₆₆₀ is 1 to 40. is there. In order to adjust the OD ₆₆₀ in the reaction solution of the transformed microorganism to the above range, the transformed microorganism prepared by the preparation method according to the present invention is diluted as necessary to obtain OD ₆₆₀ , and the OD ₆₆₀ in the reaction solution is obtained. What is necessary is just to calculate the dilution rate from which _OD660 becomes a desired value, and determine the addition amount of the microbial cell to a reaction liquid.

In the production method according to the present invention, the aromatic compound raw material used for the production of the catechol compound may be sequentially added to the reaction solution. By sequentially adding the substrate, the production scale-up can be facilitated and the selectivity can be increased. In this case, the “selectivity” is a value represented by the following formula 1. When the substrate is added sequentially, a transformed microorganism (transformed microorganism suspension) may also be added.

The reaction temperature in the production of the catechol compound may be arbitrarily set, and is, for example, 10 to 60 ° C., preferably 20 to 40 ° C. By setting the reaction temperature to 10 ° C. or higher, it is possible to prevent a decrease in the reaction rate. In addition, by carrying out the reaction at 60 ° C. or lower, inactivation of the aromatic ring dioxygenase or aromatic ring dihydrodiol dehydrogenase can be prevented. The reaction is preferably performed with stirring at, for example, 100 to 1000 rpm. The reaction time may be arbitrarily set depending on the production scale and the like, but is usually 1 to 48 hours.

The obtained product can be purified by any method such as solvent extraction, distillation, crystallization, salting out, chromatography, treatment with an adsorbent such as activated carbon. In addition, the structure and production amount of the product (catechol compound) obtained by synthesis include, for example, LC and GC described in Examples, and methods using MS combined with these, NMR, infrared spectroscopy, etc. This can be confirmed by means known to those skilled in the art.

[Composition, whitening agent, oxygen absorber]
In the third aspect of the present invention, the monohydration with respect to 100 mol of the catechol compound, comprising a catechol compound represented by the following general formula (1) and a monohydroxide represented by the following general formula (3): Compositions are provided wherein the proportion of the product is 0.002 to 5 moles. According to the third aspect of the present invention, a catechol compound-containing composition having excellent stability is provided.

In the general formula (1), R is a hydrogen atom, a halogen atom, a phenyl group, a heterocyclic group, or a group represented by the following general formula (2).

In the general formula (2), x is 0 or 1, Y is a linear or branched alkylene group having 1 to 5 carbon atoms, and Z is a hydrogen atom or a hydroxyl group.

In the third aspect of the present invention, the definitions of R, x, Y, and Z in the general formulas (1) and (2) are the same as the definitions in the second aspect, and the explanation in the second aspect. Is appropriately modified and applied to the third aspect.

In the general formula (3), R ′ is a heterocyclic group or a group represented by the following general formula (4).

In the general formula (4), x ′ is 0 or 1, Y ′ is a linear or branched alkylene group having 1 to 5 carbon atoms, and Z ′ is a hydrogen atom or a hydroxyl group.

In the third aspect of the present invention, R ′ in the general formula (3) is applied by appropriately modifying the description of R in the general formula (1). In the third aspect of the present invention, x ′, Y ′, and Z ′ in the general formula (4) have the same definitions as x, Y, and Z in the general formula (2), respectively. The description of the general formula (2) is appropriately modified and applied. In the general formula (3), the hydroxyl group may be in the ortho position, the meta position or the para position, but is preferably the ortho position or the meta position, more preferably the ortho position.

More specifically, the monohydroxide represented by the general formula (3) is, for example, 2-hydroxybenzyl alcohol, 3-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, 2-hydroxyphenoxymethanol, 3-hydroxyphenoxy. Methanol, 4-hydroxyphenoxymethanol, 1- (2-hydroxyphenyl) ethanol, 1- (3-hydroxyphenyl) ethanol, 1- (2-hydroxyphenoxy) ethanol, 1- (3-hydroxyphenoxy) ethanol, 2- (2-hydroxyphenyl) ethanol, 2- (3-hydroxyphenyl) ethanol, 2- (4-hydroxyphenyl) ethanol (tyrosol), 2- (2-hydroxyphenoxy) ethanol, 2- (3-hydroxyphenoxy) ethane 2- (4-hydroxyphenoxy) ethanol, 1- (2-hydroxyphenyl) -1-propyl alcohol, 1- (2-hydroxyphenyl) -2-propyl alcohol, 1- (2-hydroxyphenoxy)- 1-propyl alcohol, 1- (2-hydroxyphenoxy) -2-propyl alcohol, 2- (2-hydroxyphenyl) -1-propyl alcohol, 2- (2-hydroxyphenyl) -2-propyl alcohol, 2- ( 2-hydroxyphenoxy) -1-propyl alcohol, 2- (2-hydroxyphenoxy) -2-propyl alcohol, 3- (2-hydroxyphenyl) -1-propyl alcohol, 3- (2-hydroxyphenoxy) -1- Propyl alcohol, 2- (2-hydroxyphenyl) -pyridine, 2 (2-hydroxyphenyl) -indole, 2- (2-hydroxyphenyl) -indan-1-one, 3- (2-hydroxyphenyl) -indan-1-one, 2- (2-hydroxyphenyl) -quinoline, Examples include 2- (2-hydroxyphenyl) -benzoxazole, 2- (2-hydroxyphenyl) -chromen-4-one, 2- (2-hydroxyphenyl) -chroman-4-one, and the like.

It is preferable that R of the catechol compound represented by the general formula (1) included in the composition and R ′ of the monohydroxide represented by the general formula (3) are the same.

As described later, the catechol compound represented by the general formula (1) has a whitening effect. On the other hand, in addition to the catechol compound represented by the general formula (1), the composition containing the monohydroxide represented by the general formula (3) in a predetermined range has a higher stability than the case of the catechol compound alone. The present inventors have found that the properties (particularly, the degradation of catechol compounds and the suppression of coloring) are achieved. Although it does not restrict | limit the technical scope of this invention, it is estimated that this is based on the following mechanisms. That is, when a monohydroxide that is easily oxidized as represented by the general formula (3) is contained in the composition, oxygen in the composition is trapped and the oxidation stability of the catechol compound is increased. Guessed.

In the composition according to the present invention, 100 moles of the catechol compound represented by the general formula (1) (the “catechol compound represented by the general formula (1)” is also simply referred to as “the catechol compound according to the present invention”). On the other hand, the monohydroxide represented by the general formula (3) ("monohydroxide represented by the general formula (3)" is also simply referred to as "monohydroxide according to the present invention") is 0. It is contained at a ratio of 002 to 5 mol. When the composition contains the monohydroxide according to the present invention at a ratio of 0.002 mol or more with respect to 100 mol of the catechol compound according to the present invention, high oxidation stability can be obtained. Further, when the proportion of the monohydroxide according to the present invention is 5 mol or less with respect to 100 mol of the catechol compound according to the present invention, the catechol compound according to the present invention has an influence on functions such as whitening effect. There is an advantage that it can be suppressed. The content of the catechol compound represented by the general formula (1) and the monohydroxide represented by the general formula (3) in the composition can be measured, for example, by the gas chromatography method described in the examples. When measuring the content in the composition of the monohydroxide represented by the general formula (3) by gas chromatography or the like, the measurement sample may be concentrated after measurement if necessary. Preferably, the composition according to the present invention contains 0.005 to 5 mol of the monohydroxide represented by the general formula (3) with respect to 100 mol of the catechol compound represented by the general formula (1). Contained, more preferably 0.01 to 1 mole.

The content of the catechol compound represented by the general formula (1) is, for example, 95 to 99.998 mol% in the composition. Further, the content of the monohydroxide represented by the general formula (3) is, for example, 0.002 to 5 mol% in the composition.

In a further embodiment of the present invention, the composition according to the present invention comprises 99.998 to 95 mol% of the catechol compound represented by the general formula (1), and 0.002 to 5 mol% of the total composition. It consists of a monohydroxide represented by the general formula (3) (however, the total amount of the catechol compound represented by the general formula (1) and the monohydroxide represented by the general formula (3) is 100 mol%. is there.). In another preferred embodiment, the composition according to the present invention is represented by 0.005 to 5 mol% of a catechol compound represented by the general formula (1) and 95 to 99.995 mol% of a general formula (3). (However, the total amount of the catechol compound represented by the general formula (1) and the monohydroxide represented by the general formula (3) is 100 mol%). In another more preferred embodiment, the composition according to the present invention comprises 0.01 to 1 mol% of a catechol compound represented by the general formula (1) and 99 to 99.99 mol% of a general formula (3). (The total amount of the catechol compound represented by the general formula (1) and the monohydroxide represented by the general formula (3) is 100 mol%).

The composition containing the catechol compound according to the present invention and the monohydroxide according to the present invention is obtained by adding the monohydroxide according to the present invention at a desired ratio to the separated and purified catechol compound according to the present invention. It can also be prepared.

Further, when a catechol compound is produced using a transformed microorganism into which an aromatic ring dioxygenase and an aromatic ring dihydrodiol dehydrogenase have been introduced (for example, a transformed microorganism prepared by the preparation method according to the present invention), the present invention is used as a by-product. The monohydroxide according to can also be produced. Although it does not restrict | limit the technical scope of this invention, it is estimated that this is based on the following mechanisms. That is, in the above reaction formula (1), a hydroxyl group is added to an aromatic compound one by one with respect to two adjacent carbon atoms by an aromatic ring dioxygenase, and then water molecules are spontaneously desorbed. It is presumed that a monohydroxide according to the above is generated. Therefore, in one embodiment of the present invention, the catechol compound represented by the general formula (1) and the monohydroxide represented by the general formula (3) contained in the composition are aromatic ring dioxygenase and aromatic ring dihydrodiol dehydrogenase. It is produced by oxidizing an aromatic compound raw material using a transformed microorganism into which is introduced. In one embodiment, the transformed microorganism is a transformed microorganism prepared by the adjustment method described above.

When a catechol compound is produced using a transformed microorganism into which an aromatic ring dioxygenase and an aromatic ring dihydrodiol dehydrogenase are introduced, usually, the R of the catechol compound represented by the general formula (1) and the general formula (3) R ′ of the monohydroxide represented is the same. In this case, in the monohydroxide represented by the general formula (3), the hydroxyl group is in the ortho position or the meta position.

When producing the catechol compound according to the present invention and the monohydroxide according to the present invention using a transformed microorganism into which an aromatic ring dioxygenase and an aromatic ring dihydrodiol dehydrogenase are introduced, the catechol compound represented by the general formula (1) (E.g., introducing cassette (2) in addition to cassette (1) into the microorganism, increasing the reaction time), thereby reducing the monohydroxide content according to the present invention in the product ( The amount of the catechol compound according to the present invention can be increased). On the other hand, by reducing the selectivity of the catechol compound represented by the general formula (1), the monohydroxide content according to the present invention in the product can be increased (the amount of the catechol compound according to the present invention is reduced). it can. The product obtained by such a technique can be used as the composition according to the present invention. Further, the amount of the catechol compound according to the present invention and the content of the monohydric acid according to the present invention in the composition may be adjusted by appropriately combining separation and purification techniques after the production of the catechol compound using the transformed microorganism. . In this case, in one embodiment, in the composition of the present invention, the total amount of the catechol compound according to the present invention and the monohydroxide according to the present invention is 98 to 100% by mass, preferably based on the whole composition. Is separated and purified to 99 to 100% by mass. The content of the catechol compound according to the present invention and the monohydroxide according to the present invention contained in the composition can be measured by the method described in the following examples.

(Whitening agent)
The catechol compound represented by the general formula (1) has a whitening effect. Since the composition according to the present invention contains a monohydroxide represented by the general formula (3) in addition to the catechol compound represented by the general formula (1), the composition is excellent in stability. Therefore, the composition according to the present invention can be used as a whitening agent having excellent stability. In one embodiment of the present invention, a whitening agent comprising the composition of the present invention is provided.

When the composition according to the present invention is used as a whitening agent, x is preferably 1 in the general formula (2). Moreover, when using the composition based on this invention as a whitening agent, it is preferable that x 'is 1 in General formula (4). When x and x 'are 1, a higher whitening effect can be obtained.

The composition of the present invention contained in the whitening agent is, for example, 0.0005% by mass or more, preferably 0.001% by mass or more, and more preferably 0.003% by mass or more. Although the upper limit of the composition of the present invention contained in the whitening agent is not particularly limited, it is, for example, 1% by mass or less, preferably 0.1% by mass or less, from the viewpoint of production cost. Examples of the whitening agent include lotion, cosmetic milk, cosmetic liquid, cosmetic gel, cosmetic soap, cleansing cream, facial cleanser, skin cream, skin milk, emollient cream, cosmetic oil, pack, tanning oil, and tanning. Stop oils, sun lotions, sunscreen lotions, sun creams, sun creams, foundations, lipsticks, lip balms, toothpastes, deodorants, lip balms and the like.

Further, the whitening agent is a range of other whitening components other than the catechol compound according to the present invention, such as sorbitan fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkyl ether, etc. Oils such as surfactants, squalane, liquid paraffin, paraffin wax, hydrocarbons such as petroleum jelly, fatty acid esters such as isopropyl palmitate and butyl stearate, silicone oils such as dimethicone and cyclomethicone, beeswax, olive oil and safflower oil Alcohols such as ethanol, cetyl alcohol, 2-octyldodecanol, isostearyl alcohol, polyhydric alcohols such as glycerin, propylene glycol, butylene glycol, sodium chloride, magnesium sulfate Which stabilizers, vitamins such as vitamin A, vitamin B group, vitamin C, vitamin E, thickeners such as carboxymethylcellulose, polyvinyl alcohol, carrageenan, clay minerals such as silica, talc, mica, kaolin, bentonite, methylparaben, etc. Preservatives, anti-inflammatory agents such as glycyrrhetinate, PABA-based, cinnamic acid-based, benzophenone-based, salicylic acid-based organic UV absorbers, amino acids, glycyrrhizinate, emulsifier, fragrance, dye, pigment, antioxidant You may mix | blend well-known components, such as an agent, an astringent, a cell activator, a moisturizer, a rough skin improving agent, a cosmetic ingredient, a pH adjuster, a binder, and a keratin improving agent suitably.

(Oxygen absorber)
The catechol compound represented by the general formula (1) has an oxygen absorbing action. In one embodiment of the present invention, an oxygen absorber is provided comprising the composition of the present invention.

The oxygen absorbent may be composed only of the composition according to the present invention. For example, alcohols such as glycerin and ethylene glycol, sugar alcohols such as sorbitol, ascorbic acid, hydroquinone, pyrogallol, gallic acid, resorcin and derivatives thereof Main components of conventionally known oxygen scavengers such as: transition metals such as iron, copper, manganese, nickel, etc., and their halides (eg, chlorides), sulfates, nitrates, phosphates, which are catalysts for the reaction of the main components , Transition metal compounds such as carbonates, oxides, hydroxides; activated carbon, graphite, carbon black, silica, kaolin, talc, bentonite, zeolite, perlite, diatomaceous earth, activated clay, calcium silicate, magnesium oxide, calcium hydroxide A carrier such as the above may be contained in an arbitrary ratio.

The composition of the present invention contained in the oxygen absorbent is, for example, 0.0001 to 20% by weight with respect to the whole oxygen absorbent. In one embodiment, 0.001 to 0.1 parts by weight of the composition according to the invention is used per 100 parts by weight of carrier.

The oxygen absorbent according to the present invention can be used for, for example, foods, cosmetics, pharmaceuticals, chemical products, electronic materials and the like.

[Embodiment]
The preferred embodiments of the present invention are shown below.
1. A method for preparing a transformed microorganism, comprising culturing a transformed microorganism into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene have been introduced in a solution containing 5 to 100 μM of isopropyl β-thiogalactopyranoside.
2. 2. The preparation method according to 1, wherein the solution containing isopropyl β-thiogalactopyranoside has a dissolved oxygen concentration of more than 0 mg / L and not more than 5 mg / L.
3. The preparation method according to 1 or 2, wherein the microorganism is Escherichia coli.
4). 4. The preparation method according to any one of 1 to 3, wherein the aromatic ring dioxygenase gene group is a toluene dioxygenase gene group.
5. 5. The preparation method according to 4, wherein the toluene dioxygenase gene group is derived from Pseudomonas putida.
6). 6. The preparation method according to any one of 1 to 5, wherein the aromatic ring dihydrodiol dehydrogenase gene is a cis-toluene dihydrodiol dehydrogenase gene.
7. 7. The preparation method according to 6, wherein the cis-toluene dihydrodiol dehydrogenase gene is derived from Pseudomonas putida.
8). When the transformed microorganism cultured in the solution containing isopropyl β-thiogalactopyranoside uses 2-phenylethanol as a raw material, 2- (2,3-dihydroxyphenyl) ethanol is 0.45 mM / (h · OD ₆₆₀ ) The preparation method according to any one of 1 to 7, which is produced at a rate of not less than 1.
9. The transformed microorganism comprises the aromatic ring dioxygenase gene group and the aromatic ring dihydrodiol dehydrogenase gene,
An isopropyl β-thiogalactopyranoside inducible promoter (1) and the aromatic ring dioxygenase gene group operably linked to the promoter (1) and a cassette (1) comprising the aromatic ring dihydrodiol dehydrogenase gene;
An isopropyl β-thiogalactopyranoside inducible promoter (2) and a cassette (2) comprising the aromatic ring dihydrodiol dehydrogenase gene operably linked to the promoter (2),
9. The preparation method according to any one of 1 to 8, which is introduced so that a copy number ratio of the cassette (1) and the cassette (2) is 1: 1 to 5: 1.
10. The following general formula (1) using a transformed microorganism prepared by the preparation method according to any one of 1 to 9:

In the general formula (2), x is 0 or 1, Y is a linear or branched alkylene group having 1 to 5 carbon atoms, and Z is a hydrogen atom or a hydroxyl group;
The manufacturing method of the catechol compound represented by these.
11. 11. The production method according to 10, wherein the catechol compound is produced by a resting cell reaction.
12 A transformed microorganism that produces 2- (2,3-dihydroxyphenyl) ethanol at a rate of 0.45 mM / (h · OD ₆₆₀ ) or more when 2-phenylethanol is used as a raw material.
13. An isopropyl β-thiogalactopyranoside inducible promoter (1) and a cassette (1) comprising an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene operably linked to said promoter (1);
An isopropyl β-thiogalactopyranoside inducible promoter (2) and a cassette (2) containing an aromatic ring dihydrodiol dehydrogenase gene operably linked to said promoter (2),
13. The transformed microorganism according to 12, which is introduced into the microorganism so that the copy number ratio between the cassette (1) and the cassette (2) is 1: 1 to 5: 1.
14 14. The transformed microorganism according to 13, wherein the promoter (1) and the promoter (2) are T7 promoter or tac promoter.
15. The following general formula (1):

In the general formula (4), x ′ is 0 or 1, Y ′ is a linear or branched alkylene group having 1 to 5 carbon atoms, and Z ′ is a hydrogen atom or a hydroxyl group;
Including a monohydroxide represented by
A composition wherein the ratio of the monohydroxide to 100 mol of the catechol compound is 0.002 to 5 mol.
16. A whitening agent or an oxygen absorbent comprising the composition according to 15.

The effect of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples.

[Production of transformed microorganisms]
Pseudomonas putida F1 strain (ATCC 700007) toluene dioxygenase gene group (todA: SEQ ID NO: 9, todB: SEQ ID NO: 8, todC1: SEQ ID NO: 6, todC2: SEQ ID NO: 7) and cis-toluene dihydrodiol dehydrogenase gene (todD: A recombinant plasmid, todA-D / pET21-, in which a DNA region containing SEQ ID NO: 10) is inserted into an expression vector pET21-b (+) (Novagen, having a T7 promoter sequence and a sequence encoding an ampicillin resistance gene) b (+) was constructed by the following procedure.

That is, P.I. Using the genomic DNA of putida F1 strain as a template, PCR amplification was performed using the following primers and Phusion High-Fidelity DNA Polymerase (Finzymes) to obtain todA-D fragment 1.

Using pET21-b (+) as a template, PCR amplification was performed using the following primers and Phusion High-Fidelity DNA Polymerase (Finzymes) to obtain a pET21-b (+) fragment.

Using the todA-D fragment 1 and pET21-b (+) fragment (including T7 promoter sequence) obtained by PCR amplification as described above, cloning was performed according to the protocol of the In-Fusion PCR cloning kit (Takara) and recombination. A plasmid, todA-D / pET21-b (+) was constructed. The cloning host is E. coli. E. coli DH5α (Takara Bio Inc.) was used.

The obtained recombinant plasmid and pET21-b (+) into which no gene has been introduced were transformed into E. coli. E. coli BL21 (DE3) (Invitrogen) was transformed by the heat shock method. E. coli BL21 (DE3) / (todA-D / pET21-b (+)) and E. coli. coli BL21 (DE3) / pET21-b (+) was obtained. A glycerol stock of the obtained transformed Escherichia coli was prepared and stored at −80 ° C. until preparation of transformed microorganisms described later (Examples 1 to 5).

[Example 1: Reaction using 2-phenylethanol (PEA) as a substrate]
(1) Preparation of transformed microorganisms coli BL21 (DE3) / (todA-D / pET21-b (+)) was induced to induce IPTG expression according to the following procedure.

The strain was inoculated into 4 mL of liquid medium A (test tube) and incubated (30 ° C., 300 rpm, overnight, preculture). Subsequently, a preculture was inoculated into liquid medium A (100 ml) so that the initial OD ₆₆₀ was 0.05 (Sakaguchi flask) and incubated (25 ° C., 120 rpm). When OD ₆₆₀ was 0.4 to 0.5 (about 4 hours of culture), IPTG (manufactured by Wako Pure Chemical Industries, Ltd.) was added and incubated (25 ° C., 120 rpm, culture) so that the final concentration was 100 μM. 24 hours from the start). Bacteria were collected and washed with phosphate buffer A (pH 7.0), and then stored frozen at −80 ° C. until used for the synthesis of catechol compounds.

(2) Synthesis of catechol compound using transformed microorganism Frozen cells were suspended in phosphate buffer A (pH 7.0) to prepare the following reaction solution (3 ml), and the reaction was started (30 ° C. , 300 rpm, 24 hours). 2-Phenylethanol was purchased from Wako Pure Chemical. The bacterial cell concentration was adjusted as follows. That is, the above-described phosphate buffer A was added to the microorganism prepared by the above-described method to prepare a microorganism suspension, and OD ₆₆₀ was measured. From the measured OD _{660 of} the microorganism suspension, the dilution factor at which OD ₆₆₀ was 10.0 was determined. The amount of cells was adjusted so that the dilution rate of the microorganism suspension after the reaction solution preparation was the dilution rate thus determined. The same applies to the following embodiments.

The reaction solution was analyzed by LC-MS and GC-MS. In the TIC chromatogram, a peak detected only when the substrate was added was confirmed at a retention time of 13.7 minutes. From the product ion, it was confirmed that the peak was 2- (2,3-dihydroxyphenyl) ethanol. Mass spectra for the TIC chromatogram and the peak with a retention time of 13.7 minutes are shown in FIGS. In addition, LC-MS and GC-MS analysis conditions and a summary of MS analysis results are shown below.

(Analysis conditions for LC-MS)
MS: 3200QTRAP (AB Sciex)
Moving layer: Liquid A 0.1% formic acid Liquid B Acetonitrile column: Capsule pack AQ Particle diameter 3 μm Internal diameter 2 mm Length 25 cm
Column temperature: 40 ° C
Detection wavelength: 254 nm
Flow rate: 0.2 mL / min
Analysis time: 15 min
MASS mode: Q1 posi
Measurement m / z: 100-250

(GC-MS analysis conditions)
Equipment: GCMS-QP2010 (manufactured by Shimadzu Corporation)
Column: DB-17HT (manufactured by Agilent)
Column oven program:

Vaporization chamber temperature: 250 ° C
Injection mode: Split control mode: Linear velocity Linear velocity: 38.1 cm / sec
Pressure: 77.0kPa
Ion source temperature: 200 ° C
Interface temperature: 250 ° C

The structures of 2-phenylethanol used as a substrate and the product catechol compound 2- (2,3-dihydroxyphenyl) ethanol are shown below.

[Example 2: Reaction using 2-phenoxyethanol as a substrate]
(1) Preparation of transformed microorganisms coli BL21 (DE3) / (todA-D / pET21-b (+)) was induced to induce IPTG expression according to the following procedure.

The strain was inoculated into 4 mL of liquid medium A (test tube) and incubated (30 ° C., 300 rpm, overnight, preculture). Subsequently, a preculture was inoculated into liquid medium A (100 ml) so that the initial OD ₆₆₀ was 0.05 (Sakaguchi flask) and incubated (25 ° C., 120 rpm). When the OD ₆₆₀ was 0.4 to 0.5 (about 4 hours of culture), IPTG (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the final concentration of 10 μM and incubated (25 ° C., 120 rpm, culture) 24 hours from the start). Bacteria were collected and washed with phosphate buffer B (pH 7.0), and stored frozen at −80 ° C. until used for the synthesis of catechol compounds.

(2) Synthesis of catechol compound using transformed microorganism Frozen cells were suspended in phosphate buffer B (pH 7.0) to prepare the following reaction solution (3 ml), and the reaction was started (30 ° C. 300 rpm, 2-24 hours). 2-phenoxyethanol was purchased from Tokyo Chemical Industry.

The reaction solution with a reaction time of 2 hours was analyzed by LC-MS and GC-MS. In the TIC chromatogram, a peak detected only when the substrate was added was confirmed at a retention time of 13.9 minutes. From the product ion, it was confirmed that the peak was 2- (2,3-dihydroxyphenoxy) ethanol. When the reaction solution with a reaction time of 24 hours was analyzed by GC, the concentration of the product was 11.2 mM (1.91 g / L), and the selectivity was 96.6%. The mass spectra for the TIC chromatogram and the peak with a retention time of 13.9 minutes are shown in FIGS. The analytical conditions for LC-MS and GC-MS are as described above. GC analysis conditions and a summary of MS analysis results are shown below.

(GC analysis conditions)
Equipment: GC-2010 (manufactured by Shimadzu Corporation)
Column: DB-17HT (manufactured by Agilent)
Column oven program:

Vaporization chamber temperature: 250 ° C
Injection mode: Split split ratio: 25
Control mode: Linear velocity Linear velocity: 45.1 cm / sec
Pressure: 90.7kPa
Detector temperature (FID): 340 ° C.

The structures of 2-phenoxyethanol used as a substrate and the product catechol compound 2- (2,3-dihydroxyphenoxy) ethanol are shown below.

[Example 3: When IPTG concentration is changed]
(1) Preparation of transformed microorganisms coli BL21 (DE3) / (todA-D / pET21-b (+)) was induced to induce IPTG expression according to the following procedure.

The strain was inoculated into 4 mL of liquid medium A (test tube) and incubated (30 ° C., 300 rpm, overnight, preculture). Subsequently, a preculture was inoculated into liquid medium A (100 ml) so that the initial OD ₆₆₀ was 0.05 (Sakaguchi flask) and incubated (25 ° C., 120 rpm). When OD ₆₆₀ reached 0.4 to 0.5, IPTG (manufactured by Wako Pure Chemical Industries, Ltd.) was added so as to have a final concentration of 10 to 500 μM and incubated (25 ° C., 120 rpm, 24 hours from the start of culture). time). Bacteria were collected and washed with phosphate buffer B (pH 7.0), and stored frozen at −80 ° C. until used for the synthesis of catechol compounds.

(2) Synthesis of catechol compound using transformed microorganism Frozen cells were suspended in phosphate buffer B (pH 7.0) to prepare the following reaction solution (3 ml), and the reaction was started (30 ° C. , 300 rpm, 2-3 hours).

The reaction solution was analyzed by LC-MS, and the catechol compound was quantified from the UV peak. As a result, as shown in the table below, when the IPTG concentration is 5 to 100 μM, particularly 5 to 30 μM, the reaction rate (catechol compound formation rate) is high, and the catechol compound (2- (2,3-dihydroxyphenyl) ) Ethanol) was efficiently produced. The production rate of the catechol compound was the fastest when the IPTG concentration was 10 μM. In the table below, “Initial PEA” is the concentration of 2-phenylethanol in the reaction solution at the start of the reaction solution, and “Conc.” Is the concentration of 2- (2,3-dihydroxyphenyl) ethanol in the reaction solution after the reaction. Refers to concentration. LC-MS analysis conditions are the same as above.

[Example 4: When dissolved oxygen concentration is changed]
(1) Preparation of transformed microorganisms During Sakaguchi flask culture, a large amount of air bubbles is generated, which deteriorates ventilation and decreases the dissolved oxygen concentration in the culture solution. However, since the dissolved oxygen concentration cannot be adjusted in the Sakaguchi flask culture, the influence of the dissolved oxygen concentration on the microorganisms cannot be evaluated. The effect of dissolved oxygen concentration on microorganisms was evaluated, and for further scale-up, E. coli transformed with a jar fermenter was used. coli BL21 (DE3) / (todA-D / pET21-b (+)) was induced to induce IPTG expression according to the following procedure.

Two tubes containing 4 mL of liquid medium A were prepared, inoculated with the strain (test tube), and incubated (30 ° C., 300 rpm, overnight, preculture). Subsequently, the preculture was inoculated into the liquid medium B (1 L) in the 2 L jar fermenter (manufactured by ABLE) so that the initial OD ₆₆₀ was 0.05. Under pH adjustment (2N NaOH was added as necessary so that the lower limit of the pH was 6.0), any of the aeration gases in Table 20 was aerated at an aeration rate of 1 L / min and incubated (25 ° C., 725 rpm).

The aeration gas composition is shown in the table below. In the table below, the gas composition ratio is a volume ratio.

After 4.5 hours from the start of culture, IPTG (manufactured by Wako Pure Chemical Industries, Ltd.) was added so that the final concentration was 10 μM, and cultured at a temperature of 25 ° C. and a stirring speed of 725 rpm for 24 hours.

The culture solution pH, dissolved oxygen concentration (DO), and OD ₆₆₀ values when cultured using the aeration gas are shown in FIGS. 5 to 7 (in the figure, “ppm” is synonymous with “mg / L”). Used in).

The cultured microorganisms were collected and washed with phosphate buffer B (pH 7.0) and then stored frozen at −80 ° C. until use.

(2) Synthesis of catechol compound using transformed microorganisms Frozen cells were suspended in phosphate buffer B (pH 7.0) to prepare the following reaction solution, and the reaction was started (30 ° C., 300 rpm, 4 hours).

At the time of 2 hours (Table 22) or 4 hours (Table 23) from the start of the reaction, the reaction solution was analyzed by LC-MS, and the catechol compound was quantified from the UV peak. As a result, as shown in the table below, air: N ₂ has a 1: 3, 1: 4, or 1: 9 gas as compared to a case where only air or a gas of air: N ₂ = 1: 1 is vented. When aeration was performed, the amount of product catechol compound (2- (2,3-dihydroxyphenyl) ethanol) produced was larger. In the table below, “starting oxygen concentration” is the dissolved oxygen concentration of the reaction solution at the start of the reaction (in the table, “ppm” is used synonymously with “mg / L”), and “initial dissolved oxygen concentration” is The dissolved oxygen concentration in the reaction solution immediately after the addition of IPTG (within 5 minutes), “Initial PEA” is the concentration of 2-phenylethanol in the reaction solution at the start of the reaction solution, “Conc.” Is 2- ( This refers to the concentration of 2,3-dihydroxyphenyl) ethanol in the reaction solution. LC-MS analysis conditions are the same as above. In any test section, the dissolved oxygen concentration did not become higher than the initial oxygen concentration throughout the reaction period.

[Example 5: When substrate is added sequentially]
(1) Preparation of transformed microorganisms coli BL21 (DE3) / (todA-D / pET21-b (+)) was induced to induce IPTG expression according to the following procedure.

The strain was inoculated into 4 mL of liquid medium A (test tube) and incubated (30 ° C., 300 rpm, overnight, preculture). Subsequently, the preculture was inoculated into the liquid medium B (1 L) in the 2 L jar fermenter (manufactured by ABLE) so that the initial OD ₆₆₀ was 0.05. pH adjustment under (as the lower limit of the pH is 6.0, added at any time 2N NaOH), air: _{N 2} is 1: aeration gas is 4 aerated with aeration 1L / min, and incubated (25 ° C. 725 rpm).

After 4.5 hours from the start of culture (OD ₆₆₀ = 0.59), IPTG (manufactured by Wako Pure Chemical Industries, Ltd.) was added so that the final concentration was 10 μM, and the cells were cultured at a temperature of 25 ° C. and a stirring rate of 725 rpm for 24 hours. The cultured microorganisms were collected and washed with phosphate buffer B (pH 7.0) and then stored frozen at −80 ° C. until use.

(2) Synthesis of 2- (2,3-dihydroxyphenyl) ethanol using transformed microorganisms Microbial suspension in which frozen cells were suspended in phosphate buffer B (pH 7.0) to give OD ₆₆₀ = 70 A liquid was prepared. 600 mL of phosphate buffer B, 100 mL of 20% (w / v) aqueous glucose solution, 90 mL of microbial suspension (OD ₆₆₀ = 70), 500 μL of Adecanol® LG-109 (Adeka), and 2.5 g of 2-phenylethanol was added to a 2 L jar fermenter (Able) and incubated (25 ° C., 7 hours, 500 rpm, air 1 vvm).

Subsequently, the frozen cells were suspended in phosphate buffer B (pH 7.0) to prepare a microorganism suspension having an OD ₆₆₀ = 75. An additional 85 mL of microbial suspension (OD ₆₆₀ = 75) and 2.5 g of 2-phenylethanol were added to the above 2 L jar fermenter (Able) and incubated (25 ° C., 14 hours, 500 rpm, Air 1 vvm). The obtained reaction solution (880.5 mL) was analyzed by GC. As a result, 2-phenylethanol was not detected, and 2- (2,3-dihydroxyphenyl) ethanol was 46.5 mM (7.2 g / L). It was confirmed that the product was produced at a rate of 97.0%.

(3) Synthesis of 2- (2,3-dihydroxyphenoxy) ethanol using transformed microorganism Suspended microorganism suspension with OD ₆₆₀ = 124 by suspending frozen cells in phosphate buffer B (pH 7.0) A liquid was prepared. 660 mL of phosphate buffer B, 40 mL of 50% (w / v) aqueous glucose solution, 200 mL of microbial suspension (OD ₆₆₀ = 124), 1 mL of Adecanol® LG-109 (Adeka), and 2.2 g (2 mL) of 2-phenoxyethanol was added to a 2 L jar fermenter (manufactured by ABLE) and incubated (25 ° C., 4 hours, 500 rpm, air 1 vvm).

Subsequently, 200 mL of the microbial suspension (OD ₆₆₀ = 124) and 2.2 g (2 mL) of 2-phenylethanol were additionally added to the 2 L jar fermenter (manufactured by Able) and incubated (25 ° C. 18 hours, 500 rpm, air 1 vvm). The obtained reaction liquid (1105 mL) was analyzed by GC. As a result, 4.2 mM for 2-phenylethanol, 24.3 mM (3.8 g / L) for 2- (2,3-dihydroxyphenoxy) ethanol, and a selectivity of 98 It was confirmed that it was produced at 2%.

[Comparative Example 1: Reaction using Pseudomonas putida F1 strain (ATCC 700007)]
(1) Preparation of microorganism Pseudomonas putida F1 strain (ATCC 700007) was subjected to IPTG expression induction culture according to the following procedure.

The strain was inoculated into 4 mL of LB medium (test tube) and incubated (30 ° C., 300 rpm, overnight, preculture). Subsequently, the preculture was inoculated into an LB medium (100 mL) containing 0.1% toluene so that the initial OD ₆₆₀ was 0.05 (Sakaguchi flask) and incubated (30 ° C., 120 rpm, 24 hours from the start of the culture). time). The cells were collected and washed with phosphate buffer A (pH 7.0), and then stored frozen at −80 ° C. until use.

(2) Synthesis of catechol compound using microorganisms Frozen cells were suspended in phosphate buffer A (pH 7.0), the following reaction solution was prepared, and the reaction was carried out (30 ° C., 300 rpm, 24 hours) ).

The reaction solution was analyzed by LC-MS. As a result, the conversion rate of 2-phenylethanol was 25.1%, but 2- (2,3-dihydroxyphenyl) ethanol, which is a catechol compound, could not be confirmed. In this case, the “conversion rate” is a value represented by the following formula 2.

The main product confirmed was phenylacetic acid (0.77 mM, selectivity 62.1%). This is presumably because 2-phenylethanol was oxidized by alcohol dehydrogenase and the resulting aldehyde was oxidized by aldehyde dehydrogenase. The above estimation does not limit the technical scope of the present invention.

[Comparative Example 2: E.E. reaction using E. coli BL21 (DE3) / pET21-b (+)]
(1) Preparation of transformed microorganism coli BL21 (DE3) / pET21-b (+) was induced to induce IPTG expression according to the following procedure.

The strain was inoculated into 4 mL of LB medium (added with 100 mg / L ampicillin) (test tube) and incubated (30 ° C., 300 rpm, overnight, preculture). Subsequently, a preculture was inoculated into liquid medium A (100 mL) so that the initial OD ₆₆₀ was 0.05 (Sakaguchi flask) and incubated (25 ° C., 120 rpm). When OD ₆₆₀ reached 0.4 to 0.6, IPTG (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the final concentration of 10 μM and incubated (25 ° C., 120 rpm, culture start 24 hours). The cells were collected and washed with phosphate buffer A (pH 7.0), and then stored frozen at −80 ° C. until use.

(2) Synthesis of catechol compound using transformed microorganisms Frozen cells were suspended in phosphate buffer A (pH 7.0), the following reaction solution was prepared, and the reaction was started (30 ° C., 300 rpm). .

The reaction solution was analyzed by LC-MS. The results are shown in Table 26. The conversion rate of 2-phenylethanol at 24 hours from the start of the reaction was 5.4%, but 2- (2,3-dihydroxyphenyl) ethanol, which is a catechol compound, could not be confirmed.

[Example 6: Ratio of the number of copies of cassette (1) to the number of copies of cassette (2)]
(1) Preparation of transformed microorganism According to the above method, a recombinant vector is introduced into the host by the heat shock method or electroporation method in the combinations shown in the table below, and the copy number of cassette (1) is calculated. Each transformed microorganism (IPTG-inducible promoter (1) and IPTG-inducible promoter (2) were both T7 promoters) with different ratios to the copy number of the cassette (2) was prepared. A cassette in the recombinant plasmid introduced into each transformant is schematically shown in FIG. A glycerol stock of the obtained transformed Escherichia coli was prepared and stored at −80 ° C. until preparation of a transformed microorganism described below.

Among the above, strain No. 3 (tod2 + todD strain) is strain no. 2 (tod2 strain) was prepared by introducing the recombinant plasmid todD / pCDF. That is, the tod2 strain was inoculated into 4 ml of LB medium (containing 100 mg / L ampicillin and 1% by mass of glucose), and precultured at 30 ° C. overnight with stirring at 300 rpm. The OD ₆₆₀ of the preculture was measured and found to be 9.05. Next, the preculture solution was inoculated into 100 ml of LB medium (containing 100 mg / L ampicillin and 1% by mass of glucose) so that OD ₆₆₀ was 0.05, and 4.5 hours at 30 ° C. The culture was performed with stirring at 120 rpm. After incubation, centrifugation (7000 rpm, 10 minutes, 4 ° C.) was performed, and the precipitate (bacteria) was collected. 5 ml of 10% by weight glycerol aqueous solution was added to the cells to suspend them, and centrifugation (7000 rpm, 10 minutes, 4 ° C.) was performed to collect precipitates (cells) (washing step). After the washing process was repeated four times in total, the cells were suspended in 2 ml of 10% by mass glycerol aqueous solution. Using the suspension, the recombinant plasmid (todD / pCDF) was obtained from the strain No. in the above table by electroporation. 2 (tod2 strain). The tod2 strain treated with todD / pCDF was inoculated into LB medium (containing 100 mg / L ampicillin, 20 mg / L streptomycin, and 1% by weight glucose), and the transformed strain was selected by antibiotic resistance. Strain No. 3 (tod2 + todD strain) was obtained.

The DNA fragments used for the preparation of each recombinant plasmid are shown in the table below.

The primers and templates used for the synthesis of each of the above DNA fragments are shown in the table below.

E.E. E. coli BL21 (DE3) was purchased from Takara Bio. In addition, pET21-b (Novagen, having a sequence encoding an ampicillin resistance gene) and pCDF Duet-1 (Novagen, having a sequence encoding a streptomycin (Sm) resistance gene) are T7 promoter sequences. Have

(2) Preparation of transformed microorganism Using the above-mentioned tod1, strain 2, tod2 + todD, todD_tod1, and tod2_todD, condition 4 in Example 4 (air: N ₂ = 1: 4, air flow 1 L / min) Then, after 4.5 hours from the start of the culture, a transformed microorganism was prepared in accordance with IPTG added so that the final concentration was 10 μM. In addition, it culture | cultivated by adding 2N NaOH at any time so that the minimum of pH might be set to 6.5.

FIG. 10 shows the dissolved oxygen concentration (DO) of the culture solution when the tod1 strain, tod2 strain, tod2 + todD strain, todD_tod1 strain, and tod2_todD strain were cultured.

(3) Synthesis of a catechol compound using transformed microorganisms 2-phenylethanol (PEA) was used as a raw material in the same manner as in Example 4 except that the cell OD ₆₆₀ at the start of the reaction was changed to 2.5. -(2,3-Dihydroxyphenyl) ethanol (3- (hydroxyethyl) catechol, HEC) was synthesized.

The amount of 2-phenylethanol (PEA) and 2- (2,3-dihydroxyphenyl) ethanol (HEC) in the reaction solution at 2 hours and 4 hours after the start of the reaction was measured by the above method. The selectivity and reaction rate of the catechol compound were determined from the amounts of 2-phenylethanol (PEA) and 2- (2,3-dihydroxyphenyl) ethanol (HEC). The results are shown in FIGS. 11 to 13 and the table below. In the table below, the reaction rate is slightly lower than in Example 4, but this is because the amount of cells used in the reaction is less than in Example 4.

The 2-phenylethanol (PEA) consumption shown in FIG. 11 corresponds to the first half reaction rate in the reaction formula (1). Further, the amount of 2- (2,3-dihydroxyphenyl) ethanol (HEC) produced shown in FIG. 12 corresponds to the reaction rate in the latter half of the reaction formula (1). From FIG. 12, FIG. 13 and the above table, the second half reaction in the reaction formula (1) is promoted by setting the copy number ratio of the cassette (1) and the cassette (2) to 1: 1 to 5: 1. It can be seen that the production rate of the catechol compound is improved and the selectivity is also improved. From FIG. 11, when cassette (1) and cassette (2) are incorporated into the same vector in tandem (todD_tod1 strain, tod2_todD strain), cassette (1) and cassette (2) are incorporated into separate vectors. Compared to the case (tod2 + todD strain), it can be seen that the first half reaction in the reaction formula (1) is promoted.

[Example 7: Types of promoter]
(1) Preparation of transformed microorganism According to the above method, instead of the T7 promoter, a cassette (1) in which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene are operatively linked downstream of the tac promoter is used. A transformed microorganism (tacP-tod1 strain) into which the expression vector was introduced was prepared. A glycerol stock of the obtained transformed Escherichia coli was prepared and stored at −80 ° C. until preparation of a transformed microorganism described below.

The DNA fragments used for the production of the recombinant plasmid are shown in the table below.

E.E. E. coli JM109 was purchased from Takara Bio Inc. In addition, since the promoter of pUC18 (Clontech, which has a sequence encoding an ampicillin resistance gene) is a lac promoter, the expression vector of TacP / pUC18 amplified using a primer containing a tac promoter sequence is used. Constructed. When JM109 was used as the host, cloning was performed according to the protocol of the In-Fusion PCR cloning kit (Takara), and then E. coli was used as the cloning host. E. coli JM109 was used.

(2) Preparation of transformed microorganism Using tacP-tod1 strain, the conditions of Example 3 (Sakaguchi flask, OD ₆₆₀ was adjusted to 0.4 to 0.5 so that the final concentration was 10 to 500 μM) A transformed microorganism was prepared according to (IPTG added).

(3) Synthesis of catechol compound using transformed microorganism According to the method of Example 3, the cell OD ₆₆₀ at the start of the reaction was set to 2.5, and 2-phenylethanol (PEA) was used as a raw material. , 3-Dihydroxyphenyl) ethanol (HEC) was synthesized.

As shown in the table above, when the IPTG concentration is 5 to 100 μM, particularly 15 to 100 μM, the reaction rate (catechol compound formation rate) is high, and the catechol compound (2- (2,3-dihydroxyphenyl) ethanol) It was generated efficiently.

[Composition]
(Composition (1))
From the reaction solution in which 2- (2,3-dihydroxyphenyl) ethanol was synthesized in Example 5 above, 2- (2,3-dihydroxyphenyl) ethanol (catechol compound according to the present invention, 3- (hydroxyl) was synthesized by the following procedure. A composition (1) comprising ethyl) catechol, HEC) and 2- (2-hydroxyphenyl) ethanol (monohydroxide according to the invention) was obtained.

That is, 1 L of the reaction solution was centrifuged (5,000 × g, 30 min, 4 ° C.), the supernatant was collected, and the pH was adjusted to 3 with hydrochloric acid. Thereafter, the supernatant whose pH was adjusted was further centrifuged (5,000 × g, 30 min, 4 ° C.), and the supernatant was collected again, and 100 g of anhydrous sodium sulfate was added. Then, extraction operation was performed twice with 1 L of ethyl acetate. The ethyl acetate phase was dehydrated with anhydrous sodium sulfate, and the solution was filtered with a filter paper (Kiriyama Seisakusho, No. 4). The filtrate was concentrated by a rotary evaporator to obtain a concentrate.

Next, silica gel 60 (manufactured by Merck) was added to the concentrate until the surface of the silica gel was dried, and loaded onto a column packed with silica gel 60. The eluent (ethyl acetate: toluene: acetic acid = 1: 8: 1 (v: v: v)) was passed through the column, and 50 ml each was collected. Part of the sample was developed with TLC (aluminum oxide 150F254 neutral (type T)), and the fraction where no spots were seen other than HEC was filtered with filter paper (Kiriyama Seisakusho, No. 4), and the filtrate was concentrated. After drying, a composition (1) was obtained.

Composition (1) contains 0.13 mol of 2- (2-hydroxyphenyl) ethanol with respect to 100 mol of 2- (2,3-dihydroxyphenyl) ethanol. The contents of 2- (2,3-dihydroxyphenyl) ethanol and 2- (2-hydroxyphenyl) ethanol were confirmed by gas chromatography analysis under the following conditions.

Vaporization chamber temperature: 250 ° C
Injection mode: Split split ratio: 25
Control mode: Linear velocity Linear velocity: 45.1 cm / sec
Pressure: 90.7kPa
Detector temperature (FID): 340 ° C. (internal standard: 5 mM 1-octanol).

(Composition (2))
From the reaction solution in which 2- (2,3-dihydroxyphenoxy) ethanol was synthesized in Example 5 above, 2- (2,3-dihydroxyphenoxy) ethanol (according to the present invention) was produced in the same manner as in composition (1). A composition (2) containing a catechol compound, 3- (hydroxyethoxy) catechol, HEOC) and 2- (2-hydroxyphenoxy) ethanol (monohydroxide according to the present invention) was obtained.

Composition (2) contains 0.78 mol of 2- (2-hydroxyphenoxy) ethanol with respect to 100 mol of 2- (2,3-dihydroxyphenoxy) ethanol. The contents of 2- (2,3-dihydroxyphenoxy) ethanol and 2- (2-hydroxyphenoxy) ethanol were confirmed by the same method as for composition (1).

As shown in FIG. 13, the selectivity of the catechol compound can be adjusted by arbitrarily setting the copy number ratio between the cassette (1) and the cassette (2). The number of moles of the aromatic compound raw material used for the synthesis is M ₁ , the number of moles of the aromatic compound raw material remaining at a certain reaction time is M ₂ , and the dihydroform produced by the first half reaction of the reaction formula (1) When the number of moles of the diol derivative is M ₃ and the number of moles of the produced catechol compound is M ₄ , the relationship of the following formula 3 is established. Note that M ₂ and M _{4 at} an arbitrary reaction time can be measured by arbitrarily combining the above-described measuring methods using LC-MS, GC-MS, and gas chromatography.

The dihydrodiol derivative produced by the first half reaction of the reaction formula (1) is easily dehydrated under acidic conditions to produce a monohydroxide (for example, J Ind Microbiol Biotechnol (2005) 32: 542-547). Therefore, the amount of monohydroxide contained in the composition can be adjusted by arbitrarily setting M ₃ described above.

(Stability evaluation)
HEOC was isolated by further column purification of the above composition (2) twice using a column packed with silica gel 60 (HEOC high-purity product). In the isolated HEOC, it was confirmed that no peaks other than HEOC were detected in the GC analysis described in the column of the composition (1). The composition shown in the following table was prepared by adding 2- (2-hydroxyphenoxy) ethanol (manufactured by Ardrich) to this HEOC high-purity product.

The prepared composition was kept under air at 60 ° C. for 4 days, and the degree of coloring of the composition was observed visually. In addition, the composition was diluted with ethanol so that the total amount of HEOC and monohydroxide was 10 mg / mL, and UV-VIS detector (SPD-20A, manufactured by Shimadzu Corporation) was used for UV- The VIS spectrum was measured. The UV-VIS spectra of the ethanol solution before and after storage are shown in FIGS. 14 and 15, “0 mol”, “0.01 mol”, “0.05 mol” and “1 mol” are the amounts of monohydroxide (moles) per 100 mol of HEOC in each composition. ).

As a result of the storage test, the composition containing the monohydroxide was less colored by visual observation as compared with the HEOC high-purity product not containing the monohydroxide. As for the UV-VIS spectrum, in all the compositions used for the test, the absorbance increased over a wide range after being held at 60 ° C. for 4 days, compared with the spectrum on the 0th day. It can be seen that the increase in absorbance is suppressed by the addition of hydroxide. Among UV-VIS spectra for the _{OD 440} used as an indicator of browning, the composition containing 0.01 mole one hydroxide per 100 moles of HEOC was increased inhibition rate 50.1% . In the table below, the “OD440 increase amount” is obtained by subtracting the OD440 on the 0th day from the value of the OD660 on the 4th day.

(Whitening agent)
B16 melanoma cells were used to evaluate the melanin synthesis inhibitory activity of the composition (1) and the composition (2). Specifically, B16 melanoma cells (purchased from DS Pharma Medical) were seeded in a 6-well plate so that the number of cells was 1 × 10 ⁴ cells / well, and 4 ml of D-MEM medium (DS Pharma Medical) Purchased, 2 mM glutamine (manufactured by Wako Pure Chemical Industries, Ltd.), 10% (w / v) fetal bovine serum (manufactured by AusGeneX), and antibiotics (Penicillin G 100 units / ml, Streptomycin Sulfate 100 μg / ml (both Wako Pure Chemical) Incubated for 24 hours in a 37 ° C. 5% CO ₂ incubator.

Subsequently, the composition (1) or the composition (2) was added to the medium so that the final concentration of the catechol compound according to the present invention was 0.2 mM, and cultured for 48 hours. Thereafter, the medium was changed to a medium containing the same concentration of the catechol compound and cultured for 24 hours. In addition, hydroxytyrosol (2- (3,4-dihydroxyphenyl) ethanol, Tokyo Kasei Kogyo, HT) and kojic acid (Tokyo Kasei Kogyo) were used as comparative objects with known melanin synthesis inhibitory activity (final). Concentration 0.2 mM).

Next, the cells were washed with PBS (−), detached from the plate with 2 ml of a 0.25% (w / v) trypsin / EDTA solution, and the cells were collected with 1 ml of medium. The cell suspension was centrifuged (1,000 × g, 3 min, 4 ° C.) and the supernatant was discarded. Then, 1 ml of phosphate buffer was added to the precipitate and suspended. The number of cells in the suspension was measured with a particle counting analyzer CDA-1000 (manufactured by sysmex). 1 ml of 0.5N sodium hydroxide aqueous solution was added to the cell suspension, and the cells were treated with an ultrasonic disrupter for 2 minutes to disrupt the cells. The protein concentration in the cell lysate was measured by Coomassie Protein Assay Kit (Pierce). In addition, the absorbance at 475 nm (UV-VIS detector (SPD-20A, manufactured by Shimadzu Corporation)) of the cell lysate was measured, and the melanin concentration was measured using a synthetic melanin (Sigma). A line was prepared and quantified, the melanin concentration per protein concentration was calculated, and the melanin synthesis inhibitory activity of each test sample was evaluated, and the results are shown in FIG.

As can be seen from FIG. 16, the composition according to the present invention has a high whitening effect.

The following is an example of whitening agent production.

(Oxygen absorber)
Liquid mixture of glycerin (100 parts by weight), manganese chloride tetrahydrate (6 parts by weight), the above composition (1) or composition (2) (0.05 parts by weight) and pure water (65 parts by weight) Was prepared. This mixed solution was impregnated with calcium hydroxide (500 parts by weight) to obtain an oxygen absorbent. About 200 mg of the above oxygen absorbent was put in a test tube (volume: 62 mL) having an inner diameter of 24 mm and a length of 20 cm, and sealed with a W cap (manufactured by ASONE). After maintaining this at 25 ° C. for 20 or 24 hours, the oxygen concentration in the test tube was measured by the following GC analysis method. As a comparison object, a test group using 0.05 or 0.6 parts by weight of 5-methylresorcin instead of the catechol compound was set.

As a result, the oxygen absorbent containing the composition (1) had an oxygen absorption rate per weight of 0.890 mL-O ₂ / (g · h). The oxygen absorbent containing the composition (2) had an oxygen absorption rate per weight of 0.708 mL-O ₂ / (g · h). The oxygen absorbent containing 0.05 part by weight of 5-methylresorcin had an oxygen absorption rate per weight of 0.291 mL-O ₂ / (g · h). The oxygen absorbent containing 0.6 part by weight of 5-methylresorcin had an oxygen absorption rate per weight of 0.753 mL-O ₂ / (g · h). The results are shown in the table below and FIGS. 17 and 18 (values in the table below, FIGS. 17 and 18 are average values of n = 3).

As described above, it is understood that the oxygen absorbent using the composition according to the present invention exhibits high oxygen absorbability. When compared with 5-methylresorcin, the oxygen absorbent using the composition according to the present invention showed the same level of oxygen absorptivity even with a small addition amount of 1/10 or less.

(GC analysis conditions)
Equipment: GC-2014 (manufactured by Shimadzu Corporation)
Column: Molecular Sieve 13X 6.0m3.00mmID (manufactured by GL Sciences Inc.)
Column temperature: 60 ° C
Detector temperature (TCD): 140 ° C.

This application is based on Japanese Patent Application No. 2014-074406 filed on March 31, 2014, the disclosure of which is incorporated by reference as a whole.

The preparation method of the present invention can be used for synthesizing catechol compounds, and can also be applied to uses such as removal of environmental pollutants by using microorganisms having metabolic properties of catechol compounds as hosts.

[SEQ ID NO: 11]
PCR primer sequence for amplification of todA-D fragment 1.
[SEQ ID NO: 12]
PCR primer sequence for amplification of todA-D fragment 1.
[SEQ ID NO: 13]
PCR primer sequence for amplification of pET21-b (+) fragment.
[SEQ ID NO: 14]
PCR primer sequence for amplification of pET21-b (+) fragment.
[SEQ ID NO: 15]
PCR primer sequence for amplification of pCDF fragment.
[SEQ ID NO: 16]
PCR primer sequence for amplification of pCDF fragment.
[SEQ ID NO: 17]
PCR primer sequence for amplification of todD fragment.
[SEQ ID NO: 18]
PCR primer sequence for amplification of todD fragment.
[SEQ ID NO: 19]
PCR primer sequence for amplification of tod / pET21-b fragment.
[SEQ ID NO: 20]
PCR primer sequence for amplification of tod / pET21-b fragment.
[SEQ ID NO: 21]
Cassette (1) PCR primer sequence for amplification of fragment 1.
[SEQ ID NO: 22]
Cassette (1) PCR primer sequence for amplification of fragment 1.
[SEQ ID NO: 23]
Cassette primer (2) PCR primer sequence for amplification of fragment 1.
[SEQ ID NO: 24]
Cassette primer (2) PCR primer sequence for amplification of fragment 1.
[SEQ ID NO: 25]
PCR primer sequence for amplification of cassette (1) fragment 2.
[SEQ ID NO: 26]
Cassette primer (2) PCR primer sequence for amplification of fragment 2.
[SEQ ID NO: 27]
PCR primer sequence for amplification of todA-D fragment 2.
[SEQ ID NO: 28]
PCR primer sequence for amplification of todA-D fragment 2.
[SEQ ID NO: 29]
PCR primer sequence for amplification of TacP / pUC18 fragment.
[SEQ ID NO: 30]
PCR primer sequence for amplification of TacP / pUC18 fragment.

Claims

A method for preparing a transformed microorganism, comprising culturing a transformed microorganism into which an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene have been introduced in a solution containing 5 to 100 μM isopropyl β-thiogalactopyranoside.
The preparation method according to claim 1, wherein the solution containing isopropyl β-thiogalactopyranoside has a dissolved oxygen concentration of more than 0 mg / L and not more than 5 mg / L.
The preparation method according to claim 1 or 2, wherein the microorganism is Escherichia coli.
The preparation method according to any one of claims 1 to 3, wherein the aromatic ring dioxygenase gene group is a toluene dioxygenase gene group.
The preparation method according to claim 4, wherein the toluene dioxygenase gene group is derived from Pseudomonas putida.
The preparation method according to any one of claims 1 to 5, wherein the aromatic ring dihydrodiol dehydrogenase gene is a cis-toluene dihydrodiol dehydrogenase gene.
The preparation method according to claim 6, wherein the cis-toluene dihydrodiol dehydrogenase gene is derived from Pseudomonas putida.
When the transformed microorganism cultured in the solution containing isopropyl β-thiogalactopyranoside uses 2-phenylethanol as a raw material, 2- (2,3-dihydroxyphenyl) ethanol is 0.45 mM / (h · The preparation method according to any one of claims 1 to 7, which is produced at a rate of OD 660 ) or more.
The transformed microorganism comprises the aromatic ring dioxygenase gene group and the aromatic ring dihydrodiol dehydrogenase gene,
An isopropyl β-thiogalactopyranoside inducible promoter (1) and the aromatic ring dioxygenase gene group operably linked to the promoter (1) and a cassette (1) comprising the aromatic ring dihydrodiol dehydrogenase gene;
An isopropyl β-thiogalactopyranoside inducible promoter (2) and a cassette (2) comprising the aromatic ring dihydrodiol dehydrogenase gene operably linked to the promoter (2),
The preparation method according to any one of claims 1 to 8, wherein the cassette (1) and the cassette (2) are introduced so that a copy number ratio is 1: 1 to 5: 1.
The following general formula (1) using the transformed microorganism prepared by the preparation method according to any one of claims 1 to 9:

In the general formula (1), R is a hydrogen atom, a halogen atom, a phenyl group, a heterocyclic group, or a group represented by the following general formula (2):

In the general formula (2), x is 0 or 1, Y is a linear or branched alkylene group having 1 to 5 carbon atoms, and Z is a hydrogen atom or a hydroxyl group;
The manufacturing method of the catechol compound represented by these.
The production method according to claim 10, wherein the catechol compound is produced by a resting cell reaction.
A transformed microorganism that produces 2- (2,3-dihydroxyphenyl) ethanol at a rate of 0.45 mM / (h · OD 660 ) or more when 2-phenylethanol is used as a raw material.
An isopropyl β-thiogalactopyranoside inducible promoter (1) and a cassette (1) comprising an aromatic ring dioxygenase gene group and an aromatic ring dihydrodiol dehydrogenase gene operably linked to said promoter (1);
An isopropyl β-thiogalactopyranoside inducible promoter (2) and a cassette (2) containing an aromatic ring dihydrodiol dehydrogenase gene operably linked to said promoter (2),
The transformed microorganism according to claim 12, wherein the microorganism is introduced into the microorganism so that the copy number ratio between the cassette (1) and the cassette (2) is 1: 1 to 5: 1.
The transformed microorganism according to claim 13, wherein the promoter (1) and the promoter (2) are T7 promoter or tac promoter.
The following general formula (1):
In the general formula (1), R is a hydrogen atom, a halogen atom, a phenyl group, a heterocyclic group, or a group represented by the following general formula (2):

In the general formula (2), x is 0 or 1, Y is a linear or branched alkylene group having 1 to 5 carbon atoms, and Z is a hydrogen atom or a hydroxyl group;
And a catechol compound represented by the following general formula (3):

In the general formula (3), R ′ is a heterocyclic group or a group represented by the following general formula (4):

In the general formula (4), x ′ is 0 or 1, Y ′ is a linear or branched alkylene group having 1 to 5 carbon atoms, and Z ′ is a hydrogen atom or a hydroxyl group;
Including a monohydroxide represented by
A composition wherein the ratio of the monohydroxide to 100 mol of the catechol compound is 0.002 to 5 mol.
A whitening agent or an oxygen absorbent comprising the composition according to claim 15.