KR101214632B1 - Recombinant Microorganism Producing Taurine and Method for Preparing Taurine Using the Same - Google Patents

Abstract

The present invention relates to a recombinant mutant microorganism having taurine generating ability and a method for producing taurine using the same, and more specifically, a gene encoding acetate kinase, a gene encoding taurine deoxygenase, and 5-glutamyltranspeptide. Taurine in which one or more of the genes encoding Days, the gene encoding the lactate dehydrogenase, and the gene encoding the taurine transporter are weakened or deleted, and the gene encoding the enzyme involved in taurine biosynthesis is introduced. The present invention relates to a recombinant mutant microorganism for production and a method of preparing taurine using the same.
The recombinant mutant microorganism according to the present invention can produce taurine with high efficiency, and thus is useful as an industrially produced microorganism of taurine.

Description

Recombinant Microorganism Producing Taurine and Method for Preparing Taurine Using the Same}

The present invention relates to a recombinant mutant microorganism having taurine generating ability and a method for producing taurine using the same, and more particularly, to a recombinant mutant microorganism having taurine generating ability and a method for producing taurine using the same.

Taurine, or 2-aminoethanesulfonic acid, is a sulfur-containing amine that is present in cells and tissues of mammals, including humans. It is a beta-amino acid whose amino group is attached to the beta-carbon of molecular structure. The low sulfonic acid group is substituted for alpha-carbon, so it is easily ionized even at lower pH than other amino acids. Most of them are not used for protein synthesis and are present in abundance in the form of free amino acids in animal tissues and biological fluids, and are rarely or very small in food tissues. In particular, it is present in high concentrations in organs such as brain, heart, liver and kidney of mammals, skeletal muscle, blood cells, etc., and is present in very high concentration in intracellular fluid as compared to extracellular fluid.

Taurine is biosynthesized from cysteine, a sulfur-containing amino acid, in mammalian tissues and occurs actively in the brain and liver. Biosynthetic pathways known to date are known to have a cysteine sulfonate pathway and a cysteamine pathway. The cysteine sulfonate pathway is known as the major pathway of taurine biosynthesis as the pathway in which hypotaurine produced by the action of cysteine sulfonate dicarboxylase is converted to taurine. The cysteamine pathway is a pathway in which cysteine is converted into cysteamine through several stages of enzymatic reaction and then converted into hypotaurine by the action of cysteamine deoxygenase and then to taurine. The biosynthesis of taurine varies depending on the tissue, but less than about 10% of the total biosynthesis is biosynthesized by the cysteamine pathway, and the activities of cysteine deoxygenase and cysteine sulfonate dicarboxylase show significant differences among animals. There are many differences in taurine's biosynthetic capacity (Sarwar et al., BJN , 79: 129, 1998).

Taurine has been known as a cardiovascular agent because it weakens or deletes the contractile force of the heart when the heart's calcium ion concentration is lower than normal. In addition, it forms polymers with bile acids to relieve the toxicity of bile acids and help the intestines absorb fat, and catecholamines are involved in the breakdown of fatty tissue, promoting fat metabolism, reducing cholesterol and triglycerides to normal blood pressure. It is effective in adult diseases such as arteriosclerosis, hypertension, stroke, and heart failure (Ide T. et. al ., Metabolism : Clinical and Experimental , 51 (9): 1191, 2002).

Cell membranes protect cells by removing peroxides, nitrogen oxides, and free radicals before they damage cell membranes. According to statistics, 5000-6000 tons of taurine is required worldwide, and more than 50% of the produced taurine is used for food and medicine (Tully, PS, Sulfonic Acids.In Kirk-Othmer Encyclopedia of Chemical Technology, John Wiley & Sons, Inc., 2000).

As a method of preparing taurine, which is used for various purposes, there are natural taurine extraction and chemical synthesis. The former method of extracting natural taurine is a method of extracting taurine from mollusks such as squid, octopus and shellfish in which taurine is present in large amounts (Korean Patent Publication No. 10-0058466). It can be used for various purposes such as medicine, but it is very small amount of about 1% compared to all taurine products, and mainly taurine products by chemical synthesis method are used. There are various methods of the latter chemical synthesis method, there may be other impurities in the process of preparing a synthetic taurine, and in particular, inexpensive synthetic taurine can not be used for food.

Accordingly, the present inventors have made intensive efforts to develop microorganisms having taurine high performance to produce taurine by metabolic methods, and as a result, genes encoding acetate kinases and genes encoding taurine deoxygenase that reduce taurine production To prepare a mutant strain attenuated or deleted, and inserting the operon containing the gene encoding the enzyme necessary for the production of taurine into the mutant strain through a recombinant vector, and culturing the taurine with high yield and high productivity It has been confirmed that the present invention has been completed.

An object of the present invention is to provide a recombinant mutant microorganism having a taurine generating ability and a method for producing the same.

Another object of the present invention to provide a method for producing taurine using the recombinant mutant microorganism.

To achieve the above object, the present invention provides a gene encoding acetate kinase, a gene encoding taurine deoxygenase, a gene encoding 5-glutamyltranspeptides, a gene encoding lactate dehydrogenase and Provided are recombinant mutant microorganisms for taurine production, in which one or more of the genes encoding taurine transporters are weakened or deleted, and a gene encoding an enzyme involved in taurine biosynthesis is introduced.

The invention also relates to the ackA gene tauD Gene tauABC gene, ldhA gene, ggt gene is weakened or deleted, pta gene, xsc gene and tpa The present invention provides a recombinant mutant Escherichia coli WADTLG3110 / pTrcTpaXscPta into which a gene is introduced.

The invention also relates to genes encoding acetate kinases, genes encoding taurine deoxygenase, genes encoding 5-glutamyltranspeptides, genes encoding lactate dehydrogenases and taurine transporters in microorganisms. Provides a method for producing a recombinant mutant microorganism for taurine production, characterized in that one or more genes of the gene coding for is weakened or deleted and a gene encoding an enzyme involved in taurine biosynthesis is introduced.

The present invention also provides a method for producing taurine, which comprises culturing the recombinant mutant microorganism to generate taurine, and then recovering taurine from the culture solution.

Recombinant mutant microorganism according to the present invention prepared by using a metabolic engineering method against a microorganism that had no taurine production ability is capable of producing taurine with high efficiency and is useful as an industrially produced microorganism of taurine.

1 is ackA , tauD , tauABC , ldhA from E. coli taurine-producing microorganisms And It shows the metabolic circuit of the mutant microorganism WADTLG3110 which deleted the ggt gene.
Figure 2 shows a genetic map of the recombinant vector pTrcTpa containing the tpa gene.
3 is tpa And The genetic map of the recombinant vector pTrcTpaXsc containing the xsc gene is shown.
4 is tpa , xsc And pta The genetic map of the recombinant vector pTrcTpaXscPta containing the gene is shown.
Figure 5 shows a graph showing the production of taurine in fed-batch fermentation using glucose from WADTLG3110 / pTrcTpaXscPta [(a): microbial growth, acetic acid production and taurine production with incubation time; And (b) changes in lactic acid and glucose with incubation time].

In one aspect, the present invention provides a gene encoding acetate kinase, a gene encoding taurine deoxygenase, a gene encoding 5-glutamyltranspeptides, a gene encoding lactate dehydrogenase, and a taurine transporter. The present invention relates to a recombinant mutant microorganism for producing taurine and a method for producing the same, wherein one or more genes of the gene encoding the scavenger are weakened or deleted, and a gene encoding the enzyme involved in taurine biosynthesis is introduced.

In the present invention, the "weak or deleted gene" refers to the expression of the gene is reduced or lost by manipulating the gene, the activity of the enzyme encoding the gene decreases as the expression of the gene is reduced or lost. Or is deleted and includes all that part or all of the biosynthetic pathway in which the gene is involved is blocked. The genetic manipulation may be to mutate, replace or delete some bases of the gene or to introduce some bases.

The microorganism used in the present invention does not have the ability to produce taurine per se, but the present inventors have been able to produce industrially useful taurine by using a metabolic pathway converted from acetyl-CoA to taurine.

Therefore, the microorganism for producing taurine of the present invention includes a system for converting acetylcoai, which is a starting material of taurine biosynthetic metabolic pathway, through pyruvate metabolic pathway (FIG. 1). Thus, microorganisms containing metabolic pathways that convert to acetylcoay can be used in the present invention without particular limitation. For example, microorganisms using glucose, sucrose, xylose, or the like as a carbon energy source can be appropriately selected and used.

The microorganisms for taurine production that can be used in the present invention include Escherichia sp., Bacillus sp., Corynebacterium sp., And Pichia sp. , there may be mentioned the genus Pseudomonas (Pseudomonas sp.), in my process as Saccharomyces (Saccharomyces sp.) or silica when in bakteo (Silicibacter sp.), ruge Ria in (Ruegeria pomeroyi) and the like. Preferably it may be a genus Bacillus, Escherichia or Silybacter genus, more preferably Escherichia. A representative example may be E. coli. In particular, in the case of E. coli, there is an advantage that can be easily industrialized because the genetic information and culture conditions are known as a strain that is used a lot industrially.

The microorganisms of the present invention are a gene encoding an acetate kinase, a gene encoding taurine deoxygenase, a gene encoding 5-glutamyltranspeptides, a gene encoding lactate dehydrogenase and a taurine transporter If one or more of the genes encoding are attenuated or deleted and contain genes encoding enzymes involved in taurine biosynthesis, these genes may replace taurine precursors derived from acetyl CoA with acetate instead of taurine. The disadvantage is that the conversion or removal of the generated taurine reduces the taurine biosynthesis efficiency.

Thus, genes encoding acetate kinases that degrade taurine biosynthesis efficiency in microorganisms, genes encoding taurine deoxygenase, genes encoding 5-glutamyltranspeptides, genes encoding lactate dehydrogenase, and One or more of the genes encoding taurine transporters was attenuated or deleted to maximize taurine biosynthesis efficiency.

The method of weakening or deleting the gene may be, for example, a homologous recombination method, but is not limited thereto. In one embodiment, ackA (acetate kinase A, AP_002896), a gene encoding acetate kinase, tauD (taurine dioxygenase D, AP_001019), a gene encoding taurine deoxygenase, and 5-glutamyltranspeptides in E. coli The gene encoding ggt (gamma-glutamyltranspeptidase, EC: 2.3.2.2), the gene encoding lactate dehydrogenase ldhA (lactate dehydrogenase A, EC: 1.1.1.28), and the tauABC gene encoding taurine transporter (taurine transporter EC: AP_001016, EC: AP_001017, EC: AP_001018) can be deleted by double-cross homologous recombination.

Contains genes encoding acetate kinases, genes encoding taurine deoxygenase, genes encoding 5-glutamyltranspeptides, genes encoding lactate dehydrogenase, genes encoding taurine transporter In the case of microorganisms present, microorganisms which are attenuated or deleted as described above but which do not contain these genes may be used.

In addition, the recombinant mutant microorganism of the present invention is characterized in that a gene encoding one or more enzymes involved in taurine biosynthesis is introduced. One of the gene encoding the acetate kinase, the gene encoding taurine deoxygenase, the gene encoding 5-glutamyltranspeptides, the gene encoding lactate dehydrogenase, and the gene encoding taurine transporter. The microorganisms in which the above genes are weakened or deleted may be prepared by introducing a gene encoding one or more enzymes involved in taurine biosynthesis, or may be prepared in reverse order.

The gene encoding the taurine biosynthesis enzyme is selected from the group consisting of a gene encoding phosphate acyl convertase, a gene encoding sulfoacetaldehyde acyl convertase, and a gene encoding taurine-pyruvate aminoconvertase. One or more genes. Most preferably, the gene encoding the phosphate acetate acyl convertase, the gene encoding sulfoacetaldehyde acyl convertase, and the gene encoding taurine-pyruvate aminoconvertase are all included.

The gene encoding the phosphate acyl convertase as an enzyme involved in taurine biosynthesis is pta (phosphate acyltransferase, AP_002897) derived from the genus Escherichia. The gene encoding the sulfoacetaldehyde acyl converting enzyme may be xsc (sulforacetaldehyde acyltransferase, YP_168756) derived from the genus Silicibacter or lugeria. In addition, the gene encoding the taurine-pyruvate aminotransferase may be tpa (taurine-pyruvate aminotransferase, YP_165928) derived from the genus Silicibacter or lugeria.

Gene encoding the enzyme involved in taurine biosynthesis can be introduced in the form of a plasmid expression vector containing a strong promoter, the strong promoter is trc promoter, tac promoter, T7 promoter, lactose promoter and trp promoter It may be selected from the group consisting of. The plasmid expression vector containing the strong promoter contains a gene encoding at least one enzyme selected from the group consisting of phosphate acyl convertase, sulfoacetaldehyde acyl convertase and taurine-pyruvate aminoconvertase, It is preferred to contain all of the genes encoding phosphate acyl convertase, sulfoacetaldehyde acyl convertase and taurine-pyruvate aminoconvertase.

For example, the introduction of the gene into E. coli through the electroporation method of the pTrc99a plasmid (Amersham Biosciences, USA) expression vector containing the gene used in the examples can be illustrated.

At this time, the expression regulation of any one of the strong promoter, but is not limited to this may be induced by a substance that induces the activation of a promoter such as lactose. Therefore, the microorganism may be one in which genes for reducing the inhibition of transcription induction by lactose or lactose analogs, preferably genes such as lactose operon repressor, are further weakened or deleted.

In another aspect, the present invention relates to a method for producing taurine, wherein the recombinant mutant microorganism is cultured to generate taurine, and then taurine is recovered from the culture.

In the present invention, the culturing of the recombinant mutant microorganism and recovery of taurine may be carried out using a culture method (batch culture or fed-batch culture) and taurine separation and purification methods commonly known in the conventional fermentation process.

Batch cultivation refers to culturing cells in a reactor that is initially filled with medium and no further nutrient supply or removal. This batch cultivation is used industrially due to its simplicity and advantages in terms of genetic stability. Culture method. Fed-batch cultivation is a cultivation method that is used in fermentation of plant cells or animal cells, which have advantages in terms of productivity and relatively difficult culture conditions in a manner in which nutrients are continuously or semi-continuously supplied.

The method for culturing the recombinant mutant microorganism for taurine production may vary depending on the microorganism used, but in one embodiment, the recombinant mutant Escherichia coli is grown to a late exponential growth period under aeration conditions using a batch fermenter, and the precursor of taurine is Substituting under anaerobic conditions to accumulate acetylcoay, while inducing the expression of enzymes involved in taurine biosynthesis with isotpropyl-beta-D-thiogalactopyranoside (IPTG) may be biosynthesis of taurine.

In the present invention, the biotechnological production of such taurine is intracellular or extracellular ( in vivo or in in vitro ). In one embodiment of the invention in Taurine was produced by the in vivo method. in In vitro , after obtaining a lot of sulfoacetaldehyde, a taurine precursor, the taurin-pyruvate aminotransferase has an extracellular activity under conditions such as temperature and pH. Can be converted to taurine. Such implementations can be made by those skilled in the art as appropriate.

According to the biosynthesis method of taurine using the microorganism of the present invention, not only is it easier to culture than wild-type taurine-producing strains, but also it is possible to produce taurine with high efficiency.

The route for synthesizing taurine from glucose is shown in FIG. 1. As shown in FIG. 1, pyruvate metabolism produces acetylcoay, which is converted to acetyl phosphate, a precursor of taurine, by phosphate acylconvertase, and the acetyl phosphate is converted to an acetyl kinase enzyme. Decompose by Therefore, in the present invention, by reducing or deleting the gene encoding the acetyl kinase enzyme, the taurine precursor is to increase the efficiency of conversion to taurine. Acetyl forstate is also converted to taurine by sulfoacetaldehyde acyl convertase and taurine-pyruvate aminoconvertase, which are easily removed by taurine produced by taurine deoxygenase enzyme and 5-glutamyltrans peptides. do. In addition, the produced taurine is uptake back into the cell by the taurine transporter, which is difficult to recover the final taurine produced. Thus, in the present invention, the recovery efficiency of taurine generated by attenuating or deleting a gene encoding taurine deoxygenase enzyme, 5-glutamyltrans peptidase enzyme, taurine transporter was increased.

That is, the recombinant mutant microorganism of the present invention converts taurine precursors derived from acetyl CoA to acetate instead of taurine to remove the genes encoding acetate kinase, which is an enzyme that decreases the efficiency of taurine biosynthesis, and the resulting taurine. Attenuates or deletes one or more of the genes encoding taurine deoxygenase, 5-glutamyl trans peptides, enzymes that reduce the recovery efficiency of the produced taurine, and deletes the taurine transporter involved in taurine uptake, The gene encoding the enzyme involved in tau biosynthesis may be introduced to improve taurine production ability.

In an embodiment of the present invention, the gene encoding acetate kinase ( ackA ) and the gene encoding taurine deoxygenase ( tauD ), 5-glutamyl transpeptides ( ggt ), lactate dehydrogenase (E. coli) ldhA ), a mutant microorganism that attenuated or deleted the taurine transporter ( tauABC ) was prepared, and an enzyme involved in the taurine biosynthesis was introduced to confirm that the taurine generating ability of the prepared recombinant mutant microorganism was improved under anaerobic conditions.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are for further illustrating the present invention, and the scope of the present invention is not limited to these examples.

In particular, the following examples illustrate only Escherichia sp. Microorganism, which is a taurine-producing microorganism, as a specific vector and a host cell in order to remove the gene according to the present invention, but using different types of vectors and taurine-producing microorganisms. It will also be apparent to those skilled in the art.

Example 1: Preparation of acetyl Koei (acetyl-CoA) genes (tauD) involved in the degradation of the gene (ackA) and taurine (Taurine) encoding acetate kinase, which decompose the inactivated or deleted mutant microorganism

1-1: Preparation of a WA3110 strain with weak or deleted ackA gene

Double-crossover homologous recombination was performed to attenuate or delete the gene ( acA ) coating acetate kinase on the chromosome of E. coli W3110 (ATCC 27325) (Datsenko, KA & Wanner, BL, PNAS , 97). : 6640-6645, 2000). Upstream of the ackA gene using pKD3 (Datsenko, KA & Wanner, BL, PNAS , 97: 6640-6645, 2000) containing a FRT-chloroamphenicol marker (Cm ^R ) -FRT cassette AckA by PCR with primers of SEQ ID NOs: 1 and 2 comprising 50 nucleotides homologous to A FRT-chloroamphenicol marker (Cm ^R ) -FRT cassette was constructed in which the gene was weakened or deleted.

SEQ ID NO: 5`-atgtcgagtaagttagtactggttctgaactgcggtagttcttcactgaagtgta ggctggagctgcttc-3`

SEQ ID NO: 5`-tgccgtgcgcgccgtaacgacggatgccgtgctctttgtacaggttgtaacatat gaatatcctccttag-3`

Datsenko K. et The pKD46 plasmid was constructed with reference to the content described in al (Datsenko KA and Wanner, BL, PNAS 97: 6640, 2000). The pKD46 plasmid was constructed from pBAD18 (L. Guzman Harvard Medical School, Boston) and λ DNA (accession no. J02459) as a template for the γ, β, and exo DNA fragments resulting from PCR reactions. pINT-ts (M. Koob, University of Wisconsin, Madison) was introduced into the plasmid.

The PCR product was electroporated into electrocompetent cells containing the lambda recombinase of the pKD46 plasmid. Colonies containing the mutated strains were treated with Luria-Bertani (LB) agar (Sambrook, J. et. al ., Molecular Cloning: a Laboratory Manual, 3rd edition, Cold Spring Harbor Laboratory Press, 2000). Successful gene replacement of the chloroamphenicol marker (Cm ^R ) was confirmed by direct colony PCR. The antibiotic marker was subsequently removed by a helper plasmid pCP20 (Datsenko, KA & Wanner, BL, PNAS , 97: 6640, 2000), including temperature-sensitive replication origin and IPTG-inducible FLP recombination, resulting in attenuated or ackA genes. The deleted Wa3110 (W3110 Δ ackA ) was prepared.

1-2: ackA and tauD Preparation of strain WAD3110 with weak or deleted genes

Upstream of the tauD gene using pKD3 (Datsenko, KA & Wanner, BL, PNAS , 97: 6640-6645, 2000) containing an FRT-chloroamphenicol marker (Cm ^R ) -FRT cassette as a template FRT-chloro attenuated or deleted the gene ( tauD ) encoding taurine deoxygenase by performing PCR with primers of SEQ ID NOs: 3 and 4 containing 50 nucleotides homologous to Amphenicol Marker (Cm ^R ) -FRT cassette was constructed.

SEQ ID NO: 5`-atgagtgaacgtctgagcattaccccgctggggccgtatatcggcgcaca gtgtaggctggagctgcttc-3`

SEQ ID NO: 5`-acggcgggtttttcgcgaccgcctcgcgccagcgttgatgttcctcctcgcatat gaatatcctccttag-3`

Next, the manufactured purifying the PCR product was, pKD46 by electroporation into E. coli WA3110 (W3110 Δ ackA) containing lambda rikeom TOV-rise (λ recombinase) of plasmid ackA And WAD3110 (W3110 Δ ackA , Δ tauD ) with attenuated or deleted tauD gene was prepared. Colonies containing the mutated strains were selected from Luria-Bertani (LB) agar plates containing chloroamphenicol (Cm; 34 μg / ml), followed by direct colony successful gene replacement of the chloroamphenicol marker (Cm ^R ). It was confirmed by PCR.

1-3: ackA , tauD And tauABC Preparation of WADT3110 Strain with Weakened or Deleted Gene

Upstream of the tauABC gene using pKD3 (Datsenko, KA & Wanner, BL, PNAS , 97: 6640-6645, 2000) containing the FRT-chloroamphenicol marker (Cm ^R ) -FRT cassette as a template FRT-chloroampheny having a weakened or deleted gene ( tauABC ) encoding the taurine transporter by PCR with primers of SEQ ID NOs: 5 and 6 comprising 50 nucleotides homologous to A call marker (Cm ^R ) -FRT cassette was produced.

SEQ ID NO: 5`-atggcaatttcatcgcgtaacacacttcttgccgcactggcattcatcgcTAGGTGACACTATAGAACGCG-3`

SEQ ID NO: 5`-tcattgtacttctccatgccagggcgtcaggcggcgctgtaacgcgcgcaTAGTGGATCTGATGGGTACC-3`

Next, the manufactured purifying the PCR product was, pKD46 by electroporation into E. coli WAD3110 (W3110 Δ ackA, Δ tauD) containing lambda rikeom TOV-rise (λ recombinase) of plasmid ackA, tauD And WADT3110 (W3110 Δ ackA , Δ tauD , Δ tauABC ) with attenuated or deleted tauABC gene was prepared. Colonies containing the mutated strains were selected from Luria-Bertani (LB) agar plates containing chloroamphenicol (Cm; 34 μg / ml), followed by direct colony successful gene replacement of the chloroamphenicol marker (Cm ^R ). It was confirmed by PCR.

1-4: ackA , tauD , tauABC And ldhA Preparation of strain WADTL3110 with weak or deleted genes

Upstream of the ldhA gene using pKD3 (Datsenko, KA & Wanner, BL, PNAS , 97: 6640-6645, 2000) containing a FRT-chloroamphenicol marker (Cm ^R ) -FRT cassette PCR with primers of SEQ ID NOs: 7 and 8 comprising 50 nucleotides homologous to) and downstream, resulting in a weakened or deleted FRT- of the gene coding for lactate dehydrogenase ( ldhA ). A chloroamphenicol marker (Cm ^R ) -FRT cassette was constructed.

SEQ ID NO: 5`- atgaaactcgccgtttatagcacaaaacagtacgacaagaagtacctgcagtgtaggctggagctgcttc-3`

SEQ ID NO: 5`-gttccagcgccgctgcacttggatacggatcgaacgccagcagacgcataCATATGAATATCCTCCTTAG

-3`

Next, the manufactured purifying the PCR product was, by electroporation into E. coli WADT3110 (W3110 Δ ackA, Δ tauD, Δ t auA BC) containing the lambda rikeom TOV-rise (λ recombinase) the pKD46 plasmid ackA, tauD , tauABC And WADTL3110 (W3110 Δ ackA , Δ tauD , Δ tauABC , Δ ldhA ) with attenuated or deleted ldhA gene was prepared. Colonies containing the mutated strains were selected from Luria-Bertani (LB) agar plates containing chloroamphenicol (Cm; 34 μg / ml), followed by direct colony successful gene replacement of the chloroamphenicol marker (Cm ^R ). It was confirmed by PCR.

1-5: ackA , tauD , tauABC , ldhA, and ggt Preparation of WADTLG3110 Strains with Weakened or Deleted Genes

Upstream of the ggt gene using pKD3 (Datsenko, KA & Wanner, BL, PNAS , 97: 6640-6645, 2000) containing a FRT-chloroamphenicol marker (Cm ^R ) -FRT cassette FRT with weakened or deleted gene ( ggt ) encoding 5-glutamyl transpeptides by PCR with primers of SEQ ID NOs: 9 and 10 comprising 50 nucleotides homologous to A chloroamphenicol marker (Cm ^R ) -FRT cassette was constructed.

SEQ ID NO: 5`- atgataaaaccgacgtttttacgccgggtggccattgctgctctgctctcgtgtaggctggagctgcttc-3`

SEQ ID NO: 10`-taacgataaaaccatcgcgtgccagtttaaacgcgggctgcacgactttgCATATGAATATCCTCCTTAG

-3`

Next, the purified PCR product was purified and then electroporated to E. coli WADTL3110 (W3110 Δ ackA , Δ tauD , Δ t auA BC, Δ ldhA ) containing lambda recombinase of pKD46 plasmid. WADTLG3110 (W3110 Δ ackA , Δ tauD , Δ tauABC , Δ ldhA , Δ ggt ) with ackA , tauD , tauABC , ldhA and ggt genes were prepared. Colonies containing the mutated strains were selected from Luria-Bertani (LB) agar plates containing chloroamphenicol (Cm; 34 μg / ml), followed by direct colony successful gene replacement of the chloroamphenicol marker (Cm ^R ). It was confirmed by PCR.

Example  2: Construction of recombinant vector (pTrcTpaXscPta) containing genes involved in taurine biosynthesis

2-1: Construction of Plasmid pTrcTpa

Silicibacter The genomic DNA of pomeroyi was used as a template, and PCR was performed using the primers of SEQ ID NOs: 11 and 12 to prepare a tpa gene fragment encoding taurine-pyruvate aminotransferase.

SEQ ID NO: 5`-tataggatccacacaggaaacagaccatggacggcacgttcaacg a-3`

SEQ ID NO: 12: 5`-aagcttctagccgaagacgcgggtc a-3`

Next, a restriction enzyme ( BamHI ) was added to the pTrc99a plasmid (Phamacia, Biotech, Uppsala, Sweden) that proceeds with strong gene expression of the prepared tpa fragment and trc promoter. And HindIII ), followed by treatment with T4 DNA ligase to conjugate the tpa fragment and pTrc99a plasmid digested with restriction enzymes, thereby producing a high copy number recombinant plasmid pTrcTpa (FIG. 2). .

2-2: Construction of the plasmid pTrcTpaXsc

Silicibacter The genomic DNA of pomeroyi was used as a template, and PCR was performed using the primers of SEQ ID NOs: 13 and 14 to prepare an xsc gene fragment encoding a sulfoacetaldehyde acyltransferase .

SEQ ID NO: 5`-gtccgaattcatggagtgcgtactcatgaa-3`

SEQ ID NO: 14`-tattggtacctcagacctgctgttcgcgca-3`

Next, the prepared xsc fragment and Silicibacter After treatment with the restriction enzymes ( EcoRI and KpnI ) to the pTrc99a plasmid containing taurine-pyruvate aminotransferase encoding the Tpa of pomeroyi and undergoing strong gene expression of the trc promoter, T4 DNA ligue Ise was processed to conjugate the xsc fragment digested with the restriction enzyme and the pTrcTpa plasmid to prepare pTrcTpaXsc, a high copy number recombinant plasmid (FIG. 3).

2-3: Construction of the plasmid pTrcTpaXscPta

Silicibacter pta encoding the phosphate acyltransferase by PCR with the primers of SEQ ID NOs: 15 and 16, using genomic DNA of pomeroyi as a template Gene fragments were prepared.

SEQ ID NO: 15`-tataggtaccacacaggaaacagaccgtgtcccgtattattatgct-3`

SEQ ID NO: 5`-tattggtaccttactgctgctgtgcagact-3`

Next, the prepared pta fragment and Silicibacter Silicibacter and the xsc gene encoding pomeroyi's sulfoacetaldehyde acyltransferase tpa encoding taurine-pyruvate aminotransferase from pomeroyi The pTrcTpaXsc plasmid containing the gene and undergoing strong gene expression of the trc promoter was treated with a restriction enzyme ( KpnI ) and then treated with a T4 DNA ligase, thereby conjugating the pta fragment and pTrcTpaXsc plasmid digested with the restriction enzyme to obtain a replication rate. This high copy number recombinant plasmid pTrcTpaXscPta was constructed (FIG. 4).

Example  3: WADTLG3110 Of pTrcTpaXscPta  Preparation of the strain

Embodiment the ackA, tauD, tauABC, ldhA prepared in Example 1 And WADTLG3110 / pTrcTpaXscPta by introducing the pTrcTpaXscPta vector prepared in Example 2 to the WADTLG3110 mutant strain lacking the ggt gene Strains were prepared (electroporation at 2.5 kV, 25 μF, 200 ohms). Next, mutant microorganisms recombined with pTrcTpaXscPta vector were selected while culturing the prepared strains in agar solid medium containing ampicillin.

Example  4: WADTLG3110 Of pTrcTpaXscPta  Strain Oil price  Preparation of Taurine by Culture

Subjected to recombinant mutant strain with the production WADTLG3110 / pTrcTpaXscPta in Example _{3 4g / L (NH 4)} 2 HPO 4, 13.5g / L KH 2 PO 4, 1.7g / L citric acid, 0.7g / L MgSO 4? 7H 2 Shake culture was carried out using a flask in a minimum R medium (Lee, SY & Chang, HN, Biotechnol . Lett., 15: 971, 1993) consisting of O, 0.5% (v / v) trace element solution. The trace elements solution per liter of _{5M HCl, 10g FeSO 4? 7H} 2 O, 2.25g ZnSO 4? 7H 2 O, 1g CuSO 4? 5H 2 O, 0.5g MnSO 4? 5H 2 O, 0.23g Na 2 B 4 _{O 7?? 10H 2 O,} 2g CaCl 2 comprises 2H ₂ O, and _{0.1g (NH 4) 6 Mo 7} O 24. The glucose (100 g / L) stock solution was sterilized separately and added to the sterilized medium to a final concentration of 10 g / L. In LB medium, 1 ml of WADTLG3110 / pTrcTpaXscPta culture was added to a 350 ml baffled flask containing 50 ml of the same medium, followed by incubation at 37 ° C. and 220 rpm for 24 hours until the OD ₆₀₀ value was 2. Next, the strain recombined with WADTLG3110 / pTrcTpaXscPta was subjected to a 6.6 liter fermenter (Bioflo 3000; New Brunswick Scientific) without inducing the expression of a gene encoding an enzyme involved in taurine biosynthesis under aeration conditions for culturing to a concentration for biosynthesis of taurine. Co., Edison, NJ) was inoculated with 2 L of the new culture medium of the same composition to maintain the pH at 6.8 using 850 rpm, 40% saturated air and 28% (v / v) ammonia solution. Culture was performed until the OD ₆₀₀ value was 2 in miracle culture conditions. Simultaneously, 0.1 mM IPTG expresses a gene encoding phosphate acyl convertase ( pta ), a sulfoacetaldehyde acyl converting enzyme ( xsc ) and a taurine-pyruvate amino converting enzyme ( tpa ). After the sample was taken at 1 or 2 hour intervals, the cells were separated by centrifugation and the supernatant was analyzed by HPLC.

As a result, little taurine was produced in the wild type W3110 wild type (control 1). In other words, analysis of taurine production in wild-type showed little production and no detection on HPLC.

As shown in Figure 5, after increasing the cell volume for 25 hours incubation and induction of taurine biosynthesis by adding IPTG, the taurine content in the culture medium gradually increased to produce about 8.01 g / L taurine for 25 hours Confirmed.

In addition, even when the growth of the strain is stopped, the increase in glucose consumption is estimated to be consumed as glucose is converted to taurine through acetylcoei and converted to lactic acid through lactic acid fermentation.

From these results, it can be seen that using E. coli W3110, which had no taurine generating ability, taurine can be produced with high efficiency by knocking out ackA , tauD , tauABC , ldhA and ggt and introducing genes involved in taurine biosynthesis.

As described above in detail specific parts of the present invention, it is apparent to those skilled in the art that such specific descriptions are merely preferred embodiments, and thus the scope of the present invention is not limited thereto. something to do. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

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Claims (17)

In microorganisms including metabolic circuits using acetylcoei, phosphate acyltransferase, sulfoacetaldehyde acyltransferase and taurine-pyru, genes encoding enzymes involved in taurine biosynthesis Taurine-pyruvate aminotransferase is introduced, gene encoding acetate kinase, gene encoding taurine dioxygenase, 5-glutamyltranspeptides (gamma) A recombinant mutant microorganism for taurine production, wherein the gene encoding -glutamyltranspeptidase, the gene encoding lactate dehydrogenase, and the gene encoding taurine transporter are weakened or deleted.
delete The method of claim 1, wherein the microorganism is selected from the group consisting of the genus Escherichia, Bacillus, Corynebacterium, Peachia, Pseudomonas, Saccharomyces and Silicibacter. Recombinant mutant microorganism for taurine production.
4. The recombinant mutant microorganism for producing taurine according to claim 3, wherein the microorganism is genus Escherichia.
The recombinant mutant microorganism for taurine production according to claim 4, wherein the microorganism is Escherichia coli.
The method of claim 1, wherein the gene encoding the acetate kinase is ackA , the gene encoding the taurine deoxygenase is tauD , the gene encoding the taurine transporter is tauABC , and the lactate dehydrogenase is encoded. The gene is ldhA, and the gene encoding 5-glutamyl transpeptides is ggt .
delete According to claim 1, wherein the gene encoding the phosphate acyl convertase, sulfoacetaldehyde acyl convertase and taurine-pyruvate aminoconvertase is a recombinant mutation for generating taurine, characterized in that each derived from the genus silicibacter microbe.
The recombinant mutant microorganism for producing taurine according to claim 1, wherein the gene encoding lactose operon repressor ( lacI ) is further weakened or deleted.
ackA gene tauD Gene tauABC gene, ldhA gene, ggt gene is weakened or deleted, pta gene, xsc gene and tpa Recombinant mutant E. coli WADTLG3110 / pTrcTpaXscPta.
In microorganisms including metabolic circuits using acetylcoei, genes encoding acetate kinases, genes encoding taurine deoxygenase, genes encoding 5-glutamyltranspeptides, lactate dehydrogenases Attenuates or deletes the gene encoding the taurine transporter, phosphate acyltransferase, a sulfoacetaldehyde acyltransferase, a gene encoding an enzyme involved in taurine biosynthesis. And Taurine-pyruvate aminotransferase (taurine-pyruvate aminotransferase) method for producing a recombinant mutant microorganism for producing taurine, characterized in that the introduction.
The method of claim 11, wherein the gene encoding the enzyme involved in taurine biosynthesis is introduced by a vector containing a promoter selected from the group consisting of trc promoter, tac promoter, T7 promoter, lactose promoter and trp promoter Method for producing a recombinant mutant microorganism for producing taurine.
delete 12. The method of claim 11, wherein the gene encoding lactose operon repressor ( lacI ) is further weakened or deleted.
The method of claim 12, wherein the vector has a sequence map of Figure 4, pta gene, xsc gene and tpa Method for producing a recombinant mutant microorganism for producing taurine, characterized in that it contains all the genes.
Method for preparing taurine comprising the following steps:
(a) culturing the recombinant mutant microorganism of any one of claims 1, 3 to 6 and 8 to 10 to produce taurine; And
(b) recovering the generated taurine. Method for preparing taurine comprising the following steps:
(a) culturing the recombinant variant E. coli WADTLG3110 / pTrcTpaXscPta of claim 10 to produce taurine; And
(b) recovering the generated taurine.

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