KR20180076414A - Novel Bacillus subtilis BSM-KO2 having improved menaquinone-7 productivity and method for mass production of menaquinone-7 by using thereof - Google Patents

Abstract

The present invention relates to a Bacillus subtillis BSM-K02 mutant strain (KCTC13028BP) having menaquinone-7 (MK-7) productivity, and a method for mass-producing menaquinone-7 using the same. More specifically, the present invention relates to a method for mass-producing menaquinone-7 under an optimized culture medium and culture conditions by using a mutant strain. The method induces mutation by treating a strain of Bacillus subtillis sp. with ultraviolet rays (UV) or nitrosoguanidine (NTG), selects a mutant strain which has resistance against menadione from the strain and which does not receive inhibition against aromatic amino acid, and mass-produces menaquinone-7 under an optimized culture medium and culture conditions by using the selected Bacillus subtillis BSM-K02 mutant (KCTC13028BP). The new strain Bacillus subtillis BSM-K02 mutant strain of the present invention has excellent productivity of vitamin K2, that is, menaquinone-7, can mass-produce menaquinone-7 from the strain under the optimized culture medium and culture conditions according to the present invention, and can remarkably reduce production costs of menaquinone-7.

Description

A novel strain Bacillus subtilis BSM-K02 with improved menaquinone-7 productivity and a method for mass-producing menaquinone-7 using the same. using them}

The present invention relates to a menaquinone -7 (MK-7) Bacillus subtilis (Bacillus subtillis) BSM-K02 mutant strain (KCTC13028BP) and mass production method of menaquinone -7 using the same having a producing ability. More particularly, the genus Bacillus subtilis (UV) or NTG (nitrosoguanidine) to a mutant to induce a mutation in the strain, which is resistant to menadione and is not inhibited by an aromatic amino acid selecting a strain, and to a method for the culture medium and under culture conditions optimized by the selection of Bacillus subtilis (Bacillus subtillis) BSM-K02 mutant strain (KCTC13028BP) mass production of menaquinone -7.

Vitamin K is a fat-soluble vitamin with a napthoquinone ring structure. Two kinds of vitamins K1 (phylloquinone) and vitamin K2 (menaquinone) can be obtained from natural sources. Specifically, vitamin K1 can be obtained from plants, and vitamin K2 can be obtained from microorganisms. These vitamin K2 can be divided into menaquinone-1 to menaquinone-14 depending on the isoprenyl side chain length attached to naphthoquinone, and commercially available menaquinone-4 (menaquinone-4) and menaquinone-7 (menaquinone-7). Menaquinone-7 is produced by microbial production and chemical synthesis. In the case of producing menaquinone-7 by chemical synthesis, trans-form and isomer cis-form exist in a side chain isoprenyl unit, In the case of production of mannanquinone-7 as a microorganism, it is an all-trans-form structure in which an isoprenyl unit does not have a cis-form. The structural difference of these side chains affects the absorption rate and bioactivity of menaquinone-7, and the absorption rate and bioactivity of menaquinone-7 produced from microorganisms are lower than those of menaquinone-7 produced by chemical synthesis. Is known to be high.

Such vitamin K is known to be an important factor for synthesizing glutamate of Gla-protein as gamma-carboxyglutamic acid (MJ Shearer, British J. Haemaltol . , 75 (2): 156-162, 1990). In particular, vitamin K2, namely menaquinone-7, promotes osteoblast formation, reduces osteoclast, helps osteoblastgenesis, and prevents osteoclastogenesis. In addition, it has been used for the prevention of calcium hardening in blood vessels, bone fracture prevention and osteoporosis prevention by activating osteocalcin and matrix Gla protein (martrix Gla protein, MGP), which are special proteins for calcium in the body, (Y Koshihara et. al, J. Endocrinol, 176 (3 ): 339-348, 2003; Cranenburg ECM et.al., J. Vasc Res, 45 (5):.... 427-436, 2008).

Recently, osteoporosis diseases such as fractures are increasing as the population of elderly people is increasing, and the socioeconomic costs are increasing. In order to prevent this, supplementation with hormones and vitamin D and K2 are recommended, but the amount of vitamin K2 that can be consumed in meat, eggs, fermented food, etc. is minimal (Korean Patent No. 10-1196338). Natto, a traditional Japanese food, contains 800 to 900 μg of menaquinone-7 per 100 g of NATO, making it the most abundant food with menaquinone-7 (MD Collins et al . , Micobiol . Mol . Bio. Rev. , 45 (2): 316-354, 1981). However, many people are unfamiliar with NATO intake and are currently taking vitamin K2 in amounts less than the recommended daily intake of 1 μg / kg (body weight) / day recommended in the US (Sarah L. Booth et al .., J. Nutr, 128 ( 5): 785-788, 1998). For this reason, many health newsletters encourage the ingestion of fermented products produced by microorganisms, and many companies in the West also sell vitamin K2-containing products.

Vitamin K2 production strains to date Flavobacterium (Flavobacterium), Lactobacillus (Lactobacillus), propionic sludge bacteria (Propionibacteria), Lactococcus (Lactococcus), current Kono Stock (Leuconosto c), Bacillus (Bacillus), etc. are known , And the kinds of vitamin K2 that each microorganism mainly produces vary. Bacillus subtilis in scan of Bacillus (Bacillus) of the above microorganisms (Bacillus subtilis sp.) Are known to produce mainly menaquinone -7 vitamin K2. Particularly, 90 to 96% of the vitamin K2 produced by the microorganism is menaquinone-7 (Korean Patent No. 10-1196338). Thus, studies on the production of menaquinone-7 of vitamin K2 have been carried out mainly using Bacillus sp., And the strain of Bacillus subtillis natto has been found to contain vitamin K2, namely menaquinone- 7 is known to produce many.

Biosynthetic pathway of menaquinone -7 has been shown by studies with Escherichia coli (E. coli) and Bacillus subtilis (Bacillus subtillis). Menaquinone-7 biosynthesis is a reaction between 1,4-Dihydroxy-2-naphthoic acid (DHNA) produced in a metabolic circuit to make a quinone skeleton, Polyprenyl pyrophosphate made from metabolic circuits that make isoprene units is made by combining with isoprene units in DHNA by heptaprenyl diphosphate (HDP) synthase (Sato T. et al. , J. Biosci . Bioeng . , 91 (1): 16-20, 2001). The heptaprenyl diphosphate (HDP) synthase is composed of two components, and when component I is combined with component II, the quinone skeleton ) Is bonded to an isoprene unit (isoprene unit). On the other hand, when the concentration of L-phenylalanine, L-tryptophan, and L-tyrosine, which are aromatic amino acids in the medium, is high, the production of quinone skeleton is inhibited (Y. Tsukamoto et al ., Biosci . Biotechnol . Biochem . , 65 (9): 2007-2015, 2001). It is known that menaquinone-7 acts as an oxidation-reduction reaction product in an electron transport system or an oxidative phosphorylation process and constitutes a bacterial plasma membrane (Rowland B. et al. , Gene , 167 (1-2): 105-109, 1995).

Studies on the production of vitamin K2, namely menaquinone-7 using the genus Bacillus subtilis sp., Have been carried out by mutating the strain of Bacillus subtilis natto, It is done through stationary culture. However, studies on the production of menaquinone-7 by liquid culture using Bacillus subtilis sp. Strain have been hardly known.

Sato et al. Reported that Bacillus subtilis natto MH-1, a menadione-resistant mutant of Bacillus subtilis K3-176 , isolated from natto, (Menaquinone-7, MK-7) of 35 ㎎ / ℓ were obtained by culturing in a medium containing 10% soybean extract, 5% glycerine and 0.5% yeast extract for 120 hours, Was 0.29 mg / l per hour (hr). The specific productivity per unit cell of the strain was 10 mg-MK7 / g-cell (T Sato et al ., J. Ind . Microbiol . Biotech. , 26 (3): 115-120, 2001).

In addition, the mogyun, NATO Bacillus subtilis (Bacillus subtillis natto) 0.05% of diphenyl amines (diphenylamine) resistance mutations own, Bacillus subtilis (Bacillus subtillis) D200-41 obtained from the MH-1 in the same medium and the second And cultured for another 120 hours to obtain 60 mg / l of menaquinone-7 (MK-7). The cultured cells were cultured for 24 hours in the presence of potassium phosphate (Dibasic; K ₂ HPO ₄ ) , And productivity was 0.41 mg / l per hour (T Sato et al ., J. Biosci. Bioeng . , 91 (1): 16-20, 2001).

Bacillus subtilis natto isolates from natto were fermented with 5% yeast extract, 5% glycerine, 18.9% soybean peptone, 0.06% potassium phosphate dibasic K ₂ HPO ₄₎ and 120 hours from the culture medium 226 ㎎ / ℓ menaquinone -7 (menaquinone-7, MK- 7 in; have gained vitamin K2), productivity (productivity) is 1.8 ㎎ / ℓ per hour (hr) . The specific productivity per unit cell, which is the ability to produce menaquinone-7, was 16 mg-MK7 / g-cell (Aydin Berenjian et al . , Appl . Biochem . Biotech. : 1347-1357, 2014).

Puri et al . Reported that Bacillus subtilis MTCC 2756 was cultivated in a medium containing 10% soybean flour, 0.5% yeast extract, 0.05% potassium phosphate dibasic (K ₂ HPO ₄ ), and 5% glycerine 1-naphthol and tween 80, which are precursors of menaquinone-7 (MK-7; vitamin K2), were grown in the medium at a concentration of 0.2% And 0.1%. After the addition, the culture was further cultured for 8 hours to obtain 14.4 mg / l of menaquinone-7, MK-7 (vitamin K2), and the productivity was 0.6 mg / l per hour (A. Puri et al ., Songklanakarin J. Sci. Technol. , 37 (3): 283-289, 2015).

The production of vitamin K2, namely menaquinone-7 and MK-7 as described above, is mainly performed by a strain of Bacillus subtilis natto isolated from natto, There is a difficulty in commercial production because the concentration of organic nitrogen source is high and the fermentation time is long and the production cost is high and the productivity is low. In addition, although mutation of the Bacillus subtilis strain may shorten the fermentation time and reduce the concentration of organic nitrogen, the concentration of menaquinone-7 is low, which limits its application to commercial production.

Under these circumstances, the inventors of the present invention selected a strain of the new strain Bacillus subtilis BSM-K02 with improved vitamin K2, i.e., the ability to produce menaquinone-7, and cultivated in a culture medium optimized for producing menaquinone- Thereby completing the present invention.

Korean Patent No. 10-1196338

MJ Shearer, British J. Haemaltol., 75 (2): 156-162, 1990 Y Koshihara et al., J. Endocrinol., 176 (3): 339-348, 2003 Cranenburg E.C.M. et al., J. Vasc. Res., 45 (5): 427-436, 2008 MD Collins et al., Micobiol. Mol. Bio. Rev., 45 (2): 316-354, 1981 Sarah L. Booth et al., J. Nutr., 128 (5): 785-788, 1998 Sato T. et al., J. Biosci. Bioeng., 91 (1): 16-20, 2001 Y. Tsukamoto. et al., Biosci. Biotechnol. Biochem., 65 (9): 2007-2015, 2001 Rowland B. et al., Gene, 167 (1-2): 105-109, 1995 T Sato. et. al., J. Ind. Microbiol. Biotech., 26 (3): 115-120, 2001 T Sato. et al., J. Biosci. Bioeng., 91 (1): 16-20, 2001 Aydin Berenjian et al., Appl. Biochem. Biotech., 172 (3): 1347-1357, 2014 A. Puri. et al., Songklanakarin. J. Sci. Technol., 37 (3): 283-289, 2015

An object of the present invention to provide menaquinone -7 (MK-7) Bacillus subtilis (Bacillus subtillis) BSM-K02 mutant strain (KCTC13028BP) having a producing ability.

Yet another object of the present invention is to provide a method for mass production of menaquinone-7 (MK-7) comprising culturing the Bacillus subtilis BSM-K02 mutant strain (KCTC13028BP).

In order to achieve the above object, the present invention provides a mutant strain of BSM-K02 ( Bacillus subtillis ) having the ability to produce menaquinone-7 (MK-7) as a vitamin K2 and a strain of menaquinone- 7 < / RTI > (MK-7).

Hereinafter, the present invention will be described in detail.

In some embodiments, the invention provides a vitamin K2 menaquinone -7 (MK-7) Bacillus subtilis (Bacillus subtillis) BSM-K02 mutant strain (KCTC13028BP) having a producing ability.

The Bacillus subtilis (Bacillus subtillis) BSM-K02 mutant strain (KCTC13028BP) is an ultraviolet (UV) or NTG (nitrosoguanidine) treatment to induce mutation, and the resistance, and a high concentration of aromatic amino acids to menadione (menadione) (aromatic amino acid is not inhibited by vitamin K2 production by the Bacillus subtilis mutant strain.

The new strain Bacillus subtillis BSM-K02 was deposited on May 25, 2016 with the deposit number KCTC13028BP at the Korea Research Institute of Bioscience and has excellent vitamin K2, namely, menaquinone-7 (MK-7) .

In one embodiment of the present invention, an ultraviolet (UV) or NTG (nitrosoguanidine) in the Bacillus subtilis (Bacillus subtillis) BSM-K02 mutant strain (KCTC13028BP) is Bacillus subtilis (Bacillus subtillis) BSM-Control strain Which is resistant to menadione and is not inhibited by an aromatic amino acid. The present invention relates to a method for producing a vitamin K2, namely, menaquinone-7 ( MK-7) was superior to that of the parent strain Bacillus subtillis BSM-Control (FIGS. 3 and 4).

The vitamin K3 "menadione" is a quinone skeleton structure that is the head part of menaquinone-7 (MK-7), a vitamin K2, and has a high concentration of menadione The strains with resistance to HCV can be expected as strains which are not inhibited by various factors during the production of large quantities of quinone skeleton.

The mutant strains resistant to menadione can be screened by treating menadione at a concentration of 5 to 20 ppm, preferably 15 ppm, although not limited thereto.

The "aromatic amino acid" may be, but is not limited to, L-tyrosine, L-tryptophan, L-phenylalanine, If the concentration of amino acid is high, the production of vitamin K2, quinone skeleton which is the head part of menaquinone-7, may be inhibited.

The mutant strain in which the production of vitamin K2 by the aromatic amino acid is not inhibited is preferably L-tyrosine at a concentration of 100 to 150 ppm, preferably 125 ppm, preferably 50 to 100 ppm, Can be selected by treating L-tryptophan at a concentration of 62.5 ppm with L-phenylalanine at a concentration of 50 to 100 ppm, preferably 62.5 ppm, but is not limited thereto.

In one embodiment of the present invention, Bacillus subtilis (Bacillus subtillis) after the mutagenic process the ultraviolet (UV) or NTG (nitrosoguanidine) in the BSM-Control, menadione TGY agar medium containing (menadione) containing Resistant L-tyrosine, L-tryptophan, and L-tryptophan grown in a culture medium (1% tryptone, 0.5% yeast extract, 0.5% sodium chloride (NaCl), pH 7.0) ( Bacillus subtilis ) BSM-K02 mutant strain (KCTC13028BP) having excellent vitamin K2, ie, menaquinone-7 production ability, was selected by inoculation on TGY medium containing L-phenylalanine Table 1).

In yet another aspect, the present invention provides a method for the mass production of menaquinone-7 (MK-7) comprising culturing a Bacillus subtilis BSM-K02 mutant strain (KCTC13028BP).

The strain may be cultured in a medium containing a carbon source, an organic nitrogen source and an inorganic nitrogen source.

The medium contains sucrose as a carbon source, yeast extract as an organic substance, ammonium sulfate ((NH ₄ ) ₂ SO _{4 )} , potassium monophosphate (K ₂ HPO ₄ ) and magnesium sulfate (MgSO ₄ ) , And a medium containing calcium chloride (CaCl ₂ ) and manganese sulfate (MnSO ₄ .H ₂ O) as other salts. Specifically, the medium may contain sucrose, which is a carbon source, and yeast extract as an organic substance, in a weight ratio of 1: 0.1 to 0.5, and may be contained at a weight ratio of 1: 0.3, though not limited thereto. In addition, sucrose as a carbon source and ammonium sulfate ((NH ₄ ) ₂ SO ₄ ) as an inorganic substance may be contained in a weight ratio of 1: 0.06 to 0.33, and may be contained at a weight ratio of 1: 0.06, although not limited thereto. The sucrose as a carbon source and potassium monophosphate (K ₂ HPO ₄ ) as an inorganic substance may be contained in a weight ratio of 1: 0.016 to 0.050, and may be contained at a weight ratio of 1: 0.05, though not limited thereto. On the other hand, sucrose as a carbon source and magnesium sulfate (MgSO ₄ ) as an inorganic substance may be contained in a weight ratio of 1: 0.016 to 0.080, and may be contained at a weight ratio of 1: 0.016, although not limited thereto.

The medium may be an optimized medium capable of increasing the productivity of vitamin K2, i.e. menaquinone-7, from the Bacillus subtilis BSM-K02 mutant strain (KCTC13028BP).

The culture may be performed at a culture temperature of 39 to 44 DEG C, aeration rate of 0.1 to 1 vvm, and a stirring speed of 400 to 1,100 rpm, without pH adjustment during cultivation, though not limited thereto. Specifically, the incubation temperature may be 43 ° C, the aeration rate may be 0.5 vvm, and the stirring speed may be 600 rpm. If the temperature is outside of the above-mentioned culture temperature, a problem may arise in the growth of the microorganism. If the microorganism is out of the range of the aeration rate and stirring speed, the viscosity of the culture medium may increase due to the production of the polymer.

The culture is characterized in that the pH is not controlled during the course of culturing. The 'no pH control' is performed at an initial pH of 6.4 to 6.8 when the Bacillus subtilis BSM-K02 mutant strain (KCTC13028BP) (HCl) or caustic soda (NaOH) treatment for this pH change during incubation. The pH of the culture is decreased from 5.5 to 6.0 during the incubation, It means to leave it as it is without it.

In one embodiment of the present invention there is provided a pharmaceutical composition comprising sucrose, yeast extract, ammonium sulphate ((NH ₄ ) ₂ SO ₄₎ , potassium monophosphate (K ₂ HPO ₄ ) and magnesium sulfate (MgSO ₄ ) ( Bacillus subtilis ) BSM-K02 mutant strain (KCTC13028BP), the culture temperature was changed from 37 ° C at the initial 37 ° C to 43 ° C the production of menaquinone-7 was found to be higher than that of Bacillus subtilis BSM-Control strain, which is a parent strain of Bacillus subtilis BSM-K02 mutant strain. As a result, It was confirmed that the specific yield of the ability increased 1.7 times and the productivity increased 1.9 times (FIG. 4 and Table 8).

According to the method according to one embodiment of the present invention, after 24 hours of cultivation, 5.8 g / l of cells are obtained and 21.8 mg / l of vitamin K2, i.e., menaquinone-7 can be produced, ) Was found to be 0.91 mg / L (0.91 mg MK-7 / L / hr), and the specific yield of mannquinone-7 ㎎ MK-7 / g-cell. As a result, the production of vitamin K2, i.e., menaquinone-7 using the Bacillus subtilis BSM-K02 mutant strain under optimized culture conditions, was lower than that of the parent strain Bacillus subtilis BSM- 7 productivity by 1.9 times or more to mass-produce vitamin K2, as well as to reduce the concentration of organic matter to be 3 to 8 times that of the conventional art relating to the production of menaquinone-7, thereby producing menaquinone-7 (FIG. 4 and Table 8).

The novel strain Bacillus subtilis BSM-K02 mutant strain of the present invention is excellent in the ability to produce vitamin K2, i.e., menaquinone-7, and can be obtained from the strain under the optimized culture medium and culture conditions according to the present invention, Can be mass-produced, and the production cost of menaquinone-7 can be remarkably reduced.

FIG. 1 is a graph showing the survival curves of Bacillus subtilis BSM-Control strains according to the treatment concentration of menadione according to an embodiment of the present invention.
FIG. 2 is a graph showing the relative menaquinone-7 (MK-7) produced from Bacillus subtilis Control strain according to an aromatic amino acid concentration according to an embodiment of the present invention. K2). ≪ / RTI >
FIG. 3 is a graph showing the effect of Menadione-resistant Bacillus subtilis BSM-Control mutant (N-methyl-N'-nitro-N-nitrosoguanidine) treated with UV and NTG according to an embodiment of the present invention (Menaquinone-7, MK-7; vitamin K2) distribution curve of the strain.
FIG. 4 is a graph showing the effect of menaquinone-7, which is produced from the Bacillus subtilis BSM-K02 mutant strain (A) and the parent strain Bacillus subtilis BSM-Control strain (B) MK-7; vitamin K2). Here, DO is dissolved oxygen.

Hereinafter, the constitution and effects of the present invention will be described in more detail through examples. These examples are only for illustrating the present invention, and the scope of the present invention is not limited by these examples.

Example  1: Menaquinone-7, a vitamin K2 Productive  Improved strain selection

In order to screen for new mutant strains with improved vitamin K2, namely menaquinone-7, MK-7, Bacillus subtilis sp . (UV) or NTG (nitrosoguanidine: N-methyl-N'-nitro-N-nitrosoguanidine) for inducing mutation in the strain , And the resistance to menadione (vitamin K3) and the inhibition of the production of menaquinone-7 by aromatic amino acids were evaluated to finally obtain a strain having an improved potency of menaquinone-7 as a vitamin K2 Respectively. Specifically, experiments were conducted as follows.

Example  1-1: Menadion ( menadione ) Depending on treatment concentration Bacillus Subtilly ( Bacillus subtillis ) Survival analysis of BSM-Control strain

Menadione, a vitamin K3, is a quinone skeleton structure that is a head part of menaquinone-7 (MK-7), a vitamin K2. It has a high resistance to menadione The strain can be expected to be a strain that is not inhibited by various factors during production of a large amount of quinone skeleton.

Therefore, in order to establish the experimental conditions for selecting a novel Bacillus subtilis mutant strain with improved menaquinone-7 production ability, the optimal menadione treatment for selecting a resistant strain to Bacillus subtilis mutant menadione Respectively. At this time, a strain was first prepared by treating NTG (nitrosoguanidine) with a wild-type Bacillus subtilis strain to induce mutagenesis. The strain was named Bacillus subtilis BSM-Control and used as a parent strain Respectively.

Specifically, in order to select menadione-resistant strains of Bacillus subtilis mutants, the survival rate of BSM-Control strains prepared according to the menadione treatment concentration of Bacillus subtilis BSM-Control strains prepared above was examined. To this end, the strain was inoculated into TGY medium (1% triptone, 0.5% yeast extract, 0.5% sodium chloride (NaCl), pH 7.0) and grown at 37 ° C until the OD ₆₆₀ value reached 0.2-0.5 And the cells were recovered. The recovered cells were plated on a TGY agar medium (1.5% agar supplemented) supplemented with menadione at concentrations of 0 ppm, 2.5 ppm, 5 ppm, 10 ppm, 15 ppm and 20 ppm, respectively. The recovered cells were washed with 0.85% saline, and OD ₆₆₀ was adjusted to 1.0, and the cells were spread on a TGY agar medium supplemented with menadione. After blotting, the cells were cultured at 37 DEG C for 24 hours to prepare a survival curves of the strains.

As a result, as shown in FIG. 1, 98.7% mortality was confirmed when menadione was treated at a concentration of 10 ppm, and 99.9% was observed when menadione was treated at a concentration of 15 ppm.

Thus, in order to select a novel Bacillus subtilis mutant strain with improved menaquinone-7 production ability, the optimum menadione treatment concentration for the selection of menadione resistant strains of Bacillus subtilis BSM-Control strain 15 ppm. In order to select menadione-resistant strains of Bacillus subtilis BSM-Control strain, a TGY agar medium supplemented with 15 ppm of menadione was used.

Example  1-2: Depending on the concentration of aromatic amino acid Basil Russ Subtilis ( Bacillus subtillis ) BSM -Control analysis of the relative menaquinone-7 produced from the control strain

High concentrations of L-phenylalanine, L-tryptophan and L-tyrosine, an aromatic amino acid in the medium, inhibit the production of quinone skeleton .

Therefore, in order to establish experimental conditions for selecting a novel Bacillus subtilis mutant strain with improved menaquinone-7 production ability, the degree of inhibition of the production of menaquinone-7 by aromatic amino acids was evaluated to determine the optimum aromatic amino acid, L-tyrosine, L-phenylalanine, L-tryptophan, and L-tyrosine.

Specifically, in the production of menaquinone-7, L-tryptophan, L-phenylalanine, and L-tyrosine were added to TGY medium at 0 ppm, respectively, in order to select a mutant in which inhibition of production of menaquinone- , 30 ppm, 62.5 ppm, 125 ppm and 250 ppm to investigate the ability of Bacillus subtilis BSM-Control to produce menaquion-7. To this end, the strain was grown in primary TGY medium (1% triptone, 0.5% yeast extract, 0.5% sodium chloride (NaCl), pH 7.0) for 12 hours and then the respective aromatic amino acids Gt; TGY < / RTI > medium for 72 hours and grown. At this time, the incubation temperature was 37 ° C, and the stirring speed was 140 rpm.

On the other hand, for the analysis of menaquinone-7, firstly, the cultured cells were centrifuged, isopropanol (IPA, isopropanol) was added to the precipitated cells in an amount equivalent to the weight of the cells, and hexane And extracted for 20 minutes. After the extraction, the cells were removed using a centrifuge, and the supernatant was recovered by filtration with a 0.22 μm filter. The concentration of menaquinone-7 contained in the recovered filtrate was measured by HPLC (Shimazu LC-20AD) analysis. At this time, the concentration of menaquinone-7 was analyzed using a standard curve of menaquinone-7. HPLC analysis was performed using a Shim-pack GIS-ODS column (MG 5 μm, size 4.6 mm ID × 150 mm) The concentration of menaquinone-7 was measured at an ultraviolet detector wavelength of 248 nm by flowing an organic solvent composed of methanol in a ratio of 7: 3 at a flow rate of 1 ml / min.

As a result, as shown in FIG. 2, the concentration of L-tyrosine, 62.5 ppm of L-tryptophan, and 62.5 ppm of L-phenylalanine was lower than that of TGY medium to which no aromatic amino acid was added When it was added to TGY medium, it was confirmed that menaquinone-7 was hardly produced.

On the basis of the above results, in order to select a novel Bacillus subtilis mutant strain which is not inhibited by aromatic amino acids and has improved menaquinone-7 production ability, it is preferable to use a culture medium containing L-phenylalanine, L-tryptophan and L- Optimal content concentrations were selected as 125 ppm, 62.5 ppm, and 62.5 ppm, respectively, and TGY agar medium supplemented with L-phenylalanine, L-tryptophan, and L-tyrosine at concentrations of 125 ppm, 62.5 ppm, and 62.5 ppm, respectively It is decided to use.

Example  1-3: Menaquinone-7, a vitamin K2 Productive  Selection of Excellent Mutant Candidate Strains

Experimental conditions for the selection of a novel Bacillus subtilis mutant with improved menaquinone-7, MK-7 (vitamin K2) production ability in Examples 1-1 and 1-2 were established. Specifically, in order to select a strain that is not inhibited by the menadione-resistant strain and aromatic amino acid of Bacillus subtilis BSM-Control strain, menadione was added to the TGY agar medium at a concentration of 15 ppm, and the aromatic amino acids L-phenylalanine, L-tryptophan, and L-tyrosine were added at concentrations of 125 ppm, 62.5 ppm, and 62.5 ppm, respectively.

Thus, in order to select a mutant strain excellent in production of menaquinone-7 from Bacillus subtilis BSM-Control strain, a menadione resistant mutant strain was first selected, and L-tyrosine, L-tryptophan, and L-tyrosine Were grown in TGY medium supplemented with concentrations of 125 ppm, 62.5 ppm, and 62.5 ppm, respectively, and the menaquinone-7 concentration was measured.

Specifically, Bacillus subtilis BSM-Control strain was inoculated into TGY medium and cultured until OD ₆₆₀ value became 0.2-0.5. Then, 10 ml of the culture solution was taken to induce mutation, and the plate (9 × 15 mm ) For 2 minutes and stabilized under matt condition for 3 hours. The stabilized mutant strain was centrifuged at 4,000 rpm for 10 minutes, and the cells were recovered and washed three times with 0.85% saline. 10 ml of 0.85% saline was added to the washed cells, and the mixture was spread on a TGY agar medium supplemented with menadione at a concentration of 15 ppm. After culturing, the surviving strain was recovered and cultured in TGY medium supplemented with aromatic amino acid for 72 hours. At this time, the incubation temperature was 37 ° C, and the stirring speed was 140 rpm. After culturing for 72 hours, the concentration of menaquinone-7 was measured.

On the other hand, a menadione-resistant mutation by treatment with NTG (Nitrosoguanidine (N-methyl-N'-nitro-N-nitrosoguanidine) For strain selection, 1 ml of the Bacillus subtilis BSM-Control strain grown under the same conditions as the UV treatment conditions was taken and centrifuged. After centrifugation, 1 ml of 0.85% saline containing NTG at a concentration of 150 ppm was added to the recovered cells, and NTG was treated at a temperature of 37 ° C and a stirring speed of 150 rpm for 30 minutes. The NTG-treated mutant strain was centrifuged at 4,000 rpm for 10 minutes to collect the cells and then washed three times with 0.85% saline. To the washed cells, 1 ml of 0.85% saline was added, and the mixture was spread on a TGY agar medium supplemented with menadione at a concentration of 15 ppm. After culturing, the surviving strain was recovered and cultured in TGY medium supplemented with aromatic amino acid for 72 hours. At this time, the incubation temperature was 37 ° C, and the stirring speed was 140 rpm. After culturing for 72 hours, the concentration of menaquinone-7 was measured.

As a result, as shown in Fig. 3 A, menaquinone-7 fish ability of the menadione resistant strain by the ultraviolet treatment of Bacillus subtilis BSM-Control strain was more improved by 160% than that of the parent strain, And 43% of the mutant strains were found to be mutant strains superior in the ability to produce menaquinone-7 than the parent strains.

On the other hand, as shown in FIG. 3 (B), 26% of the NTG-treated strains had a higher ability to produce menaquinone-7 than the parent strains, and a strain having an ability to produce menaquinone-7 over 140% One species was identified.

On the basis of the above results, two menadione resistant mutants by ultraviolet treatment and three menadione resistant mutants by NTG treatment were mutagenized with menaquinone-7 (MK-7; vitamin K2) Were selected as candidate strains.

Hereinafter, in Examples 1-4, the menaquinone-7 producing ability of the five candidate strains selected above was finally confirmed through flask culture.

Example  1-4: Vitamin K2, menaquinone-7 Productive  Excellent New  As a mutant strain, Bacillus Subtilis BSM Final selection of -K02 strain

The ability to produce menaquinone-7 was finally confirmed by flask culture of all five mutant candidate strains having excellent menaquinone-7 and MK-7 (vitamin K2) production ability selected in Example 1-3 above . At this time, the five mutants were named Bacillus subtilis BSM-K01-K05.

Specifically, five mutants named as above were dissolved in 2% glucose, 0.2% magnesium sulfate (MgSO ₄ ), 2% yeast extract, 1% ammonium sulfate (NH ₄ ) ₂ SO _4), 0.25% of claim 1 potassium phosphate _{(potassium phosphate, monobasic; KH 2} PO 4), 0.04% calcium chloride _{(calcium chloride, CaCl 2),} 0.035% manganese sulfate _{(mananese sulfate, MnSO 4 · H} 2 O) to Lt; / RTI > for 72 hours. Thus, the ability to produce vitamin K2, i.e., menaquinone-7, of each of the five strains was investigated. The seeds were grown in a TGY medium for 12 hours and then inoculated 10% in the flask culture. Cultivation of the seedlings and flasks was carried out at a culturing temperature of 37 ° C and a stirring speed of 140 rpm.

As a result, as shown in the following Table 1, the Bacillus subtilis menadione resistant mutant strain selected by the ultraviolet ray or NTG treatment, which was firstly selected in the above-mentioned Example 1-3, was cultured in a flask culture with Bacillus subtilis BSM -Control strain, the ability to produce menaquion-7 was improved by 33-50%.

This is because, when the mutant strains were selected, strains that were less resistant to methanion as well as less inhibition of aromatic amino acids were selected, and mutant strains capable of maintaining menaquinone-7 ability stably in comparison with the conventional mutant strain selection method can be selected .

Based on the above results, a mutant strain of Bacillus subtilis BSM-K02 was finally selected as a novel mutant strain having excellent vitamin K2 production ability. This strain was deposited with the Korea Research Institute of Bioscience & Biotechnology, and was deposited with Bacillus subtilis strain (KCTC 13028BP) as a strain.

In Example 2, conditions such as optimized medium composition and incubation temperature for menaquinone-7 production were established using the finally selected Bacillus subtilis BSM-K02 mutant strain.

Flask culture results of Bacillus subtilis menadione resistant mutants by ultraviolet or NTG treatment No. Strain name Mutation treatment method Menaquinone-7 concentration
(Mg / l) Control group
(control) Bacillus Subtilis BSM-Control - 3.13 One Bacillus Subtilis BSM-K01 Ultraviolet (UV) /
Menadione resistance 4.70 2 Bacillus Subtilis BSM-K02 Ultraviolet (UV) /
Menadione resistance 4.72 3 Bacillus Sbutilis BSM-K03 NTG /
Menadione resistance 4.32 4 Bacillus subtilis BSM-K04 NTG /
Menadione resistance 4.06 5 Bacillus subtilis BSM-K05 NTG /
Menadione resistance 4.00

Example  2: for the production of menaquinone-7 high in vitamin K2 Bacillus Subtilis BSM Optimization of culture conditions of -K02 mutant strains

Using the Bacillus subtilis BSM-K02 mutant strain finally selected in Example 1-4, conditions such as optimized medium composition and incubation temperature were established in order to highly produce vitamin K2, namely menaquinone-7. Specifically, in order to optimize the medium of Bacillus subtilis BSM-K02, a carbon source is firstly selected and an organic nitrogen source, an ammonium sulfate source (ammonium sulfate, (NH ₄ ) ₂ SO ₄ ), a source of potassium, monobasic (K ₂ HPO ₄ ), and magnesium (Mg) which are sources of potassium, potassium and phosphorus The composition ratio of magnesium sulfate (MgSO ₄ ) was optimized and the optimal culture temperature was selected. Specifically, experiments were conducted as follows.

Example  2-1: Menaquinone-7, a vitamin K2 Productive  Excellent Bacillus Subtilis  For BSM-K02 mutant strain culture Carbonic  Selection

In order to optimize the culture medium composition for the high production of vitamin K2, namely menaquinone-7, using a Bacillus subtilis BSM-K02 mutant strain, a carbon source was firstly selected.

Specifically, glucose, sucrose, fructose, and glycerine were added to a flask (0.2% magnesium sulfate (MgSO ₄ ), 2% yeast extract, (NH ₄ ) ₂ SO ₄ ), 0.25% potassium phosphate monobasic (K ₂ HPO ₄ ), 0.04% calcium chloride, CaCl ₂ , 0.035% manganese sulfate (MnSO ₄ .H ₂ O) , pH 7.0), and cultured for 140 hours to examine the ability of the strain to produce menaquinone-7. The seeds were grown in a TGY medium for 12 hours and then inoculated 10% in the flask culture. Cultivation of the seedlings and flasks was carried out at a culturing temperature of 37 ° C and a stirring speed of 140 rpm.

As a result, as shown in the following Table 2, when sucrose was used as a carbon source, menaquinone-7-producing ability was 1.2 to 1.7 times higher than that when other carbon sources such as glucose, fructose and glycerin were used And cell growth was also the best. In particular, when glycerine was used as a carbon source, the cells were hardly grown and thus menaquinone-7 was not produced at all.

Based on the above results, sucrose was selected as a carbon source for Bacillus subtilis BSM-K02 mutant strain cultivation.

Production results of menaquinone-7 of BSM-K02 mutant strain of Bacillus subtilis according to the type of carbon source Carbon source OD ₆₆₀ Menaquinone-7 concentration
(Mg / l) Glucose 3.2 3.31 Sucrose * 5.4 4.03 Fructose 2.7 2.36 Glycerin 1.1 0.00

Example  2-2: Menaquinone-7, a vitamin K2 Productive  Excellent Bacillus Subtilis  Selection of content of organic matter in medium for BSM-K02 mutant strain culture

Based on the results of Example 2-1, sucrose was selected as a carbon source for the culture of a mutant strain of Bacillus subtilis BSM-K02. In order to select the content of organic nitrogen in the culture medium, The composition ratio of the yeast extract, which is the organic matter of the cross, was examined. At this time, the culturing was performed in the same manner as in the culturing method of Example 2-1, except that the concentration of the yeast extract was changed from 0.01 (concentration 0.03%) to 1 (concentration 3%) .

As a result, as shown in the following Table 3, the cell concentration (OD ₆₆₀ value) until the composition ratio of the yeast extract as an organic substance to the sucrose as a carbon source was 0.50 (concentration 1.5%), the composition ratio of yeast extract And the number of In addition, it was confirmed that the cell concentration (OD ₆₆₀ value) was constant when the composition ratio of the yeast extract as an organic substance compared to sucrose as a carbon source was 0.50 or more.

On the other hand, the concentration of menaquinone-7 produced from the mutant Bacillus subtilis BSM-K02 showed a maximum value of 4.06 ppm when the composition ratio of the yeast extract as an organic substance, which is a carbon source, was 0.3 (concentration 1%) However, the production of menaquinone - 7 was significantly decreased as the composition ratio of yeast extract, which is an organic substance, was increased compared to sucrose, a carbon source.

Based on the above results, it was found that the optimum content of the organic matter in the medium for culturing the mutant strains of Bacillus subtilis BSM-K02 was 1: 0.3 (concentration: 1.00%) of the yeast extract, Was determined at an optimum ratio.

The degree of growth of Bacillus subtilis BSM-K02 mutant strain and the production of menaquinone-7 according to the composition ratio of yeast extract, Carbon source  Contrast yeast extract composition ratio (concentration,%) OD ₆₆₀ Menaquinone-7 concentration (mg / l) 0.01 (0.03%) 0.3 1.32 0.10 (0.30%) 3.2 3.03 0.30 (1.00%) * 5.5 4.06 0.50 (1.50%) 7.0 3.93 0.70 (2.10%) 7.3 1.32 1.00 (3.00%) 7.4 0.80

Example  2-3: Menaquinone-7, a vitamin K2 Productive  Excellent Bacillus Subtilis  Selection of the content of inorganic nutrients in the medium for BSM-K02 mutant strain culture

Based on the results of Example 2-1, sucrose was selected as the carbon source of the culture medium for the mutant strain of Bacillus subtilis BSM-K02. In order to select the content of the inorganic nitrogen source in the culture medium, The composition ratio of potassium sulfate, magnesium sulfate, potassium phosphate, and magnesium sulfate, which are the inorganic nitrogen source, ammonium sulfate, potassium and phosphorus, were investigated. Specifically, the concentration of ammonium sulfate as an inorganic mineral is 0.000 (concentration 0.00%) to 0.500 (concentration 1.50%) as compared to sucrose as a carbon source. The concentration of potassium monophosphate is 0.000 (concentration 0.00 The concentration of magnesium sulfate was adjusted by adjusting the ratio of 0.000 (concentration 0.00%) to 0.080 (concentration 0.25%) as compared with sucrose, which is a carbon source, at a ratio of 0.100 to 0.100 The effects of the changes on the production of vitamin K2, namely menaquinone-7, were investigated. At this time, the flask culture method was the same as the culture method of Example 2-1, except that 3% sucrose and 1% yeast extract (yeast extract), which is an organic substance, were added as a carbon source.

As a result, as shown in the following Table 4, in the case of ammonium sulfate as an inorganic nitrogen source, when the composition ratio of ammonium sulfate relative to sucrose as a carbon source was 0.500 (concentration: 1.50%), the Bacillus subtilis strain BSM-K02 It was confirmed that the production (%) of relative mennquinone-7 was remarkably decreased, and the cell concentration (OD ₆₆₀ value) was also decreased.

The production (%) of the relative menaquinone-7 by potassium monophosphate as the mineral source was from 0.016 (0.05% concentration) to the potassium phosphate monoxide relative to sucrose as the carbon source, %), And it was confirmed that the maximum (%) production of relative menaquinone-7 was obtained when the composition ratio of potassium monophosphate to sucrose as a carbon source was 0.050 (concentration 0.15%). It was also confirmed that the composition ratio of potassium monophosphate to sucrose as the carbon source was decreased as the composition ratio was increased to 0.050 or more. However, it was confirmed that no effect of potassium monophosphate was observed on the cell growth (OD ₆₆₀ value).

On the other hand, the production (%) of the menaquinone-7 relative to magnesium sulfate as a mineral source showed a maximum value when the composition ratio of magnesium sulfate was 0.016 (concentration: 0.05%) versus sucrose as a carbon source, and the cell concentration (OD ₆₆₀ value) In addition, it was confirmed that the composition ratio of magnesium sulfate relative to sucrose, which is a carbon source, was the maximum when the composition ratio was 0.016 (concentration 0.05%). However, it was confirmed that the production (%) of the relative menaquinone-7 by magnesium sulfate was not affected.

Based on the above results, it was found that the optimal content of inorganic nitrogen in the culture medium for culturing the mutant strains of Bacillus subtilis BSM-K02 was 1: 0.060 (concentration: 0.20%), the composition ratio of ammonium sulfate as inorganic nitrogen source to sucrose as a carbon source, The composition ratio of potassium phosphate monobasic as a carbon source to sucrose was 1: 0.050 (concentration: 0.15%), and the composition ratio of magnesium sulfate as a mineral source to sucrose as a carbon source was 1: 0.016 (concentration: 0.05%). .

The growth of Bacillus subtilis BSM-K02 mutant strain and the production of menaquinone-7 according to the composition ratio of ammonium sulfate, potassium phosphate monobasic, and magnesium sulfate compared to sucrose as a carbon source Inorganic salts Carbon source  Composition ratio
 ( density,% ) OD ₆₆₀ Relative menaquinone-7 production
(%)

Ammonium sulfate
_{((NH 4) 2 SO 4} )

0.000 (0.00%) 3.4 95 0.060 (0.20%) 5.6 100 0.160 (0.50%) 5.6 97 0.330 (1.00%) 4.2 94 0.500 (1.50%) 3.6 80


Potassium monophosphate
(K ₂ HPO ₄ )


0.000 (0.00%) 3.4 21 0.006 (0.02%) 3.7 28 0.016 (0.05%) 4.1 88 0.033 (0.10%) 4.7 90 0.050 (0.15%) * 4.9 100 0.080 (0.25%) 4.9 74 0.100 (0.30%) 4.1 50

Magnesium sulfate
(MgSO ₄₎


0.000 (0.00%) 4.4 98 0.016 (0.05%) 4.8 100 0.030 (0.10%) 4.2 97 0.050 (0.15%) 4.2 96 0.060 (0.20%) 3.9 96 0.080 (0.25%) 3.8 98

Example  2-4: Optimized Bacillus Subtilis BSM High production of menaquinone-7 using culture medium of -K02 mutant strain

Based on the results of Examples 2-1 to 2-3, 3% sucrose as a carbon source, 1% yeast extract as an organic substance, 0.2% ammonium sulfate as an inorganic substance, 0.15% Potassium monophosphate and 0.05% magnesium sulfate were determined to be contained in the optimal medium for Bacillus subtilis BSM-K02 mutant strain cultivation.

Thus, in order to confirm whether or not vitamin K2, that is, menaquion-7, can be highly produced from the above-mentioned culture medium using the optimized culture medium of the Bacillus subtilis BSM-K02 mutant strain, The production of vitamin K2, namely menaquion-7, produced from the new strain Bacillus subtilis BSM-K02 was compared using the above-mentioned optimized medium and conventional conventional medium through flask culture. At this time, the culturing conditions were the same as in the culturing method of Example 2-1, and the optimized medium contained 3% sucrose, 1% yeast extract, 0.2% ammonium sulfate, 0.15% Potassium, 0.05% magnesium sulfate, 0.04% calcium chloride, and 0.035% manganese sulfate. On the other hand, the existing medium was prepared so as to contain 3% glucose, 2% yeast extract, 1% ammonium sulfate, 0.25% potassium phosphate monobasic, 0.04% calcium chloride, and 0.035% manganese sulfate in the culture medium.

As a result, as shown in Table 5 below, when the optimum medium was used, it was confirmed that the production of menaquinone-7 from the mutant strain of Bacillus subtilis BSM-K02 was increased by 46%, and the production of manacquinone-7 The specific yield of ability was increased by 12%. It was confirmed that the menaquinone-7 concentration was 91% higher than that of the parent strain Bacillus subtilis BSM-Control in the existing medium.

Comparison of production of menaquinone-7 from Bacillus subtilis BSM-K02 mutant strains using conventional medium and optimal medium Existing badge Optimal medium Cell density
(g / l) Menaquinone-7 concentration
(Mg / l) Non-yield rate
(Specific yield)
[Menaquinone-7 (MK-7) (mg)
/ Cell (g)] Cell density
(g / l) Menaquinone-7 concentration
(Mg / l) Non-yield rate
(Specific yield)
[Menaquinone-7 (MK-7) (mg)
/ Cell (g)] 1.00 4.08 4.08 1.30 5.98 4.60

Example  2-5: Vitamin K2 for menaquinone-7 production Bacillus Subtilis  Selection of culturing pH condition of BSM-K02 mutant strain

On the basis of the optimized medium of Example 2-4, sucrose, which is a carbon source in the culture medium, was increased to 10%, and thus, yeast extract, ammonium sulfate, potassium phosphate monobasic, and magnesium sulfate Was adjusted to be 1: 0.3 (concentration: 1.00%), 1: 0.060 (concentration: 0.20%), 1: 0.050 (concentration: 0.15%), and 1: 0.016 Optimal medium was prepared. Using the prepared culture medium, a new strain of Bacillus subtilis BSM-K02 was cultured in a 5 L fermenter.

In order to investigate the degree of production of menaquinone-7 in Bacillus subtilis BSM-K02 mutant strain by pH control, the pH was not adjusted during the culture or adjusted to pH 6.8 with 5N sodium hydroxide (NaOH) The production of menaquinone-7 was examined for the case of pH 6.8 and the case of not.

On the other hand, when the pH was not controlled during the culture, the initial pH was 6.4, and as the culture progressed, the pH began to decrease and the pH value decreased to 5.5 ~ 6.0. Thereafter, the pH gradually increased as the cells lysed, and when the pH was adjusted to 6.8, the dissolution rate of the cells increased and the production of menaquinone-7 decreased.

Specifically, when the pH was changed to pH 6.8, or when the pH was not adjusted, that is, during the incubation, pH was changed without treatment with caustic soda (NaOH), the degree of menaquinone-7 production The optimized medium used for the investigation was 10% sucrose, 3% yeast extract, 0.6% ammonium sulfate, 0.5% potassium phosphate monobasic, 0.15% magnesium sulfate, 0.04% calcium chloride, and 0.035% Of manganese sulfate. On the other hand, the culture fermentation conditions were a culture temperature of 37 ° C, aeration rate of 0.5 vvm, and a stirring speed of 600 rpm. The seeds were grown in a TGY medium at a culture temperature of 37 ° C and a stirring rate of 140 rpm for 16 hours and then subjected to 4% inoculation on the optimized medium of the 5-liter fermenter.

As shown in Table 6 below, the production of menaquinone-7 was measured using a mutant strain of Bacillus subtilis BSM-K02 as a result of examination of the degree of production of menaquinone-7 with and without pH 6.8. , The fermentation time was reduced by 3 times as compared with the case where the pH was not adjusted during the cultivation at pH 6.8. In addition, the production of menaquinone-7 was increased 1.7 times by slowing the lysis rate of the cells. Thus, the productivity was 0.5 mg / L (0.5 mg / L) of menaquinone-7 (MK- 7 / l / hr). Namely, when the pH was not controlled, the final cell concentration was 5.23 g / l after 24 hours of culture, and the maximum menaquinone-7 concentration was 11.27 mg / l.

However, the specific yield, which is the ability to produce menaquinone-7 per cell, was 2.3 mg MK-7 / g-cell, which was 1.2 times less than pH 6.8 when the pH was not regulated. When the pH was not adjusted, the cell concentration was 5.23 g / l at the time of maximum menaquinone-7 production, and the cell concentration at the time of maximum menaquinone-7 production by pH adjustment was 2.36 g / Compared with the previous year.

That is, when menaquinone-7 fermentation is carried out using a mutant strain of Bacillus subtilis BSM-K02, after 10 hours of incubation, the cells start to lyse and the cell concentration decreases, and the lysis rate Showed that the pH was rapidly increased as compared with the case where the pH was not regulated, and the cell concentration was decreased by about 2 times as compared with the case where the pH was not regulated at 24 hours. As a result, when the pH was controlled, the production rate of menaquinone-7 was slowed down, and the concentration was also lowered.

Based on the above results, it was found that culturing without Bacillus subtilis BSM-K02 mutagenesis without pH control for optimal production of vitamin K2, namely menaquinone-7, was the optimal culture condition.

Results of menaquinone-7 production of Bacillus subtilis BSM-K02 mutant strain by pH control during fermentation pH adjustment (pH 6.8) No pH control Fermentation time (hr, hr) 72 24 Maximum cell density (g / l) 16.1 12.3 Final cell concentration (g / l) 2.36 5.23 The maximum menaquinone-7 concentration (mg / l) 6.93 11.97 Specific yield
[Menaquinone-7 (MK-7) (mg) / cell (g)] 2.9 2.3 Menaquinone-7 productivity per hour (hr)
[Menaquinone-7 (MK-7) (mg) / l] 0.1 0.5

Example  2-6: For the production of menaquinone-7 high in vitamin K2 Bacillus Subtilis  Selection of culture temperature condition of BSM-K02 mutant strain

It was confirmed that, when culturing the BSM-K02 mutant strain of Bacillus subtilis in Example 2-5, the pH was not regulated under optimal culture conditions.

In order to investigate the degree of production of menaquinone-7 by Bacillus subtilis BSM-K02 mutant strain according to the regulation of the culture temperature, in the 5 L fermenter, 37, 45, 45 ° C, and the degree of menaquinone-7 production of the mutant BSM-K02 strain of Bacillus subtilis BSM-K02 was examined according to the temperature change. At this time, the medium composition, culture, and seedling conditions were performed in the same manner as in Example 2-5.

As a result, as shown in the following Table 7, it was confirmed that the production of menaquinone-7 in the mutant strain of Bacillus subtilis BSM-K02 with the change of the culture temperature increased with increasing the culture temperature. When the culture temperature was 43 ° C And the maximum value was 18.9 mg / l. In addition, the specific yield and productivity, which are the ability to produce menaquinone-7 per cell, also showed maximum values at the temperature of 43 ° C, and specifically, the rate of production of menaquinone-7 per cell specific yield was 3.6 ㎎ MK-7 / g-cell and the productivity was 0.79 ㎎ MK-7 / ℓ / hr for menaquinone-7 (MK-7) Respectively. As a result, the specific yield and productivity of the production of menaquinone-7 per cell were 1.6 times higher than those of the conventional culture temperature of 37 ° C.

Based on the above results, it was found that culturing under the temperature condition of 43 ° C without pH control for optimal production of vitamin K2, that is, menaquinone-7 when cultivated with a mutant strain of Bacillus subtilis BSM-K02, Could know.

Results of menaquinone-7 production of Bacillus subtilis BSM-K02 mutant strain at different culture temperatures 37 ℃ 40 ℃ 43 ° C * 45 ° C Fermentation time (hr, hr) 24 24 24 24 Maximum cell density (g / l) 12.3 13.2 13.1 10.9 Final cell concentration (g / l) 5.23 5.23 5.23 3.30 The maximum menaquinone-7 concentration (mg / l) 11.97 13.81 18.90 9.67 Specific yield
[Menaquinone-7 (MK-7) (mg) / cell (g)] 2.3 2.6 3.6 2.9 Menaquinone-7 productivity per hour (hr)
[Menaquinone-7 (MK-7) (mg) / l] 0.50 0.57 0.79 0.40

Example  2-7: Optimized Bacillus Subtilis BSM Production of menaquinone-7 under culture conditions of -K02 mutant strain

In the case of the mutant strain of Bacillus subtilis BSM-K02 in Example 2-6, it was confirmed that culturing under the temperature condition of 43 ° C without pH control for optimal production of vitamin K2, namely menaquinone-7, Respectively. Thus, to investigate the production of menaquinone-7 in Bacillus subtilis BSM-K02 mutant strains under the optimum culture conditions established in Example 2-6.

Specifically, when the new Bacillus subtilis BSM-K02 mutant strain was cultured in a 5 L fermenter, the culture was incubated for 6 hours at an initial temperature of 37 ° C without pH control, and then the culture temperature condition at 6 hours was changed to 43 ° C and the degree of menaquinone-7 production of the strain was investigated. As a control, Bacillus subtilis BSM-Control strains were used as the parent strains. The culture conditions, culture conditions, and seed conditions were the same as in Example 2-6.

As a result, as shown in Fig. 4, under the optimal culture conditions, the Bacillus subtilis BSM-K02 mutant strain showed a menaquinone-7 fermentation form similar to the parent strain Bacillus subtilis BSM-Control strain Respectively. However, the production capacity of menaquinone-7 was more than two times higher than that of Bacillus subtilis BSM-Control strain, which is a parent strain of Bacillus subtilis BSM-K02 mutant strain. After 24 hours of fermentation, 21.8 mg / Vitamin K2, i.e., menaquinone-7. This was 1.9 times higher than the fermentation concentration of menaquinone-7 of the parent strain Bacillus subtilis BSM-Control, 11.4 mg / l.

Comparison of the production of menaquinone-7 from the Bacillus subtilis BSM-K02 mutant strain and the parent strain Bacillus subtilis BSM-Control strain under optimal culture conditions Bacillus Subtilis BSM-K02
(Mutant strain) Bacillus Subtilis
BSM -Control
( Parent strain ) Fermentation time (hours) 24 24 Maximum cell density (g / l) 14.0 15.1 Final cell concentration (g / l) 5.8 5.1 The maximum menaquinone-7 concentration (mg / l) 21.8 11.4 Specific yield
[Menaquinone-7 (MK-7) (mg) / cell (g)] 3.8 2.2 Menaquinone-7 productivity per hour (hr)
[Menaquinone-7 (MK-7) (mg) / l] 0.91 0.48

These results are shown in Table 8. As shown in Table 8, when the BSM-K02 mutant strain of Bacillus subtilis BSM-Control strain having the parent strain Bacillus subtilis BSM- yield increased 1.7 times and productivity increased 1.9 times.

As a result, the production of vitamin K2, i.e., menaquinone-7 using the Bacillus subtilis BSM-K02 mutant strain under optimized culture conditions, was lower than that of the parent strain Bacillus subtilis BSM- 7 productivity can be increased by more than 1.9 times, and the concentration of organic matter can be reduced by 3 to 8 times as compared with the conventional art relating to the production of menaquinone-7, which is economical in producing menaquinone-7 .

Institution name: Korea Biotechnology Research Institute

Accession number: KCTC13028BP

Checked on: 20160525

Claims (8)

Menaquinone -7 (MK-7) having a producing ability of Bacillus subtilis (Bacillus subtillis) BSM-K02 mutant strain (KCTC13028BP).
A method for mass production of menaquinone-7 (MK-7) comprising culturing a Bacillus subtilis BSM-K02 mutant strain (KCTC13028BP).
The method of mass-producing menaquinone-7 (MK-7) according to claim 2, wherein the strain is cultured in a medium containing a carbon source, an organic nitrogen source and an inorganic nitrogen source.
The method for mass-producing menaquinone-7 (MK-7) according to claim 3, wherein the carbon source is sucrose.
The method of mass production of menaquinone-7 (MK-7) according to claim 3, wherein the organic substance is a yeast extract.
The method according to claim 3, wherein the inorganic substance is selected from the group consisting of ammonium sulfate (NH ₄ ) ₂ SO ₄ , potassium phosphate monobasic (K ₂ HPO ₄ ), and magnesium sulfate (MgSO ₄ ) Method for mass production of menaquinone-7 (MK-7).
The culture medium according to claim 3, wherein the medium comprises sucrose, which is a carbon source, and yeast extract, which is an organic substance, in a ratio of 1: 0.1 to 0.5, and sucrose as a carbon source and ammonium sulfate ((NH ₄ ) ₂ SO ₄ ) 1: 0.06 to 0.33 weight ratio, sucrose which is a carbon source and potassium monophosphate (K ₂ HPO ₄ ) which is an inorganic mineral are contained in a ratio of 1: 0.016 to 0.050 by weight, and sucrose which is a carbon source and magnesium sulfate MgSO ₄ ) is contained at a weight ratio of 1: 0.016 to 0.080. The mass production method of menaquinone-7 (MK-7)
4. The method according to claim 3, wherein the culturing is carried out without pH adjustment during culturing (MK-7) is carried out at a temperature ranging from 39 to 44 ° C.

Images