• The Korean Journal of Mycology
• /
• v.24 no.4 s.79
• /
• pp.293-304
• /
• 1996

A bacterial strain, KSl, possessing strong antifungal activity was isolated from soil samples of ginseng fields and identified as Bacillus subtilis. In greenhouse test, the culture filtrate of B. subtilis KS1 showed strong protective effect against several fungal diseases of agricultural plants such as cucumber gray mold and wheat leaf rust. In addition, the crude butanol fraction of the culture filtrate exhibited antagonistic effect against several fungi including plant or human pathogens, such as Botrytis maydis, Chytridium lagenarium and Candida albicans. The antifungal compound, SW1, produced by B. subtilis KS1 was purified through consecutive chromatographic separations on a pep-RPC column and a ${\mu}$ Bondapak $C_{18}$ reverse phase column. Temperature and pH showed little effect on the stability of the compound in the ranges $-20-121^{\circ}C$ and pH 4.0-10.0, respectively. The composition and structural characteristics of SW1 were analysed by HPLC and by $^1H-,\;^1H-^1H-COSY$, NOESY, COSY-NOESY and HOHAHA NMR spectroscopy, respectively, which revealed that the compound belongs to iturin A, a typical cyclic antifungal compound produced by B. subtilis. In contrast to the previously reported iturin A compounds which have one or no $-CH_3$ side chain in the hydrophobic hydrocarbon chain of ${\beta}-amino$ acids, SW1 was shown to have a ${\beta}-amino$ acid containing 12-carbon skeleton with two $-CH_3$ side chains.

• Applied Biological Chemistry
• /
• v.41 no.5
• /
• pp.349-354
• /
• 1998

The protease produced by Bacillus subtilis YG-95 was purified by precipitating with ammonium sulfate, DEAE-sepharose 6B and Sephadex G-100 column chromatogtaphies and its purified enzymological characteritics were investigated. The molecular weight of purified protease was estimated about 43kilodalton by SDS PAGE The optimum pH and temperature for the purified protease activity were pH 10.0 and $55^{\circ}C$, respectively. The enzyme was stable in broad range of pH 5.0 to 12.0. and at the below $45^{\circ}C$. The purified enzyme activty was inhibited by $Fe^{3+}$ and $Al^{3+}$. The activity was significantly inhibited more than 80% by O-Phenanthroline, PMSF and SDS. The $K_m$ value of the purified enzyme against Soy Protein Isolate as a substrate was 1.28 mg/ml.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.6
• /
• pp.1039-1043
• /
• 1997

Correlation among color intensity, electron donating ability to $\alpha$, $\alpha$-diphenyl-$\beta$-dicrylhydrazy(DPPH) and cultivation conditions by Bacillus subtilis DC-2 were tested with response surface methodology. Both of pigment generation ability and DPPH were more affected by temperature than any other factor. The highest correlation was appeared between color intensity and DPPH as 0.8364 which is significant at 1% level. After fixing cultivation time which is not significant at 10% level to 84hrs as optical cultivation time, response surface methodology was conducted in regarding temperature and color intensity. As a result of overlapped contour map of color intensity and DPPH, when cultivation temperature was in the range of 38.9~41.1$^{\circ}C$ and pH was in the range of 8.34~9.12, optical density of color intensity was predicted higher than 0.374 at 390nm and DPPH was infered higher than 1.310 at 528nm. In the range of optical culture condition, cultivation temperature, pH and cultivation time was fixed to 4$0^{\circ}C$, 8.5 and 85hrs, respectively. In resulting, observation value of color intensity and DPPH was in the range of anticipation value as 0.386 at 390nm and 1.332 at 528nm respectively.

• Korean Journal of Agricultural Science
• /
• v.49 no.4
• /
• pp.995-1001
• /
• 2022

The purpose of this study was to compare the effect of solid-state fermentation on soybean using three microbial strains under four different fermentation times. Soybean was fermented for 12, 24, 36 or 48 hours with highly proteolytic microbes, either Bacillus amyloliquefaciens (BA), B. subtilis (BS), or B. subtilis var. natto (BN), and levels of total protein concentration, protein distribution, and antioxidant activity were analyzed. Total protein was highest in the BS 12 h group (9.21 ㎍·µL^-1) and lowest in BN 48 h (6.80 ㎍·µL^-1), respectively (p < 0.001). Furthermore, three microbes decomposed large molecular weight proteins as well as major allergens of soybean such as β-conglycinin, Gly m Bd 30K, and glycinin. Each treatment group showed the highest degradation rate at 48 h fermentation and among the three microbes, BS showed a relatively higher degradation rate. The radical scavenging ability, known as an indicator of antioxidant activity, showed a significant increase in all treatment groups except BA 24 h. The results from this study suggest that protein concentration, and degradation and antioxidant activity were affected by different types of microbial trains and fermentation period and that B. subtilis fermentation might be the most effective way to increase nutritional and functional properties of soybean.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.11
• /
• pp.1462-1470
• /
• 2022

Natural antimicrobial substances are needed as alternatives to synthetic antimicrobials to protect against foodborne pathogens. In this study, a bacteriocin-producing bacterium, Bacillus subtilis HD15, was isolated from doenjang, a traditional Korean fermented soybean paste. We sequenced the complete genome of B. subtilis HD15. This genome size was 4,173,431 bp with a G + C content of of 43.58%, 4,305 genes, and 4,222 protein-coding genes with predicted functions, including a subtilosin A gene cluster. The bacteriocin was purified by ammonium sulfate precipitation, Diethylaminoethanol-Sepharose chromatography, and Sephacryl gel filtration, with 12.4-fold purification and 26.2% yield, respectively. The purified protein had a molecular weight of 3.6 kDa. The N-terminal amino acid sequence showed the highest similarity to Bacillus subtilis 168 subtilosin A (78%) but only 68% similarity to B. tequilensis subtilosin proteins, indicating that the antimicrobial substance isolated from B. subtilis HD15 is a novel bacteriocin related to subtilosin A. The purified protein from B. subtilis HD15 exhibited high antimicrobial activity against Listeria monocytogenes and Bacillus cereus. It showed stable activity in the range 0-70℃ and pH 2-10 and was completely inhibited by protease, proteinase K, and pronase E treatment, suggesting that it is a proteinaceous substance. These findings support the potential industrial applications of the novel bacteriocin purified from B. subtilis HD15.

• Culinary science and hospitality research
• /
• v.12 no.4 s.31
• /
• pp.225-235
• /
• 2006

This study was carried out to investigate the optimum conditions for the preparation of natto(unripe Chungkukjang) using Sowonkong(small soybeans) and Bacillus subtilis KCCM 11315. The changes in the contents of amino-type nitrogen, ammonia-type nitrogen, total acidity and total sugar, and those in the pH, browning materials and microbial growth were determined during fermentation and aging of natto(unripe Chungkukjang). The amounts of amino-type nitrogen and ammonia-type nitrogen were increased gradually during the fermentation at $40^{\circ}C$ for 72 hours, but those of total acidity and total sugar were decreased. The pH was gradually alkalized, and more water soluble browning materials were produced during fermentation. The number of viable cells was the highest at the 36 hours of fermentation. The content of ammonia-type nitrogen was significantly decreased during aging at $4^{\circ}C$ for 48 hours. In view of the results as above, it seems possible to conclude that the natto(unripe Chungkukjang) fermented by Bacillus subtilis KCCM 11315 at $40^{\circ}C$ for 36 hours and then aged at $4^{\circ}C$ for 48 hours was suitable for manufacturing natto(unripe Chungkukjang).

• The Korean Journal of Food And Nutrition
• /
• v.18 no.1
• /
• pp.39-47
• /
• 2005

Using the bacteria isolated from Chungkookjang, Bacillus sublilis MG410 which is excellent in fibrinolytic enzyme activity was isolated. In increase the high production of fibrinolytic enzyme from Bacillus sublilis MG410, the effect of various carbon sources, nitrogen sources, inorganic sources, the initial pH of medium were investigated. The most effective carbon and nitrogen sources were founded cellobiose 0.5%(w/v) and soybean meal 2%(w/v) respectively. None of inorganic sources examined had any detectable stimulating effect on fibrinolytic enzyme production except Na₂HPO₄·12H₂O. The initial optimum pH for fibrinolytic enzyme production ranged from 5∼6 and agitation speed was effect at 150rpm. In jar fermentor experiments under optimal culture conditions, the activity of fibrinolytic enzyme reached about 5.050 unit after 48hours.

• Applied Biological Chemistry
• /
• v.48 no.3
• /
• pp.207-211
• /
• 2005

The metabolites released from cultures of rhizosphere bacteria can inhibit plant growth. Bacillus subtilis IJ-31 inhibited plant growth by the production of hydrocinnamic acid (HCA). The production of HCA by plant-growth inhibiting rhizobacterium B. subtilis IJ-31 was optimized. $90.5\;{\mu}g/ml$ of HCA was obtained under the condition of 1% rice bran as carbon source, 0.5% tryptone as nitrogen source, 0.1% $ZnCl_2$ as metal source at $37^{\circ}C$ for 60 h (pH 7.0). The optimal condition for the HCA production by B. subtilis IJ-31 in the jar fermenter was established using response surface methodology (RSM) of statistical analysis system(SAS) program. The production of HCA by B. subtilis IJ-31 in the jar fermenter culture reached $102.99\;{\mu}g/ml$ when 2.24% soil extracts was added and agitation speed was 290 rpm under the same condition. And the experimental value of HCA production is $102.5\;{\mu}g/ml$ in the same culture condition. The production of HCA by B. subtilis IJ-31 is higher as 12% than that from the flask culture.

• Fashion & Textile Research Journal
• /
• v.8 no.2
• /
• pp.239-244
• /
• 2006

For studies of fibrinolytic enzyme strain K-54 was isolated from the Korean traditional food chungkook-jang. Isolated strains K-54 was identified as Bacillus subtilis. The molecular weight of fibrinolytic enzyme from B. subtilis K-54 was 27 kDa. Optimum temperature for fibrinolytic enzyme of B. subtilis K-54 was $50-70^{\circ}C$ and optimum pH for producing the enzyme of this strain was ranging from 8 to 12. Also, it was found out enzyme activity was completely inhibited by 1mM PMSF. The result indicated this enzyme was thermo-stable alkaline serine protease with strong fibrinolytic activity. The wool and silk were treated with protease of B. subtilis K-54. As a result, the property of dyeing of wool fabrics was increased. By the increasing of treatment time became smoothened. But the change of mechanical properties were not changed.