• Microbiology and Biotechnology Letters
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• v.29 no.1
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• pp.50-55
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• 2001

A new bacteriocin produced by Bacillus subtilis cx1, was partially purified and characterized. The bactericoin from B. subtilis cx1 was stable in the range of pH 2.5-9.5. B. subtilis csx1 retained its antimicrobial activity to long-term exposure at $-20^{\circ}C$ and $-70^{\circ}C$. However, B. subtilis cx1 was inactivated completely within 15 min over $60^{\circ}C$ and lost 50% of its antimicrobial activity within 15 min at $50^{\circ}C$, B. subtilis cx1 was inactivated by protease, trypsin, proteinase K and carboxypeptidase, which indi-cates its protein nature. Direct detection of the antimicrobial activity on Tricine -SDS-PAGE suggested an apparent molecular mass of about 9,500 dalton.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.25-31
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• 2005

A soil bacterium, Bacillus subtilis HJ927, exhibiting strong antagonistic property against pathogenic fungi was isolated from pepper fields infested with Phytophthora capsici. Pepper plants inoculated with P. capsici revealed severe root mortality while plants co-inoculated with B. subtilis HJ927 and P. capsici showed drastically reduced root mortality. Low molecular weight substances released by B. subtilis HJ927 mediated the plant protective effect. The anti-fungal compounds released by B. subtilis HJ927 were identified as 3-methylbutyric acid, 2-methylbutyric acid, and methyl 2-hydroxy, 3-phenylpropanoate by high-performance liquid chromatography and gas chromatography-mass spectrometry. In addition to these compounds, B. subtilis HJ927 also produced ${\beta}$-1,3-glucanase, a hydrolytic enzyme implicated in antifungal activity.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.2
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• pp.163-170
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• 2016

This study investigated the quality characteristics of doenjang prepared with different Bacillus strains (Bacillus subtilis KACC 15935 and Bacillus subtilis HJ18-9). Changes in enzyme activities (protease, cellulase, and ${\alpha}-amylase$), amino-type nitrogen and ammonia-type nitrogen contents, and reducing sugar were investigated during the fermentation period. Enzymes such as protease, cellulase, and ${\alpha}-amylase$ play important roles in the composition of nutrients, as well as in the flavor and taste of doenjang. After 60 days of fermentation, protease activities in control doenjang, and doenjang fermented with B. subtilis KACC 15935, and B. subtilis HJ18-9 increased significantly up to $382.58{\pm}4.02$, $342.58{\pm}7.94$, and $392.58{\pm}1.91unit/g$, respectively (p<0.05). At the beginning of fermentation, protease activities were in the range of 156.88~182.71 unit/g. Cellulase and ${\alpha}-amylase$ activities of doenjang in HJ18-9 were higher than those in other samples. After fermentation, amino-type nitrogen in doenjang fermented with control, B. subtilis KACC 15935, and B. subtilis HJ18-9 increased significantly up to $143.25{\pm}1.62$, $141.86{\pm}2.14$, and $150.23{\pm}1.62mg%$, respectively (p<0.05). These results suggest that B. subtilis HJ18-9 is a suitable starter for the preparation of doenjang.

• Food Science and Preservation
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• v.21 no.2
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• pp.286-293
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• 2014

In this study, one GRAS strain was screened from doenjang, a traditional Korean fermented food, as a microorganism producing amylase due to the formation of a clear zone on the medium including soluble starch. From the analysis of the gene sequence of 16S ribosomal RNA, the strain was identified as Bacillus subtilis and was therefore named Bacillus subtilis CBD2. When the nutrient broth medium was prepared with 3% NaCl, 5% glucose, and the initial medium pH 7.0, the B. subtilis CBD2 showed maximum growth. Among soluble starch, corn starch, maize amylopectin, and wheat starch, soluble starch was the most effective carbon source in the production of amylase by B. subtilis CBD2. The amylase from B. subtilis CBD2 showed the highest activities at pH 8.0 and $50^{\circ}C$, and corn starch was the most proper substrate for the enzyme activity. When corn starch was used as a substrate, the production of sugars through enzyme activity increased for 24 h, and then the enzyme activity became constant.

• Journal of Microbiology
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• v.42 no.2
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• pp.111-116
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• 2004

It is known that Bacillus subtilis glutamyl-tRNA synthetase (GluRS) mischarges E. coli $tRNA_{1}$$^{Gln}$ with glutamate in vitro. It has also been established that the expression of B. subtilis GluRS in Escherichia coli results in the death of the host cell. To ascertain whether E. coli growth inhibition caused by B. subtilis GluRS synthesis is a consequence of Glu-$tRNA_{1}$$^{Gln}$ formation, we constructed an in vivo test system, in which B. subtilis GluRS gene expression is controlled by IPTG. Such a system permits the investigation of factors affecting E. coli growth. Expression of E. coli glutaminyl-tRNA synthetase (GlnRS) also amelio-rated growth inhibition, presumably by competitively preventing $tRNA_{1}$$^{Gln}$ misacylation. However, when amounts of up to 10 mM L-glutamine, the cognate amino acid for acylation of $tRNA_{1}$$^{Gln}$, were added to the growth medium, cell growth was unaffected. Overexpression of the B. subtilis gatCAB gene encoding Glu-$tRNA^{Gln}$ amidotransferase (Glu-AdT) rescued cells from toxic effects caused by the formation of the mis-charging GluRS. This result indicates that B. subtilis Glu-AdT recognizes the mischarged E. coli Glu-$tRNA_{1}$$^{Gln}$, and converts it to the cognate Gln-$tRNA_{1}$$^{Gln}$ species. B. subtilis GluRS-dependent Glu-$tRNA_{1}$$^{Gln}$ formation may cause growth inhibition in the transformed E. coli strain, possibly due to abnormal protein synthesis.

• Journal of Microbiology
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• v.43 no.5
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• pp.443-450
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• 2005

The multi-host pathogen, Pseudomonas aeruginosa, possesses an extraordinary versatility which makes it capable of surviving the adverse conditions provided by environmental, host, and, presumably, competing microbial factors in its natural habitats. Here, we investigated the P. aeruginosa-Bacillus subtilis interaction in laboratory conditions and found that some P. aeruginosa strains can outcompete B. subtilis in mixed planktonic cultures. This is accompanied by the loss of B. subtilis viability. The bactericidal activity of P. aeruginosa is measured on B. subtilis plate cultures. The bactericidal activity is attenuated in pqsA, mvfR, lasR, pilB, gacA, dsbA, rpoS, and phnAB mutants. These results suggest that P. aeruginosa utilizes a subset of conserved virulence pathways in order to survive the conditions provided by its bacterial neighbors.

• Journal of Life Science
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• v.22 no.7
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• pp.912-919
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• 2012

A Bacillus sp. strain producing celluase and xylanase was isolated from environmental soil with LB agar plate containing carboxymethylcellulose (CM-cellulose) and beechwood xylan stained with trypan blue as substrates, respectively. Based on the 16S rRNA gene sequence and API 50 CHL test, the strain was identified as B. subtilis and named B. subtilis NC1. The cellulase and xylanase from B. subtilis NC1 exhibited the highest activities for CM-cellulose and beechwood xylan as substrate, respectively, and both enzymes showed the maximum activity at pH 5.0 and $50^{\circ}C$. We cloned and sequenced the genes for cellulase and xylanase from genomic DNA of the B. subtilis NC1 by the shot-gun cloning method. The cloned cellulase and xylanase genes consisted of a 1,500 bp open reading frame (ORF) encoding a 499 amino acid protein with a calculated molecular mass of 55,251 Da and a 1,269 bp ORF encoding a 422 amino acid protein with a calculated molecular mass of 47,423 Da, respectively. The deduced amino acid sequences from the genes of cellulase and xylanase showed high identity with glycosyl hydrolases family (GH) 5 and 30, respectively.

• KSBB Journal
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• v.26 no.6
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• pp.517-522
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• 2011

In our previous study, we isolated and characterized a 1-deoxynojirimycin (DNJ)-producing bacterium, Bacillus subtilis MORI, from chungkookjang, a Korean traditional food. B. subtilis MORI was subjected to ${\gamma}$-irradiation and the resulting bacteria were screened for increased DNJ production. A mutant was identified that produced 7.6 times more DNJ and named B. subtilis MORI 3K-85. In this study, the protein profiles of both strains were compared by one-dimensional and two-dimensional gel electrophoresis (1-DE and 2-DE, respectively) under both native and denaturing conditions. The 1-DE native-PAGE and 1-DE SDS-PAGE analyses identified 5 and 7 bands, respectively, that were found at higher concentrations in B. subtilis MORI 3K-85 than in B. subtilis MORI. Similarly, 2-DE analyses identified 20 protein spots which were found at higher concentrations in B. subtilis MORI 3K-85. The peptide mass profiles of these 20 proteins were analyzed by MALDI-TOF and compared with peptide sequences of B. subtilis and B. amyloliquefaciens in the MASCOT database. This screening suggested that three dehydrogenases, an aldolase, a synthetase, an isomerase, a reductase, and a peroxidase are elevated in B. subtilis MORI 3K-85. Based on this data, one or more of the elevated 8 enzymes might be related to the DNJ biosynthetic pathway.

• Food Science and Preservation
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• v.21 no.1
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• pp.121-128
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• 2014

This study was conducted in order to investigate the change of isoflavone composition (glycoside and bio-active aglycone), and to evaluate the quality characteristics of Cheonggukjang, which was prepared by different bacillus strains. After the 48-hour fermentation, the contents of daidzein, genistein, and glycitein in the Bacillus subtilis HJ18-3 have significantly increased up to approximately $89.06{\pm}3.59$, $10.36{\pm}0.28$, and $101.37{\pm}3.67ug/g$, respectively. The contents of daidzein, genistein, and glycitein in the Bacillus subtilis KACC 15935 were $38.88{\pm}5.39$, $12.58{\pm}2.14$, and $80.13{\pm}0.71ug/g$, respectively. The original content of daidzein was 3.96 ug/g, while genistein and glycitein were not measured. However, the contents of daidzen and genistein in HJ18-3 and in KACC 15935 were decreased. The ${\alpha}$-Amylase and cellulase activities of Chungkookjang in HJ18-3 were higher than in the KACC 15935. The contents of Chungkookjang in HJ18-3 were $29.70{\pm}11.66$ and $4861.3{\pm}388.07unit/g$, respectively. The amino type nitrogen contents and ammonia type nitrogen contents of Chungkookjang in KACC 15935 were higher than in the HJ18-3. These results suggested that it could be used to increase the bioactivity via fermentation with the Bacillus subtilis possessing a ${\beta}$-glucosidase activity with a view towards the development of functional foods.

• Microbiology and Biotechnology Letters
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• v.30 no.3
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• pp.210-215
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• 2002

A bacterium degrading soy protein was isolated from Korean traditional fermented foods. The isolated strain was identified as Bacillus subtilis, and named as B. subtilis EB464. The optimum pH and temperature of the protease produced by 5. subtilis EB464 were pH 9.0 and $50^{\circ}C$, respectively. The protease was stable in the range of pH 6~10 and below $40^{\circ}C$. The content of water-soluble protein and free amino acid of the medium were increased from 4.2% to 20.6% and ken 1.9% to 22.0%, respectively, by solid-state fermentation of soybean meal with B. subtilis EB464 for 72 h.