• Microbiology and Biotechnology Letters
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• v.38 no.1
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• pp.84-92
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• 2010

Antibacterial compound from Bacillus subtilis MJP1 was purified using C18 Sep-Pak cartridge, ion exchange chromatography, and gel filtration chromatography. The purified antibacterial compound showed antibacterial activity against Listeria monocytogenes, Bacillus subtilis, Staphylococcus aureus subsp. aureus, and Enterococcus faecalis. The purified antibacterial compound was found to be stable at $100^{\circ}C$ for 5 min and in the pH range of 3.0~9.0, but it was unstable at pH 10.0. It was inactivated by proteinase K and pronase E, and heat treatment at $121^{\circ}C$ for 15 min, but it was stable with lipase and $\alpha$-amylase treatment, which indicated its proteineous nature. Ultra performance liquid chromatography and electrospray ionization tandem mass spectrometry analysis were used to identify the purified antibacterial compound and confirmed the existence of two peptides (3356.54 Da, 3400.5244 Da).

• Journal of Mushroom
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• v.21 no.3
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• pp.140-144
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• 2023

The objective of this study was to achieve biological control of green mold disease in Pyogo mushrooms using antagonistic microorganisms. Bacillus subtilis BSM320 cells inhibited mycelial growth by 48-60% against three Trichodermaisolates including T. hazianumisolated from the substrates of Lentinula edodes, showing their antifungal activity.The bacteria were cultured to a high density of 4.2 × 10⁹±113.7 cfu/mlin aqueous extract of composted spent mushroom substrates of L. edodes containing 1% glucose and showed a higher growth rate than that observed when using the commercial medium, Luria-Bertani broth. The bacterial culture showed a 75% protective effect without damaging the mushroom fruiting bodies. These results suggest that B. subtilis BSM320culture is suitable for biological control of green mold disease during mushroom cultivation.

• Microbiology and Biotechnology Letters
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• v.37 no.1
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• pp.1-9
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• 2009

The genetic monitoring method was developed for the rapid detection of the PGPR and biocontrol agent, B. subtilis AH18 in red-pepper field soil by multiplex PCR using sid, aec and cel gene primers. The monitoring of B. subtilis AH18 in the soil was carried by amplified a 2,3-dihydro-2,3-dihydroxy benzoate dehydrogenase [EC: 1. 3. 1. 28]gene (sid - 794 bp : EF408238) which is a key enzyme of siderophore synthesis, an auxin efflux carrier gene (aec - 1,052 bp : EF408239) and a cellulase gene (cel - 1,582 bp : EF070194). The natural un sterilized soil was inoculated with B. subtilis AH18 to determine the sensitivity ($1.8\times10^5$ cfu/g) of multiplex PCR for the rapid dectection and then the strain was monitored successfully in rhizosphere or non-rhizosphere soil of red-pepper cultural soil. At 3 weeks after the treatment, density of the strain was monitored more abundantly in rhizosphere soil.

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

• Korean Journal of Food Science and Technology
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• v.40 no.5
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• pp.558-561
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• 2008

Culture broth of Bacillus subtilis Y3-7 in tryptic soy broth (TSB) isolated from Korean traditional fermented food was evaluated for the inhibition of $\alpha$-glucosidase. The results of in vitro studies using the yeast $\alpha$-glucosidase demonstrated that the culture broth exerted inhibitory effects on $\alpha$-glucosidase with $IC_{50}$ value of 1.62 mg/mL, and functioned as a competitive inhibitor. Furthermore, the culture broth of B. subtilis Y3-7 significantly improved glucose tolerance in normal and streptozotocin-induced diabetic mice. The blood glucose levels in the mice receiving sucrose supplementation in the culture broth (1 g/kg, 2 g/kg) were measured at 48.7%, which corresponded to 22.2% of the levels measured in the control mice. These results indicated that the culture broth of B. subtilis Y3-7 in TSB might be considered as a useful compound for the preparation of functional foods for diabetic patients.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.827-832
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• 2005

Bacillus subtilis JM3 protease from naturally fermented anchovy sauce was partially purified in 40-60% ammonium sulfate fraction. To accelerate fermentation of anchovy sauce, 2 and 4% crude B. subtilis JM3 proteases were added to 6 month-ripened anchovy sauce, and their hydrolysis degrees and amino-nitrogen contents were investigated at different storage times. Low molecular weight (LMW) peptide was purified by ultrafiltration ana gel permeation chromatography from anchovy sauce manufactured with B, subtilis JM3 protease. Anchovy sauces with 2 and 4% proteases increased hydrolysis rate by 27 and 32%, respectively. Amino-nitrogen contents of anchovy sauces fermented with 2 and 4% proteases were twofold higher than that of control. Control showed five peptide peaks on Bio-Rad P2 gel permeation chromatography spectrum, whereas anchovy sauces with 2 and 4% B. subtilis JM3 proteases showed six and seven peaks, respectively. ACE inhibitory activity was highest in peak 6 (43.75%) of anchovy sauce with 2% protease, followed by peak 5 (34.82%) of control. DPPH radical-scavenging effect was higher than 50% in all samples. Cytotoxicity was highest in peak 3 (44.12%) of control, fellowed by peak 5 (42.04%) of anchovy sauce with 4% protease.

• Journal of Microbiology
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• v.34 no.1
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• pp.74-81
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• 1996

Two secretion vectors, pUBA240 and pUB340 were constructed by using the promoter and secretory signal region of the .alpha.-amylase gene from an .alpha.-amylase hyperproducing strain, Bacillus subtilis NA64. In this secretion vector system, various restriction enzyme sites are located immediately after the proregion of the .alpha.-amylase gene for easy replacement of various foregn structural genes. To evaluate this secretion vectors, the .betha.-lactamase gene of pBR322 was used as a reporter gene. The expressed and biologically active .betha.-lactamase was secreted into the culture broth from B. subtilis LKS86 transformants harboring each .betha.-lactamase secreting plasmid, pUBAbla and pUBSble. In both cases, more than 92% of expressed .betha.- lactamases were located idn the culture medium. The amount of the secreted .betha.-lactamase was about 80% of the total secreted proteins in the culture medium.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.262-273
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• 1987

The replication region of the chloramphenical resistance plasmid pSBK203 of Staphylococcus aureus was cloned using pBR322 and pBD9 as vectors. Cloned replication tegion and chloramphenicol resistance gene were recombined to pBR322. The reconstructed vector behaved as a shuttle vector for E. coli and B. subtilis.

• Food Science and Preservation
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• v.15 no.2
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• pp.169-173
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• 2008

Bacillus subtilis subsp. subtilis constitutes 90% of the total viable bacteria present on Capsosiphon fulvescens. We found that hydrogen peroxide (50 ppm) and NaOCl (50 ppm) were more effective than electrolyzed water (EW, 50ppm) against B. subtilis subsp. subtilis that was isolated from this seaweed. Relative to a control, 50 ppm hydrogen peroxide reduced the total viable population by $1.8{\pm}0.4$ log CFU/g, whereas 50 ppm EW increased the total viable population by $1.7{\pm}0.5$ log CFU/g. CFUs were evaluated following 30 days of storage at $4^{\circ}C$ using air- and vacuum-packaging. Samples treated with 50 ppm hydrogen peroxide and NaOCl showed a $1.6{\pm}0.1$-fold decrease in initial hardness ($7.9{\times}10^6dyne/cm^2$), while the samples treated with 50 ppm EW had a $2.1{\pm}0.1$-fold decrease in initial hardness ($7.9{\times}10^6dyne/cm^2$). Again, measurements were performed after storage at $4^{\circ}C$ for 20 days. This study indicates that B. subtilis subsp. subtilis is the most common contaminant in aerobically or anaerobically packaged seaweed and should therefore be the main target for quality control during long-term storage. Hydrogen peroxide and NaOCl are more effective than EW in inhibiting B. subtilis subsp. subtilis and in reducing total bacterial loads in air- and vacuum-packaged seaweed.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1015-1025
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• 2015

The development of diverse polymyxin derivatives is needed to solve the toxicity and resistance problems of polymyxins. However, no platform has generated polymyxin derivatives by genetically engineering a polymyxin synthetase, which is a nonribosomal peptide synthetase. In this study, we present a two-step approach for the construction of engineered polymyxin synthetases by substituting the adenylation (A) domains of polymyxin A synthetase, which is encoded by the pmxABCDE gene cluster of Paenibacillus polymyxa E681. First, the seventh L-threonine-specific A-domain region in pmxA was substituted with the L-leucine-specific A-domain region obtained from P. polymyxa ATCC21830 to make polymyxin E synthetase, and then the sixth D-leucine-specific A-domain region (A_6-D-Leu-domain) was substituted with the D-phenylalanine-specific A-domain region (A_6-D-Phe-domain) obtained from P. polymyxa F4 to make polymyxin B synthetase. This step was performed in Escherichia coli on a pmxA-containing fosmid, using the lambda Red recombination system and the sacB gene as a counter-selectable marker. Next, the modified pmxA gene was fused to pmxBCDE on the chromosome of Bacillus subtilis BSK4dA, and the resulting recombinant strains BSK4-PB and BSK4-PE were confirmed to produce polymyxins B and E, respectively. We also succeeded in constructing the B. subtilis BSK4-PP strain, which produces polymyxin P, by singly substituting the A_6-D-Leu-domain with the A_6-D-Phe-domain. This is the first report in which polymyxin derivatives were generated by genetically engineering polymyxin synthetases. The two recombinant B. subtilis strains will be useful for improving the commercial production of polymyxins B and E, and they will facilitate the generation of novel polymyxin derivatives.