• Korean Journal of Microbiology
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• v.17 no.2
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• pp.72-80
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• 1979

24 samples which were incoulated with Aspergillus flavus and Bcillus subtilis and cultured on the steamed soybean media under various conditions-pH, moisture and temperature were-investigated on the production of aflatoxin by the interaction of these two microorganisms. 1) The amount of aflatoxin produced by mixed cultures of Aspergillus flavus and Bacillus subtilis was decreased significantly rather than that of single cultures of Aspergillus flavus. 2) Maximum production of crude aflatoxin was 2,560 ppm $(B_1,\;0.908\;ppm;\;B_2,\;0.261\;ppm;\;G_1,\;1.162\;ppm;\;G_2,\;0.229\;ppm)$ at 30% moisture, pH 5.0 and $20^{\circ}C$, whereas minimum production was 1.107 ppm $(B_1,\;0.341\;ppm;\;B_2,\;0.104\;ppm;\;G_1,\;532\;ppm;\;G_2,\;0.130\;ppm)$ at 63% moisture, pH 9.0 and $40^{\circ}C$.

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

• Microbiology and Biotechnology Letters
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• v.26 no.6
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• pp.507-514
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• 1998

The strain K-54, the best producer of fibrinolytic enzyme, was isolated from Korean traditional food Chung Guk Jang and identified as Bacillus subtilis. Fibrinolytic enzyme was purified and characterized, and its molecular weight was determined. The fibrinolytic enzyme activity was increased about 66.9 times via purification with recovery yield of 10.1%. The optimum pH and temperature of this enzyme were 11 and $65^{\circ}C$. The enzyme was stable within a pH range 8-12 and unstable at 9$0^{\circ}C$. The molecular weight was estimated to be 29,000 dalton in the form of monomer with no other subunit. The isoelectric point was calculated 8.67. N-terminal sequence was identified Ala-Gly-Ser-Val-Pro-Try-Gly-Ser. Km value of the enzyme for $\alpha$-casein was calculated to be 0.31 (3.1 mg/$m\ell$). The enzyme activity highly inhibited by PMSF at 1 nM.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.6
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• pp.915-921
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• 1996

An alkaline pretense Producing microorganism was isolated from Korean traditional soy sauce and identified as Bacillus subtilis CCKS-111. The optimum culture condition of Bacillus subtilis CCKS-111 for the production of alkaline pretense was as follow: 2% soluble starch, 0.2% peptone, 0.1% (NB$_4$)$_2$S$_2$O$_{8}$ , 0.2% MgSO$_4$, pH 7.0, 35$^{\circ}C$ and 24hrs. The optimum pH and temperature for the enzyme activity of alkaline pretense producing Bacillus subtilis CCKS-111 were pH 9.0 and 5$0^{\circ}C$, respectively. The enzyme was relatively stable at pH 6.0~11.0 and at temperature below 4$0^{\circ}C$. The activity of the enzyme was inhibited by $K^{+}$ and Hg$^{2+}$, whereas Cu$^{2+}$ exhibited rather activating effects on the enzyme activity. Ethylenediaminetetraacetic acid and phenylmethanesulfonyl fluoride inhibited the enzyme activity. This indicates that this is serine pretense which requires metal ion group for the enzyme activity. Km value was 2.313$\times$10$^{-4}$ M/L, V$_{max}$ value was 39.216$\mu\textrm{g}$/min. This enzyme hydrolyzed casein more rapidly than the hemoglobin.lobin.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.326-335
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• 2008

The siderophore ($siderophore_{AH18}$) of Bacillus subtilis AR18 was determined to be one of catechol type and purified by using Amberlite XAD-2, Sephadex LR-20 chromatography, and reversed-phase RPLC. The $Siderophore_{AH18}$ was identified bacillibactin with its structure by GC-MS, $^1H$-NMR, and $^{13}C$-NMR. $Siderophore_{AH18}$ (bacillibactin) had been confirmed its molecular weight of 883 and chemical structure of $(2,3-dihydroxybenzoate-glycine-threonine)_3$. Purified $siderophore_{AH18}$ showed strong biocontrol ability towards the spore of Phytophthora capsici on PDA and able to effectively suppress (55%) P. capsici causing red-pepper blight in the pot in vivo test.

• Microbiology and Biotechnology Letters
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• v.25 no.1
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• pp.62-67
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• 1997

A potential biocontrol bacterium, YB-70 was isolated from a rhizosphere in suppressive soil and identified as a strain of Bacillus subtilis. In several biochemical and in vitro antibiosis tests on Fusarium solani with the culture filterates from B. subtilis YB-70, we found that antifungal mechanism of B. subtilis YB-70 was mediated by antibiotic substances produced from the bacterium. These antifungal substances were appeared to be hear-resistant, micromolecular, and ethy alcohol soluble. Antifungal agents produced by B. subtilis YB-70 showed strong inhibified against root-rotting fungi F. solani in in vivo pot test. An antifungal substance. YBS-1s, was purified from the culture broth of B. subtilis YB-70 by isoelectronic precipitation, silica gel column chromatography and Sephadex LH-20 column chromatography analysis by Fab-MASS, $^{1}$H-NMR, $^{13}$C-NMR, DEPT, and amino acid analyzer revealed that the YBS-1A was a peptide antibiotics of iturin class containing seven amino acids from five different groups, and the other(YBS-1B) was an analogue of iturin group composed of 11 amino acids with larher molecular weight of about 1, 500 dalton, which was lager than that of iturin A.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.178-186
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• 2012

This study was investigated for the purpose of the isolation and identification of antagonistic bacteria with antifungal activity against plant pathogens. This bacteria denominated Bacillus subtilis KYS-10 and the optimum growth condition were 4% sucrose, 1% yeast extract, 0.2% $K_2HPO_4$, pH 7, 150 rpm, $30^{\circ}C$, 8 day. The antifungal activities against nine plant pathogens determined inhibition zone size by diffusion methods. The results, G. zeae (scab) 70 mm and P. grisea KACC 40439 (blast), P. capsici KACC 40177 (phytophthora blight) and C. destructans KACC 41077 (root rot of ginseng) 40~43 mm, and C. gloeosporioides KACC 43520 (ripe rot), C. gloesporioides KACC 40003 (anthracnose), S. shiraiana KACC 41065 (stem rot) and S. shiraiana (mulberry sclerotial disease) 35~39 mm and F. Oxysporum KACC 44452 (bulb rot of ginseng) 28 mm. From these experiment results, author suggest that Bacillus subtilis KYS-10 would be developed as a biological control agent thorough the field experimet in the near future.

• KSBB Journal
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• v.13 no.5
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• pp.491-496
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• 1998

The production of fibrinolytic enzyme from Bacillus subtilis BK-17 was studied in the shake flask cultures. The important medium components studied include nitrogen source, carbon source and inorganic salts. The environmental conditions include initial pH, temperature, shaking speed and working volume. Among various N-sources, C-sources and inorganic salts tested, soybean flour, D-glucose and Na2HPO4 gave the best results, and their optimal concentrations were 1.5%, 0.5% and 0.05%, respectively. The optimal pH and temperature were 9.0 and 37$^{\circ}C$. With decreasing working volume in the range of 25∼100ml in the 250ml flask or increasing shaking speed in the range of 100∼300rpm, the enzyme production was greatly enhanced. The enzyme activity under the optimal conditions was about 1400I.U./ml with urokinase as a standard.

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.339-346
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• 2007

The MJP1 bacterial strain, which possesses antifungal activity, was isolated from meju and identified as Bacillus subtilis based on its morphological and biochemical properties, as well as its 16S rRNA sequence. Antimicrobial activity was found against various species of Gram-positive bacteria, yeasts, and molds, including food-spoilage microorganisms. The antifungal activity was found to be stable after heat and proteolytic enzyme treatment, and in the pH range of $6.0{\sim}10.0$. The antibacterial activity was stable in the pH range of $6.0{\sim}10.0$, but about 50% of the activity was lost after 24 hr at $30^{\circ}C$. The antibacterial compound was also inactivated by proteolytic enzyme treatment, indicating its proteinaceous nature. The apparent molecular masses of the partially purified antifungal and antibacterial compounds, as indicated by using the direct detection method in Tricine-SDS-PAGE, were approximately 2.4 kDa and 4.5 kDa, respectively. These studies suggest that B. subtilis MJP1 produces two bacteriocin-like substances with antifungal and antibacterial activities.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.94-100
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• 2006

To isolate a bacterium that produces plant growth promoting hormone, a total of 29 bacteria were obtained from the soil in Gyeongsan, Korea. Among these, 14 strains were selected by their positive reaction on Salkowski to produce auxin. All of these were then tested for their property to produce siderophore using CAS (chrome azurol S) blue agar, and one was chosen for its ability to produce both, auxin and siderophore. This strain, denoted, AHl8, showed 1.5 times higher adventitious root induction rates than controls, using mung-beans. The strain also showed efficient biocontrol properties towards Fusarium-wilt of tomatoes in artificial pot assays. The strain was identified as Bacillus subtilis by 16s rDNA comparison and Biolog analyses. Growth and media conditions for Bacillus subtilis AH1 8 to highly produce siderophore were also investigated.