• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.846-851
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• 1998

Characteristics of chunggugjang fermented by Bacillus subtilis DC-2, a pigment producing bacterium, were investigated. More water soluble browning materials were produced with fermentation time. The pH was gradually alkalized. The contents of amino nitrogen were extraordinarily increased with fermentation time. Both strength and hardness were gradually decreased during fermentation. Total 30 volatile compounds were identified in the chunggugjang fermented by B. subtilis DC-2. The pyrazines were detected more than any other compounds. The good aroma of the chunggujang fermented by B. subtilis DC-2 was considered to be contributed by tetramethylpyrazine, trimethylpyrazine, 1-octen-3-ol, 2, 5-dimethylpyrazine and guaiacol.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.620-624
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• 1997

The conditions for color intensity and electron donating ability to $\alpha$,$\alpha$-diphenyl-$\beta$- picryl-hydrazyl (DPPH) of Bacillus subtilis DC-2 were investigated. Temperature, pH and cultivation time were chosen as three factors, and the optimal conditions of color intensity and DPPH was determined with response surface methodology. Color intensity was affected by cultivation temperature(p<0.1). DPPH was influenced by cultivation temperature(p<0.05) and pH(p<0.1). But cultivation time was affected neither color in- tensity nor DPPH. Optimal conditions of color intensity with Bacillus subtilis DC-2 were appeared at cultivation temperature of 39.$25^{\circ}C$, pH 8.83 and cultivation time of 84.41hrs. Optimal conditions of DPPH with Bacillus subtilis DC-2 were revealed at cultivation temperature of 39.19$^{\circ}C$, pH 8.84 and cultivation time of 82.21hrs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.840-845
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• 1998

This study was conducted to produce the high quality of chunggugjang. The taste compounds of chunggugjang produced with Bacillus subtilis DC-2, pigment producing bacterium, were analysed, and palatability of chunggugjang was compared to that of commercial chunggugjang. Among the volatile organic acids, the contentof acetic acid was contained more than any other volatile organic acid. The major nonvolatile organic acid was lactic acid, followed by oxalic acid and citric acid. Tartaric acid was not detected. In case of free sugars, raffinose was sharply decreased between 72 and 96 hours after fermentation. Free amino acid was increased to 20 folds at 48 hours after fermentation compared to that of stemed soybean. As a result of sensory test, it was founded that the chunggujang fermented by Bacillus subtilis DC-2 was suitable to produce for commercial purpose.

• 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.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.280-286
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• 2007

We evaluated a commercial biopreparation of plant growth-promoting rhizobacteria (PGPR) strains Bacillus subtilis GB03 and B. amyloliquefaciens IN937a formulated with the carrier chitosan (Bio Yield) for its capacity to elicit growth promotion and induced systemic resistance against infection by Cucumber Mosaic Virus (CMV) and Pseudomonas syringae pv. tomato DC3000 in Arabidopsis thaliana. The biopreparation promoted plant growth of Arabidopsis hormonal mutants, which included auxin, gibberellic acid, ethylene, jasmonate, salicylic acid, and brassinosteroid insensitive lines as well as each wild-type. The biopreparation protected plants against CMV based on disease severity in wild-type plants. However, virus titre was not lower in control plants and those treated with biopreparation, suggesting that the biopreparation induced tolerance rather than resistance against CMV. Interestingly, the biopreparation induced resistance against CMV in NahG plants, as evidenced by both reduced disease severity and virus titer. The biopreparation also elicited induced resistance against P. syringae pv. tomato in the wild-type but not in NahG transgenic plants, which degrade endogenous salicylic acid, indicating the involvement of salicylic acid signaling. Our results indicate that some PGPR strains can elicit plant growth promotion by mechanisms that are different from known hormonal signaling pathways. In addition, the mechanism for elicitation of induced resistance by PGPR may be pathogen-dependent. Collectively, the two-Bacilli strain mixture can be utilized as a biological inoculant for both protection of plant against bacterial and viral pathogens and enhancement of plant growth.