• 농업과학연구
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• 제34권2호
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• pp.161-170
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• 2007

Poly($\gamma$-glutamic acid) 및 levan의 생성균주로 알려진 Bacillus subtilis BS 62의 $\gamma$-GTP(ggt) 유전자를 해석하기 위하여 PCR 반응에 의해 BS 62의 염색체 DNA로부터 약 2.5 kb의 $\gamma$-GTP(ggt) 유전자 분획을 얻어 그 PCR 산물의 염기서열을 분석하여 기왕에 보고된 기타의 ggt 유전자와 비교 분석한 결과, B. subtilis $\gamma$-GTP 유전자(BSU49358)와 98%의 높은 상동성을 보였으며, Pseudomonas sp. A14(S63255)와는 37%, 방선균인 Streptomyces avermitils(AP005028)의 게놈 DNA와는 38%의 상동성을 나타냈다. BS 62의 $\gamma$-GTP 유전자의 open reading frame은 587개의 amino acid로 구성된 polypeptide의 것으로 해석되었으며, N-terminal의 28개 아미노산은 B. subtilis 펩타이드의 전형적인 형태를 보였고, 전형적인 리보솜의 부착부위는 개시코돈 ATG의 위쪽 7번에서 12번 염기(AGGAGG)에 위치하였고, 그리고 종지코돈 다음에서는 stem-loop 구조, ORF의 위쪽 약 50 bp 지점에서는 catabolite-responsive element가 발견되었다. 또한 B. subtilis 효소의 촉매자리로 추정되는 467번 잔기는 threonine으로서, 다른 박테리아의 serine, 포유동물의 cysteine과는 구별되는 것이었다.

• Journal of Microbiology and Biotechnology
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• 제11권3호
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• pp.428-434
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• 2001

A viscous substance producer strain BS62, which was isolated from conventional Chungkookjang, was examined for its productivity of levansucrase and levan during soybean fermentation at $37{\circ}C$. After one day of cultivation, the enzyme activity reached the highest level, 8 units $ml^{-1}$. Extracts of fermented soybeans were precipitated by ethanol and hydrolyzed by either 0.1 N HCl or invertase, and the hydrolyzates were analyzed using thin layer and ion chromatographies. Fructose was the only sugar detected. This suggest that fructose was derived from the levan produced by the strain BS62 during soybean fermentation. The aerobic, endospore-forming bacterium BS62 was identified as a Bacillus subtilis sp., based on the composition of its cellular fatty acids and phylogeny, which was determined by its 16S rDNA sequence.

• 한국미생물·생명공학회지
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• 제1권1호
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• pp.13-18
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• 1973

Bacillus subtilis의 생균 및 포자액을 자외선 조사와 diethylsulfate 처리로서 adenine 요구변이주 총 62주를 분리하였다. 이들 변이주는 발효배지에 자외선흡수 물질을 축적하고 있음을 확인하였으며 이 축적물은 thin-layer chromatogram 자외선흡수 곡선등으로 hypozanthine, uracil 임을 동정하였다. 이 중에서 hypoxanthine만을 축적하는 변이주 BS-137의 배지성분을 검토한 결과 탄소원소로서는 glucose가 좋았으며 질소원으로서는 yeastext와 NaNO$_3$ 가 적당하였다. 아울러 배양액으로부터 hypoxanthine을 분리 정제하는 방법을 확립하였다.

• Macromolecular Research
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• 제13권4호
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• pp.339-343
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• 2005

Microbial hydrogel was prepared by ${\gamma}-irradiation$ of poly(${\gamma}-glutamic acid$) (PGA) which was produced from Bacillus subtilis BS 62 and it's physico-chemical characteristic was examined. The hydrogel, prepared from 10% PGA with the dose of 48 kGy, was swollen up to 1,370 times of specific water content as dry weight basis. The hydrogels obtained above the dose of 48 kGy appeared to have higher compressive strength but lower specific water content. The period to reach a swelling equilibrium for the hydrogel in deionized water at the temperature range of 4 to $45^{\circ}C$ was about 10 h. The swollen hydrogel was shrunk in ionic solutions with the increase of ionic strength, and the rate of shrinkage was greater in calcium chloride solution than in sodium chloride. Specific water content of the hydrogel was quickly decreased at $80^{\circ}C$, showing a thennally hydrodegradable property.

• 한국환경농학회지
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• 제35권1호
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• pp.62-71
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• 2016

BACKGROUND: Soybeans are the rich sources of isoflavones. To date, the changes of isoflavone contents in various black soybeans cheonggukjang during fermentation by Bacillus subtilis CSY191 has not been investigated.METHODS AND RESULTS: This study investigated the changes of total phenolic and isoflavone contents and antioxidant effects during cheonggukjang fermentation made with four black soybean (BS) cultivars including Cheongja, Cheongja#3, Geomjeong#5, and Ilpumgeomjeong with a potential probiotic Bacillus subtilis CSY191. The total phenolic contents, isoflavone-malonylglycoside and -aglycone contents, and antioxidant activity were increased in cheonggukjang at 48 h fermentation, while the content of isoflavone-glycosides was decreased during cheonggukjang fermentation. In particular, the Cheongja#3 soybean fermented at 37℃ for 48 h displayed the highest antioxidant activities, compared to those of the other BS cultivars tested. Also, the highest levels of total phenolic, daidzein, glycitein, and genistein were present at concentrations of 17.28 mg/g, 283.7 g/g, 39.9 g/g, and 13.2 g/g at the end of Cheongja#3 soybean fermentation.CONCLUSION: The results from this study suggested that the enhanced antioxidant activity of cheonggukjang of BS might be related to increased levels of total phenolic, isoflavon-aglycone, and malonyl-glycoside contents achieved during fermentation. Furthermore, fermented Cheongja#3 soybean showed the highest levels of enhanced antioxidant activities than the other BS cultivars.

• Journal of Applied Biological Chemistry
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• 제48권4호
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• pp.213-217
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• 2005

Microbial hydrogel was prepared with poly(${\gamma}$-glutamic acid) produced from Bacillus subtilis BS62 using crosslinking reagent, ethylene glycol diglycidyl ether (EGDE), and its physico-chemical characteristics were examined. Hydrogel which prepared from 10 grams of 10% PGA solution with $600\;{\mu}l$ of EGDE at $50^{\circ}C$ for 17 h swelled 4,320 times its dry weight, and time to reach swelling equilibrium in deionized water at 4 to $45^{\circ}C$ range was about 20 h. Swollen hydrogel shrunk in ionic solutions, and rate of shrinkage was higher in calcium chloride solution than sodium chloride solution. Swelling rate of hydrogel increased 1.3-fold of initial swelling rate for 30 min at $80^{\circ}C$.