• Journal of Microbiology and Biotechnology
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• 제21권5호
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• pp.515-518
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• 2011

A gene encoding bacillopeptidase F, bpr86-1, was cloned from B. amyloliquefaciens CH86-1 isolated from cheonggukjang. This gene could encode a preproenzyme of 1,431 amino acids. When bpr86-1 was introduced into B. subtilis WB600 via pHY300PLK, an E. coli-Bacillus shuttle vector, the transformant showed fibrinolytic activity. During growth on LB, the fibrinolytic activity of cells increased sharply when they entered the stationary phase. The highest activity (761.4 mU/mg protein) was observed at 96 h of cultivation.

• Food Science and Biotechnology
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• 제18권5호
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• pp.1298-1300
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• 2009

To develop a dietary beverage with functionalities of cheonggukjang, soymilk was fermented with Bacillus subtilis and its antioxidant activities were examined. Antioxidative capacities of fermented soymilk (FS) with 5 different B. subtilis were significantly different. Among these, FS with 2829PNU015 revealed the greatest antioxidant activities. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, total antioxidant activity, and low density lipoprotein (LDL) oxidation inhibition of FS with 2829PNU015 were increased by 150, 140, and 240%, respectively, compared with those of unfermented soymilk (p<0.05). Further study for the improvement of sensory properties of FS with B. subtilis is required for a commercial production.

• Journal of Microbiology and Biotechnology
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• 제21권3호
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• pp.274-276
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• 2011

Distinction of Bacillus cereus from other closely related bacilli is challenging and new efficient methods are continually demanded. From our previous work on RAPD profiles of bacilli, we found a possibility that B. cereus strains could be distinguished from other bacilli. In this work, RAPD-PCR profiles of B. cereus strains were obtained using a 10-mer (S30) as a primer, and a B. cereus specific 0.91-kb band was produced from all tested strains. The RAPD-PCR procedure also successfully detected B. cereus from spiked cheonggukjang when B. cereus cells were present at more than $10^2$/g sample.

• 한국식생활문화학회지
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• 제28권6호
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• pp.640-650
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• 2013

Soy sauce, a basic ingredient in Asian cuisine, is made of fermented soybeans, salt, water, and barley or wheat flour. The sensory characteristics of soy sauce are not only determined through its main ingredients but also by various flavor compounds produced during the fermentation process. This study was conducted to identify the sensory attributes of five different commercial soy sauce samples that differ in Meju types (traditional Meju or modified Meju) and usage types. Thirty three sensory attributes, including appearance (1), odor (16), flavor (14), and mouthfeel (2) attributes, were generated and evaluated by eight trained panelists. The collected data were analyzed by analysis of variance and principal component analysis. There were significant differences in the intensities of all sensory attributes among the soy sauce samples. Soy sauce made with traditional Meju had high intensity of fermented fish, beany, musty odors and salt, Cheonggukjang, fermented fish flavors. Whereas two soy sauces made with modified Meju were strong in alcohol, sweet, Doenjang, roasted soybean flavors. Two soy sauces for soup made with modified Meju had medium levels of briny, sulfury, fermented odors and bitter, chemical flavors and biting mouthfeel characteristic.

• 한국미생물·생명공학회지
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• 제38권2호
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• pp.163-167
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• 2010

B. subtilis 168 균주는 배양중 항균물질을 배지중으로 분비하며 배양상등액은 몇몇 그램 양성균을 저해한다. B. cereus와 L. monocytogenes의 저해 정도가 가장 컸었다. 배양상등액을 proteas와 proteinase K로 처리할 경우 항균력이 상실되어서 항균물질은 단백질성(박테리오신) 임을 알수있었다. Tricine SDS-PAGE에 의해서 박테리오신 분자량은 5 kDa으로 확인되었다. 박테리오신은 민감한 균을 죽임으로써 생육을 저해하는 것으로 밝혀졌다. 이상 결과들에서 B. subtilis 168은 청국장과 같은 B. cereus 오염이 문제되는 발효식품들의 종균으로 유용할 것으로 생각된다.

• 미생물학회지
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• 제53권2호
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• pp.144-145
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• 2017

Bacillus subtilis를 이용하여 청국장 발효 연구를 진행하던 중 발효능이 뛰어난 B. subtilis G24라는 균주를 새로 분리하였고, 이를 숙주로 이용하는 bacteriophage SPG24를 새로 분리하였다. 본 연구에서는 bacteriophage SPG24의 유전체 서열을 해독하였으며 전체길이 152,060 bp, G+C 함량 42.2%, 232개 ORF의 bacteriophage SPG24는 B. subtilis G24를 숙주로 이용함으로써 청국장 발효를 저해하는 것으로 확인되었다.

• Journal of Microbiology and Biotechnology
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• 제25권1호
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• pp.89-97
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• 2015

Bacillus subtilis HK176 with high fibrinolytic activity was isolated from cheonggukjang, a Korean fermented soyfood. A gene, aprE176, encoding the major fibrinolytic enzyme was cloned from B. subtilis HK176 and overexpressed in E. coli BL21(DE3) using plasmid pET26b(+). The specific activity of purified AprE176 was 216.8 ± 5.4 plasmin unit/mg protein and the optimum pH and temperature were pH 8.0 and 40℃, respectively. Error-prone PCR was performed for aprE176, and the PCR products were introduced into E. coli BL21(DE3) after ligation with pET26b(+). Mutants showing enhanced fibrinolytic activities were screened first using skim-milk plates and then fibrin plates. Among the mutants, M179 showed the highest activity on a fibrin plate and it had one amino acid substitution (A176T). The specific activity of M179 was 2.2-fold higher than that of the wild-type enzyme, but the catalytic efficiency (k_cat/K_m) of M179 was not different from the wild-type enzyme owing to reduced substrate affinity. Interestingly, M179 showed increased thermostability. M179 retained 36% of activity after 5 h at 45℃, whereas AprE176 retained only 11%. Molecular modeling analysis suggested that the 176^th residue of M179, threonine, was located near the cation-binding site compared with the wild type. This probably caused tight binding of M179 with Ca²⁺, whichincreased the thermostability of M179.

• Preventive Nutrition and Food Science
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• 제21권3호
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• pp.221-226
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• 2016

A new type of doenjang was manufactured by mixing soaked soybean, koji (Rhizopus oryzae), cheonggukjang (Bacillus amyloliquefaciens MJ1-4 and B. amyloliquefaciens EMD17), and Pichia farinosa SY80 as a yeast, salt, and water, followed by fermentation with koji that was made by fermenting whole wheat with R. oryzae. The mixed culture doenjang was designed to have a more palatable flavor and stronger biological activities than the conventional product. The extract of mixed culture doenjang showed higher antioxidant activity than the commercial doenjang as evaluated by the ferric reducing antioxidant power assay although it was not significantly different from the commercial product in 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activities. Further, the mixed culture doenjang reduced intracellular reactive oxygen species levels and protected cells from glutamate-induced cytotoxicity more efficiently in human hippocampal HT22 neuroblastoma cells than the commercial doenjang. In conclusion, a newly-developed mixed culture doenjang had a strong antioxidant activity in vitro and cultured cell model systems, exhibited a potential to prevent oxidative stress-associated disorders although animal and clinical studies are needed to confirm its in vivo efficacy.

• Journal of Microbiology and Biotechnology
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• 제23권7호
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• pp.974-983
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• 2013

Bacillus amyloliquefaciens CB1 was isolated from cheonggukjang, a Korean fermented soy food. B. amyloliquefaciens CB1 secretes proteases with fibrinolytic activities. A gene homologous to aprE of Bacillus subtilis, aprECB1, was cloned from B. amyloliquefaciens CB1, and DNA sequencing showed that aprECB1 can encode a prepro-type serine protease consisting of 382 amino acids. When aprECB1 was introduced into B. subtilis WB600 using an E. coli-Bacillus shuttle vector, pHY300PLK, transformants showed fibrinolytic activity and produced a 28 kDa protein, the size expected for the mature enzyme. The 28 kDa fibrinolytic enzyme was purified from the culture supernatant of B. subtilis WB600 transformant. AprECB1 was completely inhibited by phenylmethylsulfonyl fluoride and almost completely inhibited by EDTA and EGTA, indicating that it is a serine metalloprotease. AprECB1 exhibited the highest specificity for N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, a known substrate for ${\alpha}$-chymotrypsin. $A{\alpha}$ and $B{\beta}$ chains of fibrinogen were quickly degraded by AprECB1, but the ${\gamma}$-chain was resistant.

• 대한한방부인과학회지
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• 제28권1호
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• pp.58-72
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• 2015

Objectives: The purpose of this study was to examine the effects of fermented soybean on body weight, body fat, serum lipid profiles in obese women, especially specific to menopausal woman. Methods: Sixty healthy obese volunteers who visited ${\bigcirc}{\bigcirc}$ University Oriental Hospital from May 20th, 2014 to September 25th, 2014 took part in clinical trial. They divided into 2 groups, 30 volunteers allocated to fermented soybean and other 30 to placebo group. Body weight, BMI, waist and hip ratio, serum lipid were measured 3 times, and fat percentage, leptin, adiponectin were evaluated 2 times. Results: All 60 volunteers completed 12-week trial. 5 men were excluded, and 2 women against the clinical decision rule were excluded. In the end, 53 women were studied as clinical subjects. After 12 weeks intervention, there was no effects in comparison of group by time interaction. Without considering time interaction, there was a significant difference in triglyceride level between soybean group and placebo group (p=0.044). Treatment group were dividing by age 40, a group in age 40 or over 40, and other group aged below 40. There was a significant difference in group by time interaction of total cholesterol level, and without considering time interaction, there was a significant change in waist-hip ratio between groups. Conclusions: There were no effects on weight and body fat decrease in 12-week trial using fermented soybean as a supplement. But there were significant differences in triglyceride change between the treatment and placebo groups, also cholesterol and waist and hip ratio in soybean group divided by age 40. It seems that fermented soybean is effected on improving serum lipid profiles.