• Journal of Microbiology and Biotechnology
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• v.21 no.5
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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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• v.18 no.5
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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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• v.21 no.3
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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.

• Journal of the Korean Society of Food Culture
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• v.28 no.6
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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.

• Microbiology and Biotechnology Letters
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• v.38 no.2
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• pp.163-167
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• 2010

Bacillus subtilis 168 secreted antimicrobial substance(s) into culture medium and culture supernatant inhibited growth of some Gram positive bacteria. B. cereus and Listeria monocytogenes were the most sensitive organisms. The antimicrobial activity was destroyed when culture supernatant was treated by protease and proteinase K, indicating the proteinous nature of the substance (bacteriocin). The molecular weight of the bacteriocin was estimated to be 5 kDa by Tricine SDS-PAGE. B. cereus ATCC 14579 cells were killed when exposed to the bacteriocin, indicating that the mode of inhibition was bacteriocidal. These results show that B. subtilis 168 could be useful as a starter for fermented foods such as cheonggukjang where B. cereus contamination is a major concern.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.144-145
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• 2017

A Bacillus subtilis strain, designated G24, was isolated from grape during a study on the fermentation of Cheongkukjang, Korean traditional fast-fermented bean paste. Also, a newly isolated bacteriophage SPG24, which was found to inhibit the fermentation process, uses B. subtilis G24 as a host. The complete genome sequence of the bacteriophage SPG24 was 152,060 bp in length, with a G+C content of 42.2%. This sequence included 232 ORF; 58 forward ORFs and 174 reverse ORFs.

• Journal of Microbiology and Biotechnology
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• v.25 no.1
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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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• v.21 no.3
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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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• v.23 no.7
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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.

• The Journal of Korean Obstetrics and Gynecology
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• v.28 no.1
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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.