• Food Science and Preservation
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• v.24 no.7
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• pp.975-982
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• 2017

Health of human intestine has deteriorated due to excessive stress and western diet. In this study, Vigna angularis was fermented by Bacillus subtilis KCCM11965P in order to develop prebiotic resource for improving bowel movement. The contents of ash and crude protein were $3.35{\pm}0.04%$ and $21.1{\pm}0.19%$ respectively. Vigna angularis extract (1, 3, 5%) were incubated with 3% (v/v) Bacillus subtilis KCCM 11965P for 0, 24, 48, and 72 h. Total bacterial numbers showed that the combination of 3% powdered seeds and 72 h incubation time was optimum condition for this experiment. Total polyphenol content increased from $0.18{\pm}0.010mg/mL$ in pre-incubation to $0.23{\pm}0.007mg/mL$ in post-incubation with the condition mentioned above. DPPH radical scavenging activity also increased from $36.1{\pm}6.0%$ to $63.6{\pm}5.2%$. Analysis of protease activity showed $2.69{\pm}0.003unit/mL$ in combination of 5% powdered seeds and 72 h incubation time. Amylase activity increased from $1.0{\pm}0.1unit/mL$ in pre-incubation to $26.0{\pm}0.2unit/mL$ in post-incubation. The analysis of free amino acids after incubation with Bacillus subtilis KCCM 11965P showed that leucine increased from 5.22 mg/L to 67.59 mg/L and tyrosine, one of non-essential amino acid also increased 10.08 mg/L to 259.35 mg/L by incubation with 5% powdered seeds. Most of organic acid were reduced by incubation for 72 h. These results suggest that Vigna angularis could be utilized most as a prebiotic resources.

• Journal of Life Science
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• v.28 no.7
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• pp.827-834
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• 2018

In this study, the biological activities of aqueous, ethanol, and methanol extracts of larvae of the edible insect Protaetia brevitarsis seulensis, fermented using several kinds of microorganisms, were tested in in vitro experimental models. Six effective microorganisms were used for fermentation, namely Lactobacillus plantarum JBMI F3, Lactobacillus plantarum JBMI F5, Lactobacillus gasseri Ba9, Aspergillus kawachii KCCM 32819, Saccharomyces cerevisiae KACC 93023, and Bacillus subtilis KACC 91157. Biological activities (${\alpha},{\alpha}^{\prime}-diphenyl-{\beta}-picrylhydrazyl$ [DPPH] free radical scavenging activity, reducing power, and fibrinolytic activity), and biochemical properties (phenolic compounds and flavonoids) were examined in aqueous, ethanol, and methanol extracts from P. brevitarsis seulensis powder and fermented P. brevitarsis seulensis powder. The total phenolic compounds and flavonoid contents were highest in the aqueous extract of B. subtilis-fermented P. brevitarsis seulensis powder. DPPH radical scavenging activity and reducing power were stronger in the fermented group than the nonfermented group. Fibrinolytic activity were highest in the extract from B. subtilis-fermented P. brevitarsis seulensis powder. The ${\alpha}-amylase$ activity in starch was higher in the fermented group than the nonfermented group, but there was no significant difference. These results provide basic data to understand the biological activities of bioactive materials derived from fermented P. brevitarsis seulensis larvae for the development of functional foods.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.1999-2009
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• 2017

The secretion efficiency of a protein in a Sec-type secretion system is mainly determined by an N-terminal signal peptide and its combination with its cognate protein. Five signal peptides, namely, two synthetic Sec-type and three Bacillus licheniformis alpha-amylase-derived signal peptides, were compared for periplasmic expression of the human growth hormone (hGH) in E. coli. Based on in silico predictions on the signal peptides' cleavage efficiencies and their corresponding mRNA secondary structures, a number of amino acid substitutions and silent mutations were considered in the modified signal sequences. The two synthetic signal peptides, specifically designed for hGH secretion in E. coli, differ in their N-terminal positively charged residues and hydrophobic region lengths. According to the mRNA secondary structure predictions, combinations of the protein and each of the five signal sequences could lead to different outcomes, especially when accessibility of the initiator ATG and ribosome binding sites were considered. In the experimental stage, the two synthetic signal peptides displayed complete processing and resulted in efficient secretion of the mature hGH in periplasmic regions, as was demonstrated by protein analysis. The three alpha-amylase-derived signal peptides, however, were processed partially from their precursors. Therefore, to achieve efficient secretion of a protein in a heterologous system, designing a specific signal peptide by using a combined approach of optimizations of the mRNA secondary structure and the signal peptide H-domain and cleavage site is recommended.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.149-152
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• 2006

Leuconostoc mesenteroides SY1, a strain isolated from cabbage Kimchi, was transformed with pCW4, a shuttle vector based on a cryptic plasmid from Lactobacillus paraplantarum C7. $\alpha-Amylase$ gene, amyL, from Bacillus licheniformis was cloned into pCW4, resulting in $pCW4T{\alpha},\;and\;pCW4T{\alpha}$ was introduced into SY1 by electroporation. Transformation efficiency was $10^2cells/{\mu}g$ plasmid DNA. L. mesenteroides cells harboring $pCW4T{\alpha}$ did not show amylase activity, although amyL transcript was synthesized as determined by slot blot experiment. $pCW4T{\alpha}$ was stably maintained in SY1 in the presence of erythromycin (Em, $5\;{\mu}g/ml$) but rapidly lost when Em was omitted. Less than $1\%$ of the cells maintained $pCW4T{\alpha}$ after 5 days at $30^{\circ}C$.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.3
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• pp.126-131
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• 2002

For the probiotic feed production from residual food waste, aerobic liquid fermentation was conducted by thermophilic bacteria. 11 Strains of bacteria were isolated from several soil sources and residual food waste. Screening was carried by shaking incubator for the separation of thermophilic strain at $55^{\circ}C$. The isolated strains were tested for enzyme activities such as ${\alpha}$-amylase and protease. 6 Bacterial strains were chosen and were adapted by repeated fermentation processes in food waste substrate. The viable cell count of them at final fermentation stages were shown as $3-7{\times}10^9/ml$ in 2L-jar fermenter. Among them B3, B6 showed higher enzyme activity. By the mixed fermentation of B3, B6 and Bacillus stearothermophilus, the highest viable cell count reached to $1.4{\times}10^{10}/ml$ in 8 hours.

• Microbiology and Biotechnology Letters
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• v.38 no.1
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• pp.84-92
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• 2010

Antibacterial compound from Bacillus subtilis MJP1 was purified using C18 Sep-Pak cartridge, ion exchange chromatography, and gel filtration chromatography. The purified antibacterial compound showed antibacterial activity against Listeria monocytogenes, Bacillus subtilis, Staphylococcus aureus subsp. aureus, and Enterococcus faecalis. The purified antibacterial compound was found to be stable at $100^{\circ}C$ for 5 min and in the pH range of 3.0~9.0, but it was unstable at pH 10.0. It was inactivated by proteinase K and pronase E, and heat treatment at $121^{\circ}C$ for 15 min, but it was stable with lipase and $\alpha$-amylase treatment, which indicated its proteineous nature. Ultra performance liquid chromatography and electrospray ionization tandem mass spectrometry analysis were used to identify the purified antibacterial compound and confirmed the existence of two peptides (3356.54 Da, 3400.5244 Da).

• Journal of Life Science
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• v.23 no.4
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• pp.529-536
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• 2013

This study was carried out to investigate the characteristics of white soybean Chungkookjang fermented by Bacillus subtilis D7. The highest germination rate was obtained under $25^{\circ}C$ when water was supplied for 4 days at intervals of 2 hr. The total isoflavone content was 971.3 ${\mu}g/g$ before germination and 1023.8 ${\mu}g/g$ after germination. The amino type- and ammonia type-nitrogen contents of Chungkookjang were proportional to the fermentation time. The pH values of all Chungkookjang soybeans increased up to pH 7.8-8.0 during fermentation. The number of viable cells in all Chungkookjang soybeans increased significantly up to 24 hr. The protease activity of all Chungkookjang soybeans increased up to 30-36 hr. The ${\alpha}$- and ${\beta}$-amylase activities of Chungkookjang fermented by B. subtilis D7 were enhanced with increasing fermentation time. Analysis of the effect of Chungkookjang intake on the liver function of mouse showed that the alkaline phosphatase (ALP) activity and the superoxide dismutase (SOD) activity in the Chungkookjang diet group were markedly higher than those in the control group. The asparatate aminotransferase (AST) activity in the germinated soybean Chungkookjang diet group was higher than that in the nongerminated soybean Chungkookjang diet group. Therefore, Chungkookjang soybeans fermented with B. subtilis D7 can be expected to have an increased content of functional components and improved quality characteristics.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.1025-1030
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• 2006

In other to develop new functional doenjangs, two types of the isolated nuruk doenjangs were prepared with protease and amylase-producing Aspergillus oryzae D-2 and antihyperlipidemia Bacillus subtilis LK-12 and then changes of its quality and physiological functionalities were investigated during 2 months of fermentation and compared with those of the commercial nuruk doenjangs made by commercial Aspergillus oryzae and antihyperlipidemia Bacillus subtilis LK-12. ${\alpha}-Amylase$ activity of the isolated nuruk doenjangs during fermentation were decreased slightly, whereas proteases activities were increased significantly to $1.8{\sim}2.8$ Unit per mL after 1 month of fermentation. These ${\alpha}-amylase$ activities and proteases activities were similar with those of the commercial nuruk doenjangs. Amino-nitrogen content and reducing sugar content of the doenjangs after 2 months of fermentation were approximate $1.63{\sim}1.72\;mg%$ and $0.77{\sim}0.81%$, respectively. Antihypertensive angiotensin-Ⅰ converting enzyme inhibitory activities of the isolated nuruk doenjangs were slightly decreased from $85.6{\sim}87.2%$ to $84.0{\sim}85.1%$ after 2 months of fermentation and the commercial nuruk doenjangs were also significantly decreased from $85.7{\sim}88.0%$ to $69.1{\sim}79.7%$, lower than the isolated nuruk doenjangs. Fibrinolytic activity and HMG-CoA reductase inhibitory activity of the isolated nuruk doenjangs were very low and it were also similar with those of the commercial nuruk doenjangs. Antioxidant activity of the isolated nuruk doenjangs were showed $17{\sim}22%$, lower than that of the commercial nuruk doenjangs $(22{\sim}26%)$.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1799-1808
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• 2006

A food-grade integration vector based on site-specific recombination was constructed. The 5.7-kb vector, pIMA20, contained an integrase gene and a phage attachment site originating from bacteriophage A2, with the ${\alpha}$-galactosidase gene from Lactobacillus plantarum KCTC 3104 as a selection marker. pIMA20 was also equipped with a controllable promoter of nisA ($P_{nisA}$) and a signal peptide-encoding sequence of usp45 ($SP_{usp45}$) for the production and secretion of foreign proteins. pIMA20 and its derivatives mediated site-specific integration into the attB-like site on the Lactococcus lactis NZ9800 chromosome. The vector-integrated recombinant lactococci were easily detected by the appearance of blue colonies on a medium containing $X-{\alpha}-gal$ and also by their ability to grow on a medium containing melibiose as the sole carbon source. Recombinant lactococci maintained these traits in the absence of selection pressure during 100 generations. The ${\alpha}-amylase$ gene from Bacillus licheniformis, lacking a signal peptide-encoding. sequence, was inserted downstream of $P_{nisA}\;and\;SP_{usp45}$ in pIMA20, and the plasmid was integrated into the L. lactis chromosome. ${\alpha}-Amylase$ was successfully produced and secreted by the recombinant L. lactis, controlled by the addition and concentration of nisin.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.549-554
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• 2006

To standardize a manufacturing method and improve the quality of traditional kochujang, eight-types of meju with different shapes (brick, grain) were prepared using Aspergillus oryzae (A.o) or Aspergillus sojae (A.s) alone or in combination with Bacillus subtilis (B.s). The physicochemical characteristics and enzyme activities of the various meju were compared during fermentation for 12 days at $28^{\circ}C$. The moisture content of both the brick- and grain-shaped meju were gradually decreased from an initial content of 50.47 to 54.89% to a content of 12.91 to 16.25% on day 12 of fermentation. The neutral protease activities of the brick-shaped meju ranged from $1.19{\pm}0.12$ to $1.25{\pm}0.28\;unit/mL$, and were similar for all treatments. The ${\alpha}$-amylase activities in A.s+B.s treatment of brick-shaped and grain-shaped meju were the highest, $11{\pm}0.6$ and $9{\pm}0.7\;unit/mL$, respectively. The ${\beta}$-amylase activities ranged from $1.53{\pm}0.01$ to $1.56{\pm}0.02\;unit/mL$, and were similar for all treatments. The amino type nitrogen content of A.o+B.s brick-shaped meju was the highest, $0.39{\pm}0.03%$. We confirmed that the brick-shaped meju prepared with A. oryzae and B. subtilis could be used to prepare traditional kochujang to improve the quality of the product.