• Korean Journal of Food Science and Technology
• /
• v.46 no.2
• /
• pp.165-172
• /
• 2014

Mixed fermentation of cow milk was performed by sequential co-cultures with Bacillus subtilis and Lactococcus lactis. After a first fermentation step with B. subtilis for 6 h, the number of viable cells increased to $2.5{\times}10^8$ CFU/mL. The second fermentation step with L. lactis resulted in increased viable cells $1.09{\times}10^{10}$ CFU/mL for 3 days and increased acidity. However, the number of viable B. subtilis cells was decreased greatly to $5{\times}10^1$ CFU/mL following fermentation with L. lactis. Milk proteins were markedly hydrolyzed by the first fermentation after 2 h, and the second fermentation induced curd formation in milk. However, after 4 h, the first fermentation resulted in higher whey separation and 80 mg% tyrosine content. Gamma-aminobutyric acid (GABA) production was dependent upon the degree of protein hydrolysis by first fermentation. Second fermentation resulted in 0.14% GABA. The milk fermented by B. subtilis indicated the rough surface of yogurt depended upon the degree of protein hydrolysis. In conclusion, set-type yogurt was efficiently produced by co-culturing of milk, and fortifying with peptides, GABA, and probiotics.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.3
• /
• pp.357-363
• /
• 2000

고추장의 품질을 향상시키고 재래식 전통 고추장과 유사한 맛을 지닌 고추장을 만들기 위해 재래식 전통 고추장에서 분리한 B.licheniformis 균주와 공장에서 대량 생산을 위해 개량해온 A. oryzae와, 비교적 호염성이며 알콜 발효 능력이 우수한 S.rouxii를 혼용하여 고추장을 담근 후 180일까지의 각 고추장의 이화학적 특성 변화를 조사한 결과는 다음과 같다. 단도는 모든 구에서 숙성 30일 까지 급격히 증가한 후 180일까지 거의 일정한 수준을 유지하였으며, 곰팡이 단용구에 비해 고초균과 효모 혼용구에서 숙성 기간 동안 높은 적정산도 값을 보였다. 조단백질은 숙성 기간 동안 대조구에서는 숙성 60일까지 약간 증가한 후 숙성 120일까지 급격히 감소하였으며 고초균 혼용구와 효모 첨가구는 숙성 90일 이후 감소한 후 숙성 120일 이후부터는 거의 변화가 없었다. 숙성 90일 이후부터는 B. licheniformis와 효모 혼용구에서 A. oryzae 단용구보다 조단백질 함량이 높았다. 환원당은 세 구간 모두 숙성 60일 경까지는 증가하는 추세를 보였으며, A. oryzae 단용구보다 B.licheniformis 균주와의 혼용구에서 높은 수치를 보여주었다. 비휘발성 유기산은 숙성 기간이 경과하면서 증가하였고 가장 많이 검출된 유기산은 pyroglutamic acid와 citric acid의 순이었다. 따라서 고추장의 숙성 과정 중 이화학적 특성 변화의 측면에서 볼 때 고초균과 효모 혼용구로 제조된 고추장이 구수한 맛의 생성면에서 유용한 담금법인 것으로 사료된다.

• Korean Journal of Microbiology
• /
• v.36 no.3
• /
• pp.203-208
• /
• 2000

A Baczllus circdans KCTC3004 $\alpha$-amylase gene contained in a recombinant plasmid pAL850 was transferred into a new shuttle vector plasmid pALSIlI by ligating linearlzed DNAs of pUC19 and pUB110. B. subtilis RM125 and B. megatenurn ATCC14945 transfonned with pALS111 produced the $\alpha$-amylase substantially Most of the enzyme was produced during the exponential growth period. The maxiinurn activities of the $\alpha$-amylase produced by the Bucillus transformants were compared with that of the B. circulans gene donor strain. The B. subtilis RM125(pALS111) enzyme showed the actlvicy 95 times higher than that of the gene donor cells, followed by the B, nzegaterium ATCC14945(pALSlll) enzyme with activity 34 limes higher than that of the gene donor cells. While E coli secreted about 10% of the produced enzyme, B. subtilis excreted the enzyme inlo the medium wholly and B. megaterirun about 98% ofthe total product. The plasmid pALSI11 was quite stable inB. nzegaterium (92%), inoderately stable in B. subtilis (76%), but was unstable in E. coli (38%). The SDS-PAGE and zymogram of this enzyme produced in E. coli(pALS111), B. subtilis( pALS111) or B. megateril~m (pALS111) indicated a molecular weight of 55,000. The enzymes overproduced in three different host cells hydrolyzed starch to produce mainly maltoaiose and mallooligosaccharides.

• Korean Journal of Food Science and Technology
• /
• v.32 no.2
• /
• pp.410-416
• /
• 2000

Changes in microflora and enzyme activities of three kinds of kochujang were investigated during 6 months of fermentation. Three different kinds of kochujang were prepared using Aspergillus oryzae, Aspergillus oryzae plus Bacillus licheniformis and Aspergillus oryzae, Bacillus licheniformis plus Saccharomyces rouxii. The pH of kochujang showed a slight decrease during fermentation. The number of mold and bacteria increased up to 30 days of fermentation and then decreased rapidly thereafter and the numbers of yeast increased after 30 days of fermentation. The viable cell counts of anaerobic bacteria increased remarkably up to 30 days of fermentation and then decreased to 60 days of fermentation. The activities of ${\alpha}-$, ${\beta}-\;amylase$ and protease were the highest in kochujang prepared with Aspergillus oryzae plus Bacillus licheniformis.

• Korean Chemical Engineering Research
• /
• v.56 no.4
• /
• pp.524-535
• /
• 2018

In this study, macroporous titania powders were synthesized utilizing the emulsion-assisted self-assembly to apply the removal of B. subtilis under UV irradiation, and the results were compared with the bactericidal effect of commercial titania nanoparticles. By changing the pore size of the porous titania powder, the reduction of B. subtilis by photocatalytic effect was measured, and the bactericidal capacity of the porous particles according to the pore size was compared in order to derive the optimum condition of the sterilization experiment. It was observed that the sterilization effect increased as the pore size became smaller, and it was confirmed that more than 50% of B. subtilis cold be removed for 1 hour of UV irradiation. Also, in order to promote the generation of active chemical species, a diluted solution of hydrogen peroxide was combined with the photocatalytic sterilization method, resulting in the removal of most of the strain after ultraviolet irradiation for 1 hour.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.11
• /
• pp.1119-1126
• /
• 2012

The collective behavior of bacteria plays an important role in biofilm development. In this study, the fluidic properties of biofilms formed in Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) colonies were compared by visualizing 200-nm fluorescent beads that were initially embedded in an agar plate and distributed spontaneously on the upper surface of the growing colonies. We conducted experiments to measure the three-dimensional profile of the E. coli colony using fluorescent microbeads that did not flow in the colony. Vortical flow patterns near the edge of the B. subtilis colony were observed clearly by tracking the movement of the beads in the biofilm of the colony. The present study should be the first step toward determining the effect of fluidic biofilms on the growth and swarming dynamics of bacteria.

• Journal of Nutrition and Health
• /
• v.54 no.6
• /
• pp.618-630
• /
• 2021

Purpose: The ginger rhizome (Zingiber officinale) is widely cultivated as a spice for its aromatic and pungent components. One of its constituents, 6-hydroxydopamine (6-OHDA) is usually thought to cross the cell membrane through dopamine uptake transporters, and induce inhibition of mitochondrial respiration and the generation of intracellular reactive oxygen species (ROS). This study examines the neuroprotective effect and acetylcholinesterase (AChE) inhibitory activity of fermented ginger extracts (FGEs) on 6-OHDA induced toxicity in SH-SY5Y human neuroblastoma cells. Methods: Ginger was fermented using 2 species of Bacillus subtilis, with or without enzyme pretreatment. Each sample was extracted with 70% ethanol. Neurotoxicity was assessed by applying the EZ-Cytox cell viability assay and by measuring lactic dehydrogenase (LDH) release. Morphological changes of apoptotic cell nuclei were observed by Hoechst staining. Cell growth and apoptosis of SH-SY5Y cells were determined by Western blotting and enzyme activity analysis of caspase-3, and AChE enzymatic activity was determined by the colorimetric assay. Results: In terms of cell viability and LDH release, exposure to FGE showed neuroprotective activities against 6-OHDA stimulated stress in SH-SY5Y cells. Furthermore, FGE reduced the 6-OHDA-induced apoptosis, as determined by Hoechst staining. The occurrence of apoptosis in 6-OHDA treated cells was confirmed by determining the caspase-3 activity. Exposure to 6-OHDA resulted in increased caspase-3 activity of SH-SY5Y cells, as compared to the unexposed group. However, pre-treatment with FGE inhibited the activity of caspase-3. The neuroprotective effects of FGE were also found to be caspase-dependent, based on reduction of caspase-3 activity. Exposure to FGE also inhibited the activity of AChE induced by 6-OHDA, in a dose-dependent manner. Conclusion: Taken together, our results show that FGE exhibits a neuroprotective effect in 6-OHDA treated SH-SY5Y cells, thereby making it a potential novel agent for the prevention or treatment of neurodegenerative disease.

• Food Science and Preservation
• /
• v.30 no.1
• /
• pp.146-154
• /
• 2023

To develop a multi-functional ingredient, the bioconversion of katsuobushi protein was optimized using Bacillus subtilis HA and Lactobacillus plantarum KS2020. The Dendropanax morbiferus extract (DME) culture with protease activity (102 unit/mL) was prepared by B. subtilis with 2% glucose and 1% skim milk through one day of alkaline fermentation. Katsuobushi protein was effectively hydrolyzed by the DME culture at 60℃ for 3 hours, resulting in a tyrosine content of 156.85 mg%. Subsequently, a second lactic acid fermentation was carried out with 10% monosodium glutamate (MSG) using L. plantarum KS2020 to produce higher levels of GABA. Following co-cultivation for three days, DME exhibited a pH of 8.3 (0% acidity). After seven days, the viable cell count of L. plantarum increased to 9.33 CFU/mL, but viable Bacillus cells were not detected. Taken together, a multi-functional ingredient with enriched GABA, peptides, probiotics, and umami flavor was developed through lactic acid fermentation using hydrolyzed katsuobushi protein. These results indicate that katsuobushi protein could be used as a byproduct to produce a palatable protein hydrolysate using alkaline-fermented DME culture as a proteolytic enzyme source.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.6
• /
• pp.904-909
• /
• 2005

To produce functional food ingredient from the soybean curd residue (SCR), alkaline fermentation was performed with SCR from cold processed (D-SCR) or hot processed (P-SCR) tofu. The solid- state fermentation was performed by Bacillus firmus NA-1 at $42^{\circ}C$. The fermentation of heat-treated D- SCR resulted in higher production of peptides and fibrinolytic enzyme compared with D-SCR without heating. The P-SCR showed higher production of peptides, fibrinolytic enzyme, indicating alkaline pH after fermentation for 18 hr. When the moisture content of P-SCR was reduced to $60\%$, the production of peptides and fibrinolytic enzyme were enhanced. The P-SCR fortified with $10\%$ MFS (micronized full-fat soy flour) showed higher fibrinolytic enzyme activity and consistency index by fermentation of Bacillus firmus NA-1 Furthermore, the P- SCR fortified with $20\%$ MFS indicated relatively higher peptide content, fibrinolytic enzyme activity and enhanced flavor. By increasing the addition of MFS, the peptide content of fermented P-SCR was increased significantly, but fibrinolytic enzyme was slightly decreased.

• Microbiology and Biotechnology Letters
• /
• v.26 no.1
• /
• pp.23-33
• /
• 1998

The entire sequence of a 4,214,810 bp genome of the Bacillus subtilis 168 has been determined by an international project, and the completion has been announced on July 19, 1997. For the sequencing project an international consortium was established and 25 European, 7 Japanese laboratories, 2 biotechnology companies, and our laboratory participated in the project. Within this framework we determined the complete nucleotide sequence of a 53,289 bp fragment upstream of the odhA gene (181 $^{\circ}$) of the B. subtilis 168 chromosome. On the basis of the published DNA sequences of the B. subtilis sspC and odhA genes, we obtained genomic fragments by plasmid rescue and long-range PCR. The sequenced fragment contains 56 putative open reading frames (designated yojA-yolI and 9 known genes (sspC, cge cluster, orfE5, orfRMl and odhA), in which we found many interesting features. In addition, the entire nucleotide sequence of a 53,289 bp region enabled us to revise the current genetic map of this region.