• Journal of Korean Medicine for Obesity Research
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• v.15 no.2
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• pp.123-130
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• 2015

Objectives: Samjung-hwan (SJH), a well-known traditional fermented herb formula recorded in Dongui Bogam, has been commonly used for prolonging life for four hundred years in Eastern Asia. However, fermented SJH has not been investigated in terms of microbial ecology until present time. Methods: SJH was fermented for five weeks and fermentation characteristics during SJH fermentation were performed including pH, acidity and microbial profiling. Also, we measured total polyphenol and total flavonoid contents and 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. In order to select starter candidate, several lactic acid bacteria were isolated from fermented SJH. Results: pH of fermented SJH was decreased from 4.7 to 3.0 and acidity was increased from 0.45% to 1.72%. Also, fermented SJH increased antioxidant indicator such as total polyphenol and total flavonoid as well as DPPH free radical scavenging activity. Lactobacillus brevis was increased, Pseudanabaena sp. was decreased, and Lactococcus lactis subsp. lactis was stable during 5-week fermentation of SJH. L. brevis and L. plantarum were isolated from fermented SJH. Conclusions: Fermented SJH for four weeks had optimal effect on antioxidant and fermentation characteristics such as pH, acidity and microbial profile. Further studies are required to develop starter and analyze functional compounds in oder to produce standardized SJH.

• Journal of Microbiology and Biotechnology
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• v.29 no.10
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• pp.1580-1590
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• 2019

Capsaicinoids in red pepper powder are known to show anti-bacterial effects; however, their effects during kimchi fermentation are not known. This study aimed to investigate the effects of various concentrations of capsaicinoids on kimchi fermentation. Five sets of kimchi samples were prepared using 0 mg/kg (control), $98.34{\pm}5.34mg/kg$ (mild), $243.47{\pm}3.71mg/kg$ (medium), $428.63{\pm}30.78mg/kg$ (hot), and $1,320.49{\pm}28.27mg/kg$ (extreme) capsaicinoid. The characteristics of each kimchi sample, including pH, acidity, organic acid, sugars, sugar alcohol, capsaicinoid content, and microbial community were periodically investigated during fermentation. Kimchi with red pepper powder shows significantly higher acidity than control kimchi, whereas pH values were the same. Organic acid in kimchi with red pepper powder was higher than in control kimchi, probably caused by higher lactic acid bacteria (LAB) counts in kimchi samples with red pepper powder. Our results show that addition of red pepper powder decreased Leuconostoc spp. counts in the bacterial community. In particular, Lactobacillus sakei and Leuconostoc gelidum counts increased and decreased, respectively, with increasing capsaicinoid content of red pepper powder added to kimchi. Overall, the results of this study indicate that physicochemical properties and LAB such as L. sakei and L. gelidum are influenced by capsaicinoid content. However, further studies are necessary to investigate the effects of the percentage of red pepper powder in kimchi on fermentation to provide practical guidelines for producing standardized kimchi.

• Journal of Microbiology and Biotechnology
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• v.31 no.11
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• pp.1552-1558
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• 2021

The diverse microbial communities in kimchi are dependent on fermentation period and temperature. Here, we investigated the effect of enterotoxigenic Escherichia coli (ETEC) during the fermentation of kimchi at two temperatures using high-throughput sequencing. There were no differences in pH between the control group, samples not inoculated with ETEC, and the ETEC group, samples inoculated with ETEC MFDS 1009477. The pH of the two groups, which were fermented at 10 and 25℃, decreased rapidly at the beginning of fermentation and then reached pH 3.96 and pH 3.62. In both groups, the genera Lactobacillus, Leuconostoc, and Weissella were predominant. Our result suggests that microbial communities during kimchi fermentation may be affected by the fermentation parameters, such as temperature and period, and not enterotoxigenic E. coli (ETEC).

• Biotechnology and Bioprocess Engineering:BBE
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• v.2 no.2
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• pp.101-104
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• 1997

Lactic acid production from ${\alpha}$-cellulose by simultaneous saccharification and fermentation (SSF) was studied. The cellulose was converted in a batch SSF using cellulase enzyme Cytolase CL to produce glucose sugar and Lactobacillus delbrueckii to ferment the glucose to lactic acid. The effects of temperature, PH, yeast extract loading, and lactic acid inhibition were studied to determine the optimum conditions for the batch processing. Cellulose was converted efficiently to lactic acid, and enzymatic hydrolysis was the rate controlling step in the SSF. The highest conversion rate was obtained at 46$^{\circ}C$ and pH 5.0. The observed yield of lactic acid from ${\alpha}$-cellulose was 0.90 at 72 hours. The optimum pH of the SSF was coincident with that of enzymatic hydrolysis. The optimum temperature of the SSF was chosen as the highest temperature the microoraganism could withstand. The optimum yeast extract loading was found to be 2.5g/L. Lactic acid was observed to be inhibitory to the microorganisms' activity.

• Microbiology and Biotechnology Letters
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• v.22 no.6
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• pp.700-706
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• 1994

Lactic acid bacteria in Kimchi fermentation were tested for inhibitory activity against Gram positive bacteria and Gram negative bacteria. The Lactobacillus brevis (KCCM 35464) was found to produce a antimicrobial substance. It showed relatively wide range of inhibition spectrum against gram positive and gram negative bacteria and maintained the inhibitory activity between pH 4.0 and pH 9.0. The antimicrobial substance was obtained in the stationary growth phase and was purified by gel chromatography. The inhibitory effect of the antimicrobial substance on sensitive bacterial strains was determined by filter paper test. The activity of antimicrobial substa- nce was stable at 75$\circ$C. On the basis of its electrophoretic pattern is SDS-PAGE, antimicrobial substance appeared as a single band of 59 KDalton.

• Microbiology and Biotechnology Letters
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• v.27 no.2
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• pp.113-117
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• 1999

As a basic study for quality improvement of Korean soybean paste and soybean sauce, we investigated on microflora of soybean paste and soybean sauce fermentation. Major Microorganisms were isolated from the sample pastes and sauces, and identified systematically. Selected Microorganisms were identified by MIS whole cell fatty acid analysis by gas chromatography. Identification results showed that Bacillus licheniformis, bacillus pumilis and Bacillus subtilis were dominant in soybean paste and Staphylococcus vitulus, Bacillus subtilis, Bacillus pumilus, and Lactobacillus fermentum were dominant in soybean sauce. It seemed that these Microorganisms played an important role in soybean paste and soybean sauce fermentation and could be used for the further studies such as protease and amylase activities.

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1725-1725
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• 2017

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.6
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• pp.819-827
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• 2017

Objective: Four lactic acid bacteria (LAB) strains isolated from common vetch, tall fescue and perennial ryegrass on the Tibetan Plateau were characterized, and their effects on the fermentation quality of Italian ryegrass (Lolium multiflorum Lam.) silage were studied. Methods: The four isolated strains and one commercial inoculant (G, Lactobacillus plantarum MTD-1) were evaluated using the acid production ability test, morphological observation, Gram staining, physiological, biochemical and acid tolerance tests. The five LAB strains were added to Italian ryegrass for ensiling at three different temperatures ($10^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$). Results: All isolated strains (LCG3, LTG7, I5, and LI3) could grow at $5^{\circ}C$ to $20^{\circ}C$, pH 3.0 to 8.0 and NaCl (3.0%, 6.5%). Strains LCG3, LTG7, I5, and LI3 were identified as Lactobacillus plantarum, Pediococcus acidilactici, Lactobacillus paraplantarum, and Lactobacillus casei by sequencing 16S rDNA, respectively. All LAB inoculants significantly (p<0.05) increased lactic acid (LA) contents and ratios of lactic acid to acetic acid, and reduced pH and ammonia nitrogen/total nitrogen (AN/TN) compared with uninoculated silages at various temperatures ($10^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$). Compared to the commercial inoculant G, I5, and LI3 showed similar effects on improving the silage quality of Italian ryegrass at $10^{\circ}C$ and $15^{\circ}C$, indicated by similar pH, LA content and AN/TN. Conclusion: All inoculants could improve the silage fermentation quality at various temperatures ($10^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$). At the temperature of $10^{\circ}C$ and $15^{\circ}C$, strain I5 and LI3 had similar effects with the commercial inoculant G on improving the silage quality of Italian ryegrass.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.151-160
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• 1998

The Leuconostoc paramesenteroides dominated at refrigeration temperature range was isolated from kimchi, and improved its growth properties by mutation for competitive growth against Lactobacillus plantarum at lower pH. It was found that the minimal pH for the wild type Leuconostoc paramesenteroides Pw growth was pH 4.5 adjusted with HCI and pH 5.0 adjusted with organic-mixture (lactic acid:acetic acid=1:2), respectively. The mutant P-100 could grow in pH 4.0, 4.5, respectively, in MRS broth. Two strains Pw and P-100 were added into kimchi as starter and compared the quality characteristics of kimchi. The total acceptability of Pw and P-100 inoculated kimchi were evaluated better than that of control kimchi (no starter added) by sensory test and extended the optimal pH range of kimchi up to about 2.2, 2.5 times, respectively. In kimchi added P-100, the succinic acid was more abundant than others and the total number of Lactobacillus plantarum was down about 2.5 times in contrast to control kimchi.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.806-813
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• 1996

Five strains of psychrotrophic lactic acid bacteria which had been isolated from kimchi were inoculated as kimchi starters, and then their effects were investigated during fermentation at $8^{\circ}C$. The initial numbers of Gram negatives and coliforms in no-starter-inoculated kimchi were $4.0{\times}10^{6}CFU/ml\;and\;3.2{\times}10^4CFU/ml$ respectively, while these of lactic acid bacteria were only $1.6{\times}10^3CFU/ml$. Starter-inoculated kimchi showed sharp decreases in Gram negatives and coliforms from initial stage, but no-starter-inoculated kimchi showed slow increases in those bacteria in the early stage, and sharp decreases after 10 days. It took 10 days in no-starter-inoculated kimchi, $4{\sim}6$ days in Leuconostoc-inoculated kimchi and 2 days in Lactobacillus-inoculated kimchi for lactic acid bacteria to reach stationary phase of growth. No-starter-inoculated kimchi required 10 days to reach optimum ripened state, while all starter-inoculated kimchi samples required 4 days. The inoculations of all these starters did not cause over acidifications. Remarkable softening occurred in Leu. dextranicum-inoculated kimchi in 6 days, but did not in the rest. Except the Leu. paramesenteroides-inoculated kimchi, the qualities of Leuconostoc-inoculated kimchi were as good as those of no-starter-inoculated kimchi, but those of Lactobacillus-inoculated kimchi were not so good.