• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.863-870
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• 2024

Meju, a fermented soybean brick, is a key component in soybean foods like doenjang and ganjang, harboring a variety of microorganisms, including bacteria and fungi. These microorganisms significantly contribute to the nutritional and sensory characteristics of doenjang and ganjang. Amplicon-based next-generation sequencing was applied to investigate how the microbial communities of meju fermented at low and high temperatures differ and how this variation affects the microbial communities of doenjang, a subsequently fermented soybean food. Our metagenomic data showed distinct patterns depending on the fermentation temperature. The microbial abundance in the bacterial community was increased under both temperatures during the fermentation of meju and doenjang. Weissella was the most abundant genus before the fermentation of meju, however, it was replaced by Bacillus at high temperature-fermented meju and lactic acid bacteria such as Weissella and Latilactobacillus at low temperature-fermented meju. Leuconostoc, Logiolactobacillus, and Tetragenococcus gradually took over the dominant role during the fermentation process of doenjang, replacing the previous dominant microorganisms. Mucor was dominant in the fungal community before and after meju fermentation, whereas Debaryomyces was dominant under both temperatures during doenjang fermentation. The dominant fungal genus of doenjang was not affected regardless of the fermentation temperature of meju. Strong correlations were shown for specific bacteria and fungi linked to specific fermentation temperatures. This study helps our understanding of meju fermentation process at different fermentation temperatures and highlights different bacteria and fungi associated with specific fermentation periods which may influence the nutritional and organoleptic properties of the final fermented soybean foods doenjang.

• Journal of Microbiology
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• v.45 no.6
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• pp.515-520
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• 2007

Vaginal lactic acid-producing bacteria of 80 pre-menopausal women were studied by isolation on Blood and DeMan-Rogosa-Sharpe agar, PCR with group-specific primers for Lactobacillus-denaturing gradient gel electrophoresis (DGGE), and PCR with specific primers for V3 region in 16S rRNA-temporal temperature gel electrophoresis (TTGE). Conventional isolation method on media detected only one lactobacillus (Lactobacillus brevis) while TTGE detected only Lactobacillus sp. DGGE detected seven Lactobacillus species; L. coleohominis, L. crispatus, L. iners, L. reuteri, L. rhamnosus, L. vaginalis, and Leuconostoc lactis. L. acidophilus and L. gasseri, which are prevalent in Western women, were not detected in Korean women. Furthermore, L. rhamnosus, Leuc. lactis, L. coleohominis, and Weissella cibaria, which were not previously reported in the vaginal microbiota of Korean women, were detected. The five most prevalent LABs in vaginal microbiota in Korean women were L. iners, Enterococcus faecalis, L. crispatus, Leuc. lactis, and W. cibaria.

• KOREAN POULTRY JOURNAL
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• v.40 no.12
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• pp.126-129
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• 2008

경부고속도로 천안휴게소에 서면 도로 너머로 화려한 원색의 기다란 건물이 보인다. 장난감을 만드는 회사인가 싶을 정도로 알록달록한 이곳은 외관의 느낌과 달리, 면역체계 증진을 위한 사료첨가제와 AI 예방제, 다약제내성병원체(MDRP)치료제를 개발 판매하고 있으며, 각종 친환경 유기농 제품군을 생산, 판매하고 있는 친환경 바이오 전문 기업 (주)리스나(대표 이종화, 이혁기, 정태호)의 본사이다. 리스나(Liisna)는 'Life is Nature'의 약자로 '삶은 곧 자연이다. 생명의 원천은 자연이다. 생명과 자연은 하나다.' 라는 의미를 포함하고 있다. 리스나의 전신인 구 오보바이오는 2005년 단국대학교 내 창업센터에서 시작해 2007년 지금의 자리로 이전하였다. 그리고 순환적 발전 모델을 추구하고자 2008년 8월 '(주)리스나'로 사명과 CI를 변경했다. 사명과 CI 변경을 통해 '바이셀라 코리엔시스(Weissella koreensis)'를 기반으로 한 바이오 사업 부문과 유기농 사업 부문이 순환적으로 결합되어 친환경 바이오 전문기업으로서의 시너지 효과를 꾀하고 있다. 아울러 '인류의 건강한 행복을 지향하는 기업' 이라는 비전을 이루기 위해 노력하고 있다.

• Ocean Science Journal
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• v.41 no.2
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• pp.113-119
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• 2006

Seventeen lactic acid bacterial strains (LAB) were isolated using MRS agar medium from Jeotgal, a Korean fermented food, purchased at the Jukdo market of Pohang. To identify the strains isolated, they were tested by examining their cell morphologies, gram-staining, catalase activity, arginine hydrolase activity, D-L lactate form and carbohydrate fermentation. According to the phenotypic characteristics, three strains were tentatively identified as Lactobacillus spp., ten were Enterococcus spp. (or Streptococcus spp., or Pediococcus spp.) and the rest were Leuconostoc spp. (or Weissella spp.). Five strains among 17 were chosen by preliminary bacteriocin activity test. Four bacterial strains which inhibited both indicator microorganisms were identified by 16S rRNA sequencing. The results are as follows; Leuconostoc mesenteroides (HK 4), Leuconostoc mesenteroides (HK 5), Leuconostoc mesenteroides(HK 11), Streptococcus salivarius(HK 8). In order to check LAB which are showing a high survival rate in gut, we investigated three strains inhibiting both indicator microorganisms in artificial gastric acid and bile juice -all except HK8. The three strains mentioned above grew in extreme low acid conditions.

• Korean Journal of Poultry Science
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• v.40 no.1
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• pp.57-65
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• 2013

This study was conducted to evaluate the effect of dietary Weissella koreensis (Wk), a prominent kimchi lactic acid bacteria supplementation on growth performance, nutrients utilization, gut microbiota and meat characteristics in broiler chicken. Both live and killed Wk was compared to know which could be more efficacious as a feed probiotics. Three Wk supplemented groups and no Wk supplemented group were designated according to supplementation levels and cell status. Those were; Control (no Wk), 0.1 % live Wk (LWk 0.1), 0.5% live Wk (LWk 0.5) and 0.5% killed Wk (KWk 0.5). Body weight gain and feed conversion efficiency were improved (P<0.05) by dietary LWk supplementation. KWk did not exert any benefit on growth performance. Crude protein utilizability of KWk supplemented diet was lower (P<0.05) than that of other diets. However, there were no differences among treatments in other nutrients utilization. Serum IgG concentration and relative weight of bursa of Fabricius was highest (P<0.05) in broiler chicken fed KWk 0.5 diet. Cecal anaerobic lactic acid bacteria count of LWk groups were higher (P<0.05) than those of control and KWk 0.5 groups. Dietary Wk supplementation failed to lower the count of cecal and fecal E. coli. There was no effect of dietary Wk on TBARS values and fatty acids profile of broiler leg meat. However, the dietary supplementation of Wk exerted characteristic difference on electronic nose flavor of broiler meat. This study showed that dietary supplementation of LWk was able to improve body weight gain, feed conversion efficiency and cecal lactic acid bacterial count in broiler chicken. Further, the result of this study implemented that a live kimchi lactic acid bacteria, LWk, but not killed Wk, could be used as a probiotic feed supplement for broiler.

• Journal of Life Science
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• v.31 no.12
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• pp.1079-1087
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• 2021

To analyze gut microbiota of livestock in Korea and compare taxonomic differences, we conducted 16S rRNA metagenomic analysis through next-generation sequencing. Fecal samples from broiler chickens, pigs, and cattle were collected from domestic feedlots randomly. α-diversity results showed that significant differences in estimated species richness estimates (Chao1 and ACE, Abundance-based coverage estimators) and species richness index (OUTs, Operational taxonomic units) were identified among the three groups. However, NPShannon, Shannon, and Simpson indices revealed that abundance and evenness of the species were statistically significant only for poultry (broiler chickens) and mammals (pigs and cattle). Firmicutes was the most predominant phylum in the three groups of fecal samples. Linear discriminant (LDA) effect size (LEfSe) analysis was conducted to reveal the ranking order of abundant taxa in each of the fecal samples. A size-effect over 2.0 on the logarithmic LDA score was used as a discriminative functional biomarker. As shown by the fecal analysis at the genus level, broiler chickens were characterized by the presence of Weissella and Lactobacillus, as well as pigs were characterized by the presence of provetella and cattele were characterized by the presence of Acinetobacter. A permutational multivariate analysis of variance (PERMANOVA) showed that differences of microbial clusters among three groups were significant at the confidence level. (p=0.001). This study provides basic data that could be useful in future research on microorganisms associated with performance growth, as well as in studies on the livestock gut microbiome to increase productivity in the domestic livestock industry.

• Journal of Life Science
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• v.21 no.10
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• pp.1428-1433
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• 2011

In this study, we isolated and characterized plant-associated lactic acid bacteria which are able to produce angiotensin-converting enzyme (ACE) inhibitory and antioxidative activities. Five lactic acid bacteria were isolated from plants (grape and leek), a plant-associated fermentative product (Kimchi) and Korean traditional alcohol (Dongdongju). Strains K-1 and K-21 from Kimchi, strain L-5 from leek, strain G-3 from grape, and strain D-3 from Dongdongju were identified as Pediococcus pentosaceus, Lactobacillus plantarum, Weissella cibaria, L. plantarum, and L. brevis, respectively, by 16S rRNA gene analysis. ACE inhibitory activities of isolated strains ranged from 44.3 to 71.9% in the MRS broth. G-3, L-5 and K-1 strains especially showed high ACE inhibitory activities (59.8-98.69%) in the MRS broth containing skim milk. DPPH radical scavenging activities of the strains were in the range of 42.5-82.7%. All strains showed varying levels of resistance in artificial gastric fluid (pH 2.5), retaining viability ranging from 42.2 to 88.1% after 3 hr of incubation. All strains showed high resistance to 0.3% oxgall after 24 hr of incubation; survival rates were in the range of 55.4-112.8%. Isolated strains were found to be antagonistic to some pathogens including Pseudomonas aeruginosa.

• Journal of Life Science
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• v.26 no.4
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• pp.496-502
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• 2016

This review describes the diversity of Korean fermented foods and their significance as potential sources of probiotic bacteria. Fermented foods consumed in Korea are categorized according to their base material. Fermented foods such as kimchi, meju, doenjang, kangjang, jeotgal, and makgeolli are reported to have significant medicinal properties. These fermented products, which are consumed regularly by local people, are rich sources of beneficial microbes represented by several genera, including Weissella spp., Lactobacillus spp., Leuconostoc spp., Mucor, Penicillium, Scopulariopsis, Aspergillus, Rhodotorula, Candida, Saccharomyces, and Bacillus, as well as lactic acid bacteria. Fermented foods are now taken beyond the boundaries of their use as mere side dishes and are used significantly as a functional as well as medicinal foods. Fermented foods are a rich source of potential natural substances with antioxidant, anticancer, anticholesteric, antiobesitic, and antiaging properties, so that traditional fermented foods used as food supplements can impart health benefits. Publication of scientific studies on the dietary benefits of various fermented foods and growing consciousness about the potential health benefits of traditional fermented food are reflected in the scores of reports currently available in this field. Food microbiologists now have abundant opportunities to explore Korean traditional fermented foods for the isolation of new bacterial strains and to evaluate the potential applications of these strains through microbiological research.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.701-708
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• 2017

This study was conducted to evaluate the hyaluronidase (HAase) inhibition activity of Asparagus cochinchinesis (AC) extracts following fermentation by Weissella cibaria through response surface methodology. To optimize the HAase inhibition activity, a central composite design was introduced based on four variables: the concentration of AC extract ($X_1$: 1-5%), amount of starter culture ($X_2$: 1-5%), pH ($X_3$: 4-8), and fermentation time ($X_4$: 0-10 days). The experimental data were fitted to quadratic regression equations, the accuracy of the equations was analyzed by ANOVA, and the regression coefficients for the surface quadratic model of HAase inhibition activity in the fermented AC extract were estimated by the F test and the corresponding p values. The HAase inhibition activity indicated that fermentation time was most significant among the parameters within the conditions tested. To validate the model, two different conditions among those generated by the Design Expert program were selected. Under both conditions, predicted and experimental data agreed well. Moreover, the content of protodioscin (a well-known compound related to anti-inflammation activity) was elevated after fermentation of the AC extract at the optimized fermentation condition.

• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.529-537
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• 2020

This study was carried out to confirm changes in the microbial community and physicochemical characteristics of Korean traditional Makgeolli during fermentation by yeast as a fermentation starter. We demonstrate that the microbial community during fermentation affects the quality of Makgeolli. At the species level, Pediococcus pentosaceus, Weissella confusa, Pantoea vagans, and Lactobacillus graminis were dominant on fermentation mix, after 1-2 days, in the control group without yeast treatment. Acid production in the control group was higher than that in the yeast-treated group. P. pentosaceus was dominant throughout the fermentation process, and the proportion of P. vagans remarkably decreased following yeast addition. Considering quality characteristics, the alcohol content rapidly increased after yeast addition, and the lactic acid content was lower in the yeast-treated group than in the control. These results suggest that the rapid increase in alcohol at the start of fermentation inhibits the growth of lactic acid-producing bacteria. The addition of yeast may contribute to the reduction in the high amount of lactic acid, which can be one of the causes of changes in Makgeolli quality.