• 한국미생물·생명공학회지
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• 제22권6호
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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.

• 한국식품영양과학회지
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• 제27권2호
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• pp.244-251
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• 1998

To understand the effect of supplement of water extract of pine needle(WEPN) on shelf-life enhancement of the kimchi, activities of four enzymes and number of lactic acid bacteria, during fermentation of the kimchi, were assayed. Enzyme activities of kimchi fermented for 7 days with supplement by 2% water extract of pine needle showed amylase of 86.4%, protease of 85.8%, polygalacturonase of 61.5% and $\beta$-galactosidase of 58.8% against the control kimchi. WEPN showed weak inhibitory effect when it was applied to the isolated enzymes in vitro then those menifested by the kimchi in vivo. Number of total bacterial cell of WEPN supplemented kimchi increased by 10 folds than control between 7 to 14 days of fermentation. On contrast, number of lactic acid bacteria decreased maximaly to 21% of control by fermentation. The clear zone formed on paper disk by WEPN against L. plantarum was larger than that of Leu. mesenteroides.

• Asian-Australasian Journal of Animal Sciences
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• 제10권6호
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• pp.593-598
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• 1997

The changes of tissue structure in timothy and alfalfa during ensiling process with silage additives; lactic acid bacteria, cellulase and formic acid, were observed with a video microscope. Stem samples were obtained from the second internode, and cut to divide into 2 pieces. One piece was for observation of ensiled material and the other was for silage. The latter piece was put into a nylon cloth bag, and ensiled with grass for 50 days in a small experimental silo Lignification of the plant tissues was checked by acid phloroglucinol. Natural silage fermentation resulted in some degradation of less lignified parenchyma in both plant species. However, lignified sclerenchyma and vascular bundles remained intact. The cellulase enhanced the degradation of parenchyma tissue, while the formic acid suppressed the degradation. The effect of lactobacillus was small. The percentage of remained cross sectional area of stem and the loss of NDF and ADF by silage fermentation confirmed the observation. High negative correlations were obtained between the remained area and loss of fibrous components during silage fermentation in both plants, and between the loss of fibrous components and in vitro dry matter digestibility in timothy but not in alfalfa.

• 한국조리학회지
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• 제14권3호
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• pp.136-142
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• 2008

This study was conducted to investigate the correlation of the physicochemical quality index(pH, acidity, reducing sugar content and lactic acid bacterial count) and sensory index(sourness) of Kakdugi during the fermentation at 5$^{\circ}C$, 10$^{\circ}C$ and 20$^{\circ}C$ respectively. Also, the relations between physicochemical quality index and overall acceptability were carried out. The pH range, based on the middle sour intensity point of 4.5, was 5.75 at 5$^{\circ}C$ fermentation, whereas that was 4.2 at 10$^{\circ}C$ and 20$^{\circ}C$ fermentation. The pH showing the highest overall acceptability decreased along with increased fermentation temperature. The reduced sugar content decreased rapidly up to 0.9% acidity, but after that, decreased slowly from more than 0.9% acidity at all fermentation temperatures. With increased fermentation temperature, the reduced sugar content showing the highest overall acceptability also showed the decreasing tendency. Change patterns of lactic acid bacterial count and sourness didn't coincided at 5$^{\circ}C$ fermentation, whereas those did at 10$^{\circ}C$ and 20$^{\circ}C$ fermentation. The indexes showing high significant correlations with sourness of Kakdugi fermented at 5$^{\circ}C$ were not pH and lactic acid bacterial count but acidity and reducing sugar content(p<0.05). The sourness of Kakdugi fermented at 10$^{\circ}C$ and 20$^{\circ}C$ showed high significant correlations with all of the physicochemical index(p<0.05).

• Journal of Microbiology and Biotechnology
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• 제19권6호
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• pp.616-621
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• 2009

To evaluate the effects of lactic acid bacteria (LAB) in inflammatory bowel diseases (IBD), we measured the inhibitory effect of several LAB isolated from intestinal microflora and commercial probiotics against the glycosaminoglycan (GAG) degradation by intestinal bacteria. Bifidobacterium longum HY8004 and Lactobacillus plantarum AK8-4 exhibited the most potent inhibition. These LAB inhibited colon shortening and myeloperoxidase production in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced experimental colitic mice. These LAB also blocked the expression of the proinflammatory cytokines, IL-$1{\beta}$ and TNF-$\alpha$, as well as of COX-2, in the colon. LAB also blocked activation of the transcription factor, NF-${\kappa}B$, and expression of TLR-4 induced by TNBS. In addition, LAB reduced the TNBS-induced bacterial degradation activities of chondroitin sulfate and hyaluronic acid. These findings suggest that GAG degradation-inhibitory LAB may improve colitis by inhibiting inflammatory cytokine expression via TLR-4-linked NF-${\kappa}B$ activation and by inhibiting intestinal bacterial GAG degradation.

• Asian-Australasian Journal of Animal Sciences
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• 제16권5호
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• pp.726-731
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• 2003

The aim of this research was to identify candidate probiotic lactic bacteria among indigenous dadih lactic isolates. Dadih is an Indonesian traditional fermented milk of West Sumatra which is fermented naturally. Viability of the strain is critical in determining the capacity of lactic bacteria to induce immune stimulation as well as to colonize in the intestinal tract. Therefore, LAB are proposed to exert health promoting or probiotic effects in human, such as inhibition of pathogenic microflora, antimutagenic, and the reduction of cholesterol levels. This manuscript reports in vitro probiotic properties of indigenous dadih lactic bacteria, especially some important colonization factors in GI tract, such as lysozyme, acid and bile tolerance. Bile Salt Hydrolase (BSH) activity, spectrum of bacteriocin, and antimutagenic activity of bacterial cells were also assessed. Twenty dadih lactic isolates were screened further for their tolerance to low pH, at pH 2 and 3 as well as their bile tolerance. There were ten isolates classified as acid and bile acid tolerant, and further screened for lysozyme tolerance, BSH activity. The spectrum of bacteriocin activity of isolates was assayed using cell-free neutralized supernatants by agar spot test against variety of pathogens. Lc. lactis subsp. lactis IS-10285, IS-7386, IS-16183, IS-11857 and IS-29862, L. brevis IS-27560, IS-26958 and IS-23427, Leu.mesen.mesenteroides IS-27526, and L. casei IS-7257 each has good survival rate at low pH values and in the presence of lysozyme, and short lag time in the presence of 0.3 % oxgall. Lc. lactis subsp. lactis IS-11857 and IS-29862 each has high BHS activity, Lc. lactis subsp. lactis IS-10285 and IS-16183 each had a positive spectrum of bacteriocin activity against E. coli 3301 and Lysteria monocytogenes ATCC 19112, while L. brevis IS-26958 has high BHS activity as well as positive spectrum of bacteriocin against E. coli 3301, Lysteria monocytogenes ATCC 19112, and S. aureus IFO 3060. All of the ten dadih lactic strains performed in vitro acid and bile tolerance, indicating a possibility to reach the intestine alive, and display probiotic activities.

• Asian-Australasian Journal of Animal Sciences
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• 제23권7호
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• pp.901-906
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• 2010

The improvement of the fermentation quality of rice straw silage by application of lactic acid bacteria (LAB) and glucose was investigated in this study. Sixteen rice varieties were harvested at the maturity stage and the rice straw was ensiled with LAB inoculant ($1{\times}10^5$ cfu/g of fresh weight) and glucose (2% of fresh weight). Inoculation with LAB improved the fermentation as reflected in reductions in pH, acetic acid (by 3.7 to 78.3%), butyric acid (by -6.0 to 100.0%) and ammonia nitrogen (by 1.0 to 71.7%) concentrations, and increases in lactic acid (by 43.9 to 282.9%) and crude protein concentrations compared with the control. Application of LAB plus glucose was more effective in improving fermentation quality than LAB alone. The variety of rice straw which contained relatively high levels of water soluble carbohydrates (WSC) tended to obtain better fermentation quality. The results suggested that LAB application and selection of rice varieties whose straw contained high levels of WSC were effective in improvement of the fermentation quality of rice straw silage.

• Journal of Microbiology and Biotechnology
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• 제22권11호
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• pp.1523-1531
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• 2012

The metabolite profile of meju during fermentation was analyzed using mass spectrometry techniques, including GC-MS and LC-MS, and the bacterial diversity was characterized. The relative proportions of bacterial strains indicated that lactic acid bacteria, such as Enterococcus faecium and Leuconostoc lactis, were the dominant species. In partial least-squares discriminate analysis (PLS-DA), the componential changes, which depended on fermentation, proceeded gradually in both the GC-MS and LC-MS data sets. During fermentation, lactic acid, amino acids, monosaccharides, sugar alcohols, and isoflavonoid aglycones (daidzein and genistein) increased, whereas citric acid, glucosides, and disaccharides decreased. MS-based metabolite profiling and bacterial diversity characterization of meju demonstrated the changes in metabolites according to the fermentation period and provided a better understanding of the correlation between metabolites and bacterial diversity.

• Journal of Microbiology and Biotechnology
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• 제26권6호
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• pp.1148-1161
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• 2016

Lactobacilli are universally recognized as probiotics that are widely used in the adjuvant treatment of inflammatory diseases, such as vaginitis and enteritis. With the overuse of antibiotics in recent years, the lactobacilli in the human body are killed, which could disrupt the microecological balance in the human body and affect health adversely. In this work, cephalosporin-resistant Lactobacillus casei RL20 was obtained successfully from the feces of healthy volunteers, which possessed a stable genetic set. However, the shortage of lactic acid (72.0 g/l at 48 h) by fermentation did not meet the requirement for its use in medicine. To increase the production of lactic acid, the functional genes pfk and glk were introduced into the wild strain. A yield of 144.2 g/l lactic acid was obtained in the transgenic L. casei RL20-2 after fermentation for 48 h in 1 L of basic fermentation medium with an initial glucose concentration of 100 g/l and increasing antibacterial activity. These data suggested that L. casei RL20-2 that exhibited a high yield of lactic acid may be a potential probiotic to inhibit the spread of bacterial infectious diseases and may be used for vaginitis therapy.

• Journal of Microbiology and Biotechnology
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• 제28권6호
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• pp.946-956
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• 2018

The gut microbiota of aquatic animals plays a crucial role in host health through nutrient acquisition and outcompetition of pathogens. In this study, on the basis of the high-throughput sequencing of 16S rRNA gene amplicons, we examined the bacterial communities in the gut of freshwater shrimp (Macrobrachium nipponense) and in their living environments (sediment and pond water) and analyzed the effects of abiotic and biotic factors on the shrimp gut bacterial communities. High bacterial heterogeneity was observed in the freshwater shrimp gut samples, and the result indicated that both the surrounding bacterial community and water quality factors (particularly dissolved oxygen and temperature) could affect the shrimp gut bacterial community. Despite the observed heterogeneity, 57 genera, constituting 38-99% of the total genera in each of the 40 shrimp gut samples, were identified as the main bacterial population in the gut of M. nipponense. In addition, a high diversity and abundance of lactic acid bacteria (26 genera), which could play significant roles in the digestion process in shrimp, were observed in the shrimp gut samples. Overall, this study provides insights into the gut bacterial communities of freshwater shrimp and basic information for shrimp farming regarding the application of probiotics and disease prevention.