• Journal of Microbiology and Biotechnology
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• 제18권7호
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• pp.1266-1273
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• 2008

Lactic acid bacteria (LAB) with antimicrobial activity and high exopolysaccharide (EPS) production ability isolated from sourdough were studied for their fermentation characteristics as potential new starter cultures. The values of pH, titratable acidity, and viable cell counts were $4.06{\pm}0.009-4.50{\pm}0.015,\;0.787{\pm}0.020%-1.172{\pm}0.018%,\;and\;8.78{\pm}0.08-8.98{\pm}0.06$ log CFU/ml, respectively. In order to select probiotics with a high survival rate in the gut, isolates were tested to assess resistance against the artificial gastric acid and bile juice. Viable LAB counts were significantly (p<0.05) affected by the acidity. At pH 2.0, the total declines in the initial bacterial counts were 4.52$\pm$0.07 log for S. thermophilus St-Body-1, >7.98$\pm$0.03 log for E. flavescens DU-10, >7.95$\pm$0.05 log for E. faecium DU-12, and 3.15$\pm$0.06 log for L. amylovorus DU-21. Among the strains, L. amylovorus DU-21 was the only strain that had bile tolerance under simulated gastrointestinal conditions. In order to improve EPS production by L. amylovorus DU-21, the influence of carbon source was studied. When glucose was used as a carbon source, EPS production dramatically increased to 17.19$\pm$0.28 g/l (p<0.05). The maximum cell growth (10.012$\pm$>0.012 log CFU/ml) and EPS production (18.71$\pm$0.19 g/l) were achieved when 15 g/l of glucose was employed as the carbon source.

• 농업생명과학연구
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• 제46권5호
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• pp.83-90
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• 2012

A study was investigated the effects of the probiotic mixture (PM) contained Lactobacillus plantarum (L. plantarum) SY-99 $2.4{\times}10^9CFU/kg$ and Bacillus subtilis (B. subtilis) SJ-61 $2.2{\times}10^9CFU/kg$ on growth performance and fecal microflora counts of broiler chickens. Referred to the previous studies, a total of 160 one-day-old male broiler chicken (Ross 308) were randomly assigned to four experimental groups, which were a basal diet alone (control) and supplemented with PM 0.1 g/kg feed (T1), PM 0.2 g/kg feed (T2), and PM 0.4 g/kg feed (T3). After 28 days of administration, the average daily feed intake of T1 and T3 was significantly different compared to that of control (p<0.05). In addition, the feed conversion ratio of T2 and T3 was significantly improved compared to that of control (p<0.05). On the 28th day after administration, all treatment groups were significantly increased fecal lactic acid bacteria (LAB) counts and decreased fecal Enterobacteriaceae (ENT) counts compared to T1 (p<0.05). The results of this study indicated that the combination of L. plantarum and B. subtilis strains in the range of 0.2-0.4 g/kg feed could be used for the improvement of growth performance and fecal microflora in broiler chickens.

• 한국식품위생안전성학회지
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• 제12권4호
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• pp.346-353
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• 1997

This study was undertaken to find out distribution and contamination sources of hazardous microbes through microbial hazard analysis on the processing steps of surimi-based imitation crab (SBIC). As a results of ananlysis of 9 hazardous microbes for 16 raw materials and 8 processing steps, no Samonella spp. and Escherichia coli were detected in all samples. Level and distribution of hazardous microbes in mixed color were similar to those of surimi. Changes of aerobic plate counts (APC), psychrotropic bacteria, coliforms, Staphylococcus aureus and Vibrio parahaemolyticus showed similar trends at different processing steps. Thermotrophic bacteria and aerobic sporeformers were not detected until mixing step and feeding step, respectively and not reduced after cooking step. According to the comparison of APC at each step, it was suggested that surimi, workers and silent cutter at mixing step, and mixed color, workers and bundler at packaging step were the major contamination sources of bacteria.

• 미생물학회지
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• 제23권3호
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• pp.215-222
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• 1985

Distribution pattern and activity of heterotrophec bacteria were measured in the mudflat of Nakdong river estuary. In March and June, 1985, community sizes of amylolytic, lipolytic and proteolytic bacteria as well as total viable counts were measured. Vertical distribution of bacterial community size increased a few orders of magnitude from Narch to June. Heterotrophic activity was estimated in turnover time with $U-[^{14}C]-glucose$. Turnover time reduced considerably in June compared to that of March. To sxamine correlations for measured bacterial groups, turnover time and environmental factors, correlation coefficient matrix was obtained. These measured characteristics did not consistently correlate well with one another.

• Journal of Ginseng Research
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• 제20권3호
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• pp.299-306
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• 1996

This study was undertaken to examine the effects of fresh ginseng on the physicochemical and microbiological changes in dongchimi juice fermented under various conditions. The pH was somewhat lower in dongchimi juice added with 2.0% and 4.0% of fresh ginseng than that without ginseng, whereas the titratable acidity was higher in dongchimi juice with 2.0% and 4.0% of ginseng addition than the control. The addition of fresh ginseng to dongchimi preparation increased the numbers of total viable bacteria, lactic acid bacteria including Leuconostac mesenterotdes in dongchimi juice during fermentation. The changes in the counts of lactic acid bacteria were similar to those of total viable cells throughout the experiment except the initial stage of fermentation. However, the number of Leucosfastoc mesenternidgs decreased after the palatable stage. Key words : Panax ginseng C.A. Meyer, dongchlmi juice, pH, titratable acidity, microbiological changes.

• 한국식품저장유통학회지
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• 제12권3호
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• pp.263-266
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• 2005

전남 목포시의 각 가정에서 담근 물김치에서 총 24균주의 유산균을 분리하였다. 이들 분리 유산균 중 5균주가 인공 위액에서 내성을 나타내었다. 이들 유산균은 Lactobacillus plantarum으로 동정하였고, 특히 물김치로부터 동정된 유산균 MUL-2, MUL-4, MUL-18은 인공위액에서 3시간 배양 후에도 초기 생균수에 비해 변화가 거의 없어 가장 강한 내성을 나타내었다. 이들 분리 유산균은 병원성 미생물인 Listeria monocytogenes, Escherichia coli, Staphyrococcus aureus, Vibrio parahaemolyticus, Samonella typhimurium에 대해 뚜렷한 항미생물활성을 나타내었다.

• 대한의생명과학회지
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• 제10권4호
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• pp.403-406
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• 2004

Environmental endocrine disruptors (EDs) are toxic, hormone-like chemicals which can be found in our normal daily life. We have examined if EDs can inhibit the monocellular microorganisms such as lactic acid bacteria or if the growth of lactic acid bacteria could be resistant to the endocrine disruptors. We have used Lactobacillus paracasei subsp. paracasei (KCTC No. 3165) as an experimental strain and bisphenol A, benzophenone and phenylphenol for the comparison purpose. Experiments included the evaluation of turbidity, absorbance and actual cell counts. We found that No.3165 was somewhat resistant to EDs naturally, however, high concentration of EDs could inhibit the growth of No. 3165 completely. Different EDs showed different spectrum of inhibit. This study should contribute to the development of more resistant lactic acid bacteria to EDs and to the development of functional fermented beverage.

• 미생물학회지
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• 제28권3호
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• pp.229-235
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• 1990

평판배지상 세균 colony의 체외 세포 효소활성을 직접 측정할 수 있는 신속하고 정확한 방법에 대하여 기술하였다. 일반적으로 세균의 효소 특성을 살피기 위해서는 단백질, 전분, chitin, tween-80 등과 같은 고분자 물질을 첨가한 선택배지를 사용하고 있으나 그 방법상 여러 가지 문제점이 있다 그러므로 본 연구에서는 형광물질의 일종인 Methvlumbell liferyl(MUF) 기질이 일반적으보 사용되고 있는 천연 고분자 물질고 유사한가를 순수분리세균 균주를 이용하여 실험으로 검증하였다. MUF 기질 분해원리에 기초를 둔 기술한 새로운 방법은 순수 분리 균주는 물론 colony 계수에 사용되는 평판배지상에서도 세균의 체외세포 효소 특성을 정량적으로 측정 가능하게 한다. 본 새로운 방법을 이용하여 담수 생태계와 해양 퇴적토내 종속영양세균의 체외 효소 활성을 측정하여 고찰하였다.

• 한국식품영양학회지
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• 제12권1호
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• pp.77-84
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• 1999

The purpose of this study is to establish a rapid preparation method of Dongchimi-juice having favor-able flavor and high antibacterial activity against undesirable bacteria in Naengmyon-broth by using high antibacterial strains of lactic acid bacteria Lactobacillus homohiochii B21 and leuconostoc mesenteroid-es subsp. mesenteroides C16 as Dongchimi starter. When the two strains of lactic acid bacteria were used as starter mixed culture was better than single culture in acid production and antibacterial activity. When starter was not inoculated in Dongchimi fermentation the numbers of Gram negatives and colifor-ms were remarkably increased in early phase and antibacterial activity could scarcely be detected. But when starter was inoculated the numbers of Gram negatives and coliforms were sharply decreased from early phase and antibacterial ctivity was high. When Dongchimi was made with heat sterilized mat-erials and starter there were no Gram negatives and coliforms and antibacterial activity was high. The antibacterial activity of starter inoculated Dongchimi was maximum in 2 days of fermentation at 2$0^{\circ}C$ and was scarcely detected in six days. In consideration of coliform counts antibacterial activity and the flavor of Dongchimi the preparation method in which all materials were heat treated at 8$0^{\circ}C$ for 15 min-utes and inoculated with mixed starter of the two strains and fermented for 2 days at 2$0^{\circ}C$ was thoug-ht to be good.

• 한국수산과학회지
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• 제52권2호
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• pp.180-184
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• 2019

Aerobic bacteria, coliforms, Escherichia coli, and pathogenic bacteria were investigated in laver Porphyra sp. samples from various regions of Korea. The mean bacterial counts were $6.9{\pm}0.87log\;CFU/g$ (range 4.0 to 7.7) log CFU/g in dried laver, $2.83{\pm}4.36log\;CFU/g$ in roasted laver, and $4.93{\pm}1.43log\;CFU/g$ in seasoned laver. Coliforms were most abundant (mean count: $2.1{\pm}1.01log\;CFU/g$) in dried laver. No pathogenic bacteria, including Staphylococcus aureus, Salmonella spp. Vibrio parahaemolyticus, or Listeria monocytogenes, were detected in any of the samples. Aerobic microorganisms were the most diverse microorganisms in dried laver. Staphylococcus spp. were predominant, but S. aureus was not detected. Standardization of laver production is necessary to ensure a hygienic product because laver products are often ingested without heating or cooking, and the production process is simple.