• 한국수산과학회지
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• 제44권6호
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• pp.605-611
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• 2011

This study examined the suitability of characteristics of potential strains of probiotic bacteria. Among 25 lactic acid bacteria isolated from Korean traditional fermented food, the Hard Clam Meretrix meretrix Shikhae, the SH-10 strain, which exhibited superior resistance to low pH and bile salts, was selected as a potential probiotic bacteria. By examining carbohydrate utilization, morphological properties, and the 16S rRNA gene sequence, the SH-10 strain was identified as Pediococcus pentosaceus (hereafter, P. pentosaceus SH-10). P. pentosaceus SH-10 was resistant to amikacin, cefotetan, ciprofloxacin, gentamicin, kanamycin, nalidixic acid, streptomycin, and vancomycin. Tests of antimicrobial activities against pathogens such as Bacillus cereus, Listeria monocytogenes, Salmonella choleraesuis, and Staphylococcus aureus, indicated that P. pentosaceus SH-10 inhibited the growth of pathogenic bacteria. These results suggest that P. pentosaceus SH-10 can be developed as a probiotic bacteria.

• 한국식품영양과학회지
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• 제28권4호
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• pp.830-836
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• 1999

돼지장에 존재하는 많은 균총들로부터 생균제를 분리하기 위하여 생균제로서 필수 조건인 내산성, 내담즙산, 유해균 억제능력들을 조사하였는데 그 결과 다른 균들에 비해 생균제로서 작용 능력이 뛰어난 한 균주인 PA10을 얻을 수 있었다. 생균제로서 중요한 기능인 설사 유발 대장균과 Salmonella를 억제하기 위하여 돼지의 장으로부터 내산, 내담즙의 특성을 가진 미생물틀을 분리 검색하였다. 이들 중, 위산과 담즙에 잘 견디며, 대장균 및 Salmonella에 대한 억제 능력이 뛰어난 한 미생물을 분리하였는데 Lactobacillus salivarious로서 동정되었다. 이미 생물은 pH 3의 위산과 0.3% 담즙산에서 각각 2시간, 24시간 동안 약 50~70%의 생존률을 나타냈으며, 대장균 또는 Salmonella를 MRS배지에서 혼합 배양시 24시간안에 이들 유해균을 완전히 제거할 수 있었다. 이 실험에서 L salivarius로 명명된 이 균은 돼지장에 서식하는 수 많은 미생물중 내산, 내담즙산, 유해균 억제능을 동시에 만족 시킬 수 있는 특성을 가지는 균주임을 알 수 있었다. 앞으로 균주 보존 조건을 확립하고, 동물 실험에서도 유사한 결과를 얻을 수 있다면 이 분리균은 생균제로서 유용하게 이용될 수 있을 것으로 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권10호
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• pp.1490-1499
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• 2016

In this study, 69 lactobacilli isolated from Tibetan Qula, a raw yak milk cheese, were screened for their potential use as probiotics. The isolates were tested in terms of: Their ability to survive at pH 2.0, pH 3.0, and in the presence of 0.3% bile salts; tolerance of simulated gastric and intestinal juices; antimicrobial activity; sensitivity against 11 specific antibiotics; and their cell surface hydrophobicity. The results show that out of the 69 strains, 29 strains (42%) had survival rates above 90% after 2 h of incubation at pH values of 2.0 or 3.0. Of these 29 strains, 21 strains showed a tolerance for 0.3% bile salt. Incubation of these 21 isolates in simulated gastrointestinal fluid for 3 h revealed survival rates above 90%; the survival rate for 20 of these isolates remained above 90% after 4 h of incubation in simulated intestinal fluid. The viable counts of bacteria after incubation in simulated gastric fluid for 3 h and simulated intestinal fluid for 4 h were both significantly different compared with the counts at 0 h (p<0.001). Further screening performed on the above 20 isolates indicated that all 20 lactobacilli strains exhibited inhibitory activity against Micrococcus luteus ATCC 4698, Bacillus subtilis ATCC 6633, Listeria monocytogenes ATCC 19115, and Salmonella enterica ATCC 43971. Moreover, all of the strains were resistant to vancomycin and streptomycin. Of the 20 strains, three were resistant to all 11 elected antibiotics (ciprofloxacin, erythromycin, tetracycline, penicillin G, ampicillin, streptomycin, polymyxin B, vancomycin, chloramphenicol, rifampicin, and gentamicin) in this study, and five were sensitive to more than half of the antibiotics. Additionally, the cell surface hydrophobicity of seven of the 20 lactobacilli strains was above 70%, including strains Lactobacillus casei 1,133 (92%), Lactobacillus plantarum 1086-1 (82%), Lactobacillus casei 1089 (81%), Lactobacillus casei 1138 (79%), Lactobacillus buchneri 1059 (78%), Lactobacillus plantarum 1141 (75%), and Lactobacillus plantarum 1197 (71%). Together, these results suggest that these seven strains are good probiotic candidates, and that tolerance against bile acid, simulated gastric and intestinal juices, antimicrobial activity, antibiotic resistance, and cell surface hydrophobicity could be adopted for preliminary screening of potentially probiotic lactobacilli.

• Journal of Microbiology and Biotechnology
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• 제16권8호
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• pp.1201-1209
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• 2006

The purpose of this study was to isolate probiotic lactic acid bacteria (LAB) that produce bile salt hydrolase (BSH), and to evaluate its effects on serum cholesterol level. One-hundred-twenty bacterial colonies were initially isolated from human feces, and five strains were selected after screening based on their resistance to acids, tolerance against bile salts, and inhibitory activity on Escherichia coli. The Lactobacillus plantarum strain with the highest level of BSH activity was identified using 16S rRNA sequences, and was named L. plantarum CK 102. L. plantarum CK 102 at a level of 1.36$\times$10$^8$cfu/ml survived in pH 2 buffer for 6 h and exhibited excellent tolerance for bile salt. Coculturing the strain with E. coli in MRS broth resulted in strong inhibition against growth of E. coli at 18 h. Furthermore, the potential effect of CK 102 on serum cholesterol level was evaluated in rats. Thirty-two rats [Sprague-Dawley (SD) male, 129$\pm$l g, 5 weeks old] were divided into four groups of eight each. For six weeks, Group 1 was fed a normal diet (negative control); Group 2 was fed a cholesterol-enriched diet (positive control); Group 3 was fed a cholesterol-enriched diet plus L. plantarum CK 102 at 1.0$\times$10$^7$cfu/ml; and Group 4 was fed a cholesterol-enriched diet plus L. plantarum CK 102 at 5.0$\times$10$^7$cfu/ml. Blood samples were collected, serum lipids were analyzed, and weights of the organs were measured. Total blood cholesterol level, triglyceride, LDL-cholesterol, and free-cholesterol values were lower in rats that were fed 1. plantarum CK 102 than in those not fed L. plantarum CK 102. This cholesterol lowering effect implies that L. plantarum CK 102 could be utilized as an additive for health-assistance foods. In conclusion, these results suggest that the 1. plantarum CK 102 isolated could be used commercially as a probiotic.

• 동의생리병리학회지
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• 제27권1호
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• pp.107-111
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• 2013

To investigate the possible usage as probiotics, we isolated and identified one strain of bacillus from Korean traditional food, Jeotgal. The isolate was identified as Bacillus megaterium KS12 by examining its biochemical properties and 16S rRNA sequence analysis (99% similarity). B. megaterium KS12 exhibited high viability in artificial gastric juice for 3 h and in artificial bile salts for 24 h, about 14.4 and 14%, respectively. The herbal digestive medicine containing the isolate showed high starch hydrolytic activity and proteolytic activities (about 6-fold) compared to traditional herbal digestive medicine. The viable cells in the herbal digestive medicine containing the isolate were higher than those of traditional herbal digestive medicine.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.161-168
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• 2010

In this study, the metabolic activities of five strains of Pediococcus spp., in terms of the quantities they produced of lactic acid, hydrogen peroxide, exopolysaccharides, and proteolytic activity, were determined. Lactic acid levels produced by these strains were found to be in the range of 2.5-5.6 mg/ml. All strains produced hydrogen peroxide. The P. pentosaceus Z13P strain produced the maximum amount (0.25 mg/ml) of proteolytic activity. Exopolysaccharide (EPS) production by the Pediococcus strains during growth in MRS (de Man, Rogosa, and Sharpe) medium was in the range 25-64 mg/l. The susceptibility of 10 different antibiotics against these strains was also tested. All strains were found to be resistant to amoxicillin, gentamicin, and vancomycin. Antimicrobial effects of the Pediococcus spp. on pathogens were also determined by an agar diffusion method. All of the strains were able to inhibit L. monocytogenes. The tolerance of the strains to low pH, their resistance to bile salts of strains, and their abilities to autoaggregate and coaggregate with L. monocytogenes were also evaluated.

• Food Science and Biotechnology
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• 제15권6호
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• pp.866-870
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• 2006

The maintenance of physiological activity during dilution is very critical for the accurate enumeration of Vibrio spp. in marine samples. We investigated the effect of various diluents on the recovery of Vibrio parahaemolyticus using the direct plate counting and most probable number (MPN) methods. The effects of NaCl (0.85 and 3%) and pH (from 6.6 to 7.4) in diluents based on distilled water or phosphate buffered saline (PBS) were evaluated with three V. parahaemolyticus strains. PBS-3% NaCl (pH 6.6), as opposed to PBS, was the most effective diluent at maintaining viable cell numbers up to 2 log CFU/g during dilution for direct plate counting using on thiosulfate citrate bile salts sucrose (TCBS) selective agar, as well as minimizing the difference in cell numbers between TCBS and non-selective nutrient agar. It also increased counts of V parahaemolyticus inoculated into oysters relative to PBS (p<0.01), suggesting that PBS-3% NaCl (PH 6.6) can reduce the problem of underestimating V. parhaemolyticus counts using PBS alone.

• 한국수산과학회지
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• 제49권3호
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• pp.359-366
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• 2016

The health of Alaska pollock Theragra chalcogramma seedlings was monitored during February and April 2015. After microscopic examination for parasites, 20 samples sets were made by pooling 50 individuals for each sample set. Then, they were homogenized and examined for viral and bacterial pathogens. No parasites or viruses were detected using either microscopy or PCR. Colonies suspected of belonging to the genus Vibrio were isolated from Tryptic Soya Agar and Thiosulfate Citrate Bile Salts Sucrose Agar plate incubations, and identified as Vibrio anguillarum based on biochemical and physiological examinations and PCR amplification of the 16S rDNA, recA, and pyrH genes. Although there was no mortality during the sampling period, 65.0% (13/20) of the pooled samples were PCR-positive for V. anguillarum. To prevent possible outbreaks, the pathogenic potential of V. anguillarum should be investigated in the future.

• KSBB Journal
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• 제15권1호
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• pp.1-8
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• 2000

The diffusion effect of simulated gastric juices into the various alginate vessel containing each biopolymer such as 0.3% soluble starch, whey, corn starch, agar, locust bean gum, guar gum, gum arabic, pectin, gelatin and 0.15% xanthan gum was tested by measuring the change of pH in the vessel. The degree of viability of bifidobacteria entrapped in each bead containing biopolymers was corresponded with the degree of diffusion inhibition of hydrogen into the each vessel. Therefore, The determination of diffusion inhibition of simulated gastric juices into the various vessel by measuring the change of pH in the vessel may be effectively used as the simple method to select the optimal entrapment lattice for the improvement of bifidobacteria viability. Bifidobacteria entrapped in alginate bead containing 0.15% xanthan gum whose lattice showed the lowest hydrogen diffusion were more significantly tolerant against bile salts and hydrogen peroxide than untrapped bifidobacteria. It was also observed that the viability of bifidobacteria entrapped in bead was nto nearly changed in milk adjusted pH 4.5 with organic adids at $4^{\circ}C$ for 10 days. Therefore, use of alginate containing 0.15% xanthan gum as a cell matrix for entrapping bifidobacteria was expected to improve the viability of bididobacteria in fermented milk products and develop the high value-added products.

• Journal of Dairy Science and Biotechnology
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• 제14권2호
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• pp.195-206
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• 1996

Cholesterol assimilated by Lactobacillus acidophilus ATCC 43121 was not metabolically degraded in that most of it was recovered with the cells. Cells grown in the presence of cholesterol micelles and bile salts were more resistant to Iysis by sonication than those grown in their absence, suggesting a possible alteration of cellular membranes. Cholesterol assimilation occurred during growth at pH 6.0, the amount of which was more than that by cells grown without pH control. Cholesterol assimilated by cells was recovered in the membrane fractions of cells both grown at pH 6.0 and without pH control. The effect of unsaturated fatty acids on cholesterol assimilation was not clear, since there was no significant (P> 0.05) difference in the amount taken up from micelles prepared using L-${\alpha}$-phosphatidylcholine, dioleoyl or L-${\alpha}$-phosphatidylcholine, distearoyl. Without Tween 80, little, if any, cell growth or cholesterol uptake was observed. In the presence of 0.05% Tween 80, cholesterol uptake increased dramatically as did growth. However, as the amount of Tween 80 increased beyond 0.05%, cholesterol uptake decreased while the amount of growth remained the same.