• Journal of Microbiology and Biotechnology
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• 제5권5호
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• pp.257-263
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• 1995

As a first step for developing Lactobacillus strains capable of fermenting starch directly, the $\alpha$-amylase gene (amyL) from Bacillus licheniformis (Kim et al., 1988. Kor. J. Appl. Microbiol. Bioeng. 16: 369-373) was introduced into Lactobacillus casei strains and the level of $\alpha$-amylase expression in transformants was examined. 3 kb EcoRI fragments encompassing amyL were subcloned into the suitable lactococcal cloning vectors (pSA3, pMG36e, and p1L2530) and then recombinant plasmids were introduced into E. coli and L. casei strains by electroporation. Only one recombinant plasmid, $pIL2530\alpha$ was able to transform few L. casei strains tested at low efficiencies. The transformation efficiencies with the plasmid into L. casei YIT 9018 and L. casei A Tee 4646 were less than $10^2/\mu$ g pIL2530\alpha$. The level of amylase activities in L. casei was five to ten-fold lower than that in E. coli cells. $p1L2530\alpha$ was stably maintained in Lactobacillus strains in the presence of Em (5 $\mu $g/ml) but without antibiotic selection, it was unstable so more than 95$%$ of cells lost plasmids after a week of daily subculturing.

• Asian-Australasian Journal of Animal Sciences
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• 제19권1호
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• pp.131-136
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• 2006

During lactic acid bacteria (LAB) transit through the gastrointestinal tract, ingested microorganisms were exposed to successive stress factors, including low pH in the human stomach and in bile acid. These stress factors can be used as criteria for the selection of a viable probiotic strain. Four such strains (Lactobacillus helveticus SGU 0011, Lactobacillus pentosus SGU 0010, Streptococcus thermophilus SGU 0021 and Lactobacillus casei SGU 0020) were isolated from raw milk. When the identified LAB were exposed to synthetic gastric juice, whereas L. casei SGU 0020 and S. thermophilus SGU 0021 exhibited a 0% survival rate, L. helveticus SGU 0011 and L. pentosus SGU 0010 exhibited 60% and 95% survival rates. L. casei SGU 0020 and S. thermophilus SGU 0021 could not be examined with regard to their tolerances to artificial bile juice, as they uniformly died upon exposure. However, L. helveticus SGU 0011 and L. pentosus SGU 0010 individually survived at rates of 39% and 93%. Also, all four of these strains were confirmed to be tolerant of ten different antibiotics.

• 대한수의학회지
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• 제40권4호
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• pp.701-706
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• 2000

This study was carried out to select the lactic acid bacteria(Lactobacillus, Streptococcus and Bifidobacterium) and yeast for probiotic use in pigs. Acid-tolerant 536 strains were isolated from the feces of 30 pigs. To select useful strains, the first screened strains were treated with strong acid solution(pH 2.5 to 3.0) for 3 hours and subsequentely treated with the anaerobic diluent solution containing 0.15% Oxgall for 3 hours. Among these strains, 151 strains showed strong tolerance to both acid and bile. Lactobacillus and Streptococcus tolerant to the acid and bile were treated with heat at $80^{\circ}C$ for 15 min, and at $70^{\circ}C$ for 5 min in Bifidobacterium and yeast. As a result of heat treatment, 38 strains were obtained as heat-tolerant strains. All of heat-tolerant strains were tested for antibiotic resistance against virginiamycin, sulfathiazole, aureomycin, neomycin, linsmycin, tiamulin and ASP250 which were used as feed additives for growth promotion in pigs. Finally, one strain each from Lactobacillus, Streptococcus, Bifidobacterium and yeast that showed resistance to acid, bile, heat and antibiotics was selected for probiotic use in pigs.

• 한국식품저장유통학회지
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• 제10권3호
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• pp.406-410
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• 2003

생균제로서 가능성 있는 유산균의 선별을 위해 발효식품인 동치미로부터 분리된 균주들의 내산성, 내담즙성, 내췌장 액성 및 유해균 억제능을 조사하였다. 특히 분리된 균종 중에서 FF-3가 인공위액과 담즙산에 대한 높은 내성을 나타내었을 뿐만 아니라, Salmonella sp. 과 Escherichia coli에 대하여 높은 항균 활성을 나타내었다. FF-3유래 박테리오신은 그람 양성 및 음성 세균에서 넓은 항균 범위를 나타내었다 본 연구에서 최종선별된 FF-3 균주를 16s rDNA sequence 동정한 결과 Lactobacillus sp.으로 확인되어 FF-3으로 명명하였다.

• 대한수의학회지
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• 제55권2호
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• pp.81-88
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• 2015

This study was conducted to isolate lactic acid bacteria (LAB) from dog intestine and identify potential probiotic strains for canine use. One hundred and one LAB were isolated from feces of 20 healthy dogs. Acid, bile, and heat resistance along with adherence to Caco-2 cells and antimicrobial activity against pathogens were examined. To analyze immunomodulative effects, the production of nitric oxide (NO), TNF-${\alpha}$, and IL-$1{\beta}$ was measured using RAW 264.7 macrophages. Additionally, RAW BLUE cells were used to evaluate nuclear factor-${\kappa}B$ (NF-${\kappa}B$) generation. Ultimately, three strains were selected as canine probiotics and identified as Lactobacillus reuteri L10, Enterococcus faecium S33, and Bifidobacterium longum B3 by 16S rRNA sequence analysis. The L10 and S33 strains showed tolerance to pH 2.5 for 2 h, 1.0% Oxgall for 2 h, and $60^{\circ}C$ for 5 min. These strains also had strong antimicrobial activity against Escherichia coli KCTC 1682, Salmonella Enteritidis KCCM 12021, Staphylococcus aureus KCTC 1621, and Listeria monocytogenes KCTC 3569. All three strains exerted better immunomodulatory effects than Lactobacillus rhamnosus GG (LGG), a well-known commercial immunomodulatory strain, based on NO, NF-${\kappa}B$, IL-$1{\beta}$, and TNF-${\alpha}$ production. These results suggested that the three selected strains could serve as canine probiotics.

• Journal of Pharmaceutical Investigation
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• 제3권3호
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• pp.51-58
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• 1973

It is well known that lactobacillus products are a living bacterial preparation, which acts as the antibacterial and antidiarrhea agents. Beause of the specificity as the living bacterial preparation, this preparation should be remarkably considered to the stabilities in its manufacturing process and storage more than any others. In this report, it has been considered about its stabilities as the following items. 1) Selection of strains. 2) Control of seed strains. 3) Cultivation and its conditions. 4) Dry of microorganisms. 5) Manufacture of products. 6) Products storage. 7) Concerning to administration.

• Journal of Microbiology and Biotechnology
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• 제4권2호
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• pp.151-154
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• 1994

Lactobacillus acidophilus KFRI 233, a strain isolated from human, was selected as a candidate for probiotics due to its excellent growth in MRS broth where no special anaerobic condition is required. Both simultaneous and deferred agar diffusion assays exhibited Lb. acidophilus KFRI 233 to possess an antagonistic effect against Clostridium perfringens. Its antagonistic effect was pH dependent Associative culture of KFRI 233 and Cl. perfringens in broth resulted in maximum 94.04% inhibition of Cl. perfringens. $\beta$-Galactosidase activity of KFRI 233 was higher than other tested strains that are sold as commercial probiotics. Survival of KFRI 233 in pasteurized skim milk (4$^{\circ}C$) and Sherbet mix (-15$^{\circ}C$) after 7 days of storage were 71.9 and 105.5%, respectively.

• 한국미생물·생명공학회지
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• 제25권5호
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• pp.464-467
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• 1997

A shuttle vector, pSHvec, was constructed for Lactobacillus casei (L. casei) YIT 9018 and JM1O9 by recombinant DNA technology. This vector contained the $\beta$-lactamase II gene from Bacillus cereus as a selection marker and replication origins for both Gram(+) and Gram(-) strains. It could transform the wild type L. casei YIT 9018 as well as E. coli JM109 and transformed cells were selected based on antibiotics resistance. The ability of L. casei YIT 9018 for curd formation in 11% skim milk was maintained even after transformation with pSHvec. The vector was stable as long as antibiotics were added to the medium. These results could contribute to the study of lactic acid bacteria for the industrial purpose at a genetic level.

• 미생물학회지
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• 제53권4호
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• pp.344-346
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• 2017

발효 식품에서 널리 발견되는 Lactobacillus plantarum은 환경에 적응하기 위한 다양한 표현형 및 유전적 특성을 가지고 있다. 우리는 사과 주스의 malolactic 발효를 위해 선발한 L. plantarum JBE245 (= KCCM43243) 유전체의 전체 염기서열과 주석을 보고한다. 유전체는 2907개의 암호화 된 영역, 45개의 위유전자, 91개의 RNA 유전자를 포함한 단일 원형 염색체로 구성되었으며 그 크기는 3,262,611 bp였다. 이 유전체는 4개의 malate dehydrogenase 및 3개의 malate permease 유전자들과 함께 다양한 종류의 plantaricins 합성 유전자들을 포함하고 있었다. 이러한 유전적 특성은 발효 동안 사과 주스의 부패 방지와 사과산(malate)의 젖산(lactate)으로의 효율적 전환이 요구되는 균주의 선발 기준과 잘 부합되었다.

• Journal of Dairy Science and Biotechnology
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• 제22권2호
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• pp.119-130
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• 2004

Application of lactic acid bacteria in the markets are divided into four categories: dairy industry, health food industry, animal feed industry and pharmaceutical industries. Recently, Lactobacillus acidophilus have been used in the food industry and have obtained great attention as key cultures for health benefit. Since commercial application of L. acidophilus has become a common practice, characterization of these cultures were made. Futhermore, the strains selected should produce a final dairy product possessing good taste and acceptable body and texture, a selection step that cannot be achieved unless the product is actually manufactured. Conjugated linoleic acid (CLA) have been recognized as antioxidants, cancer inhibitors, cholesterol depressing agents, and growth promoting factors. Food products from ruminants, particularly dairy products, are the major dietary source of CLA f3r humans. The CLA content in yogurt or cheese can be increased by action of the starter cultures. The finding of the production of CLA by food starter culture opens interesting perspectives far the future in producing fermented products enriched in CLA.