| Autor: |
Tanaka Y; Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan., Aryantini NPD; Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.; Department of PR Science, PT Yakult Indonesia Persada, Jakarta Selatan, Jakarta 12530, Indonesia., Yamasaki E; Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan., Saito M; Kisara Farm Cheese Factory, Haobiminami 10, Shimizu-cho, Kamikawa-gun, Hokkaido 089-0356, Japan., Tsukigase Y; Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan., Nakatsuka H; Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan., Urashima T; Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan., Horiuchi R; Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan., Fukuda K; Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.; Research Center for Global Agromedicine, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan. |
| Abstrakt: |
Two novel probiotic strains of lactic acid bacteria were successfully isolated from the raw milk of dairy Japanese-Saanen goats. Selection criteria for positive candidates were grown on de Man-Rogosa-Sharpe or M17 selective medium at 30, 35, or 42 °C anaerobically, and characterized based on Gram reaction, catalase test, and tolerance to low pH and bile salts. Among the 101 isolated positive candidates, two strains, YM2-1 and YM2-3, were selected and identified as Lacticaseibacillus rhamnosus using 16S rDNA sequence similarity. Culture supernatants of the two strains exhibited antipathogenic activity against Salmonella enterica subsp. enterica serovar. Typhimurium, Shigella sonnei , methicillin-resistant Staphylococcus aureus , methicillin-sensitive Staphylococcus aureus , Listeria monocytogenes , and Escherichia coli O157. The antipathogenic activities were retained to some extent after neutralization, indicating the presence of antipathogenic substances other than organic acids in the culture supernatants. The two strains were sensitive with coincidental minimum inhibition concentrations (indicated in the parentheses hereafter) to ampicillin (0.25 μg/mL), chloramphenicol (4 μg/mL), gentamycin (4 μg/mL), kanamycin (64 μg/mL), streptomycin (16 μg/mL), and tetracycline (4 μg/mL). Furthermore, the two strains were resistant to clindamycin (16 μg/mL) and erythromycin (4 μg/mL). In addition, both YM2-1 and YM2-3 strains showed less unfavorable activities, including bile acid bioconversion, carcinogenic-related enzymes, mucin degradation, plasminogen activation, and hemolysis, than the detection limits of in vitro evaluation methods used in this study. In summary, L. rhamnosus YM2-1 and YM2-3 are highly safe and promising probiotic strains applicable in the dairy industry, and were first isolated from the raw milk of Japanese-Saanen goats. |
