• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.101-104
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• 1995

We isolated sixty lactic acid bacteria(LAB) from lactic fermented products. Among 60 isolates of LAB, 30 isolates were identified as Lactobacillus casei ssp.(5 strains), Lactobacillus acidophilus(2 strains), Lactobacillus delbrueckii ssp. bulgaricus(6 strains), Lactobacillus plantarum(4 strains), Streptococcus salivarius ssp. thermophilus(11 strains), and Streptococcus faecalis(2 strains). The acid tolerance and bile resistance of 30 LAB were determined. Because the acid tolerance was affected by the initial cell concentrations, the analysis of covariance could be used to remove the effect of initial cells on acid tolerance when testing for differences in acid tolerance among six species. Viability of LAB under acidic condition, pH 3 for 2 hours at $37^{\circ}C$, was significantly different among the species. L. casei and L. acidophilus strains showed great viability, but L. bulgaricus and S. thermophilus strains were very weak in acid tolerance.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.8
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• pp.1352-1359
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• 2020

Objective: Lactobacilli in rabbit intestine is rare and its function in rabbit gut health is not fully understood. The present study aimed to evaluate in vivo the probiotic potential of Lactobacillus casei for suckling rabbits. Methods: Two healthy 5-day-old suckling rabbits with similar weights from each of 12 New Zealand White litters were selected and disturbed to control group and treatment group. All rabbits were artificially fed. The treatment group had been supplemented with live Lactobacillus casei in the milk from the beginning of the trial to 13 days of age. At 15 days of age, healthy paired rabbits were slaughtered to collect intestinal samples. Results: i) Oral administration of Lactobacillus casei significantly increased the proportion of Lactobacilli in the total intestinal bacteria (p<0.01) and obviously reduced that of Escherichia-Shigella (p<0.01); ii) treatment increased the length of vermiform appendix (p<0.05); iii) a higher percentage of degranulated paneth cells was observed in the duodenum and jejunum when rabbits administered with Lactobacillus casei (p<0.01); and iv) the expression of toll-like receptor 9, lysozyme (LYZ), and defensin-7-like (DEFEN) in the duodenum and jejunum was stimulated by supplemented Lactobacillus casei (p<0.05). Conclusion: Orally administered Lactobacillus casei could increase the abundance of intestinal Lactobacilli, decrease the relative abundance of intestinal Escherichia-Shigella, promote the growth of appendix vermiform, stimulate the degranulation of paneth cells and induce the expression of DEFEN and LYS. The results of the present study implied that Lactobacillus casei exhibited probiotic potential for suckling rabbits.

• Journal of Radiation Industry
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• v.6 no.2
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• pp.177-180
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• 2012

The acid and bile tolerance changes of 5 different lactic acid bacteria (LAB; Lactobacillus paracasei, Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus debruekii) with gamma irradiation were evaluated. The abilities of LAB to survive in the acidic conditions at the stomach and the bile acidic conditions at the beginning of the small intestine are the key functions for applying LAB to probiotics. In the results, all of LAB survived more than 50% after incubation in PBS (pH 2.5) for 2 hr, which indicated more than half of LAB are possible to pass through the stomach. However, gamma irradiation decreased the acid tolerances of LAB. The bile tolerances of all bacteria except Lactobacillus acidophilus were observed to survive at a 3% oxgall concentration in MRS, and 1 kGy of gamma irradiation to LAB did not affect any bile tolerances changes. But gamma irradiated Lactobacillus casei and Lactobacillus casei (3 kGy) showed decreasing survival rate with oxgall added MAS agar. In conclusion, gamma irradiation should be applied to yogurt or fermented foods with care because LAB could be changes their properties on acid and bile tolerances.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.907-920
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• 2006

This study was conducted to investigate the inhibitory activity of Lactobacillus spp., Bacillus ssp., and calf fecal isolates against pathogenic Salmonella typhimurium, E. coli, Listeria monocytogenes, and Staphylococcus aureus. Among thirteen strains of Lactobacillus ssp. tested, Lactobacillus helveticus CU631 showed the highest inhibition against three pathogens, whereas Bacillus spp. showed a weak inhibitory activity. Four calf fecal isolates were identified as Lactobacillus pentosus CU13, CU05, Pediococcus pentosaceus CUR02, and Lactobacillus lactis ssp. lactis CUM14. The whole cell and cell wall components of L. rhamnosus CU02 and L. pentosus CU13 were active in the inhibition of L. monocytogenes. The medium components and levels, which affect on the inhibitory activity, were revealed as Tween 80 1.0%, peptone 3.0%, yeast extract 3.0%, glucose 3.0%, beef extract 3.0%, and NaCl 1.0～3.0%, respectively. Inhibitory activity of the supernatant culture medium was not affected by catalase and proteinase K treatment but affected by heat treatment at 80℃ and netralization, which implies that the inhibitory activity is due to the production of organic acids during the growth. L. pentosus CU13 and L. rhamnosus CU02 exhibited broad inhibition spectrum against 16 out of 21 strains including some pathogens. Oral administration of L. rhamnosus CU02 to the mice infected with E. coli O157:H7 was proven to be effective to recover their body weight during the experimental period.

• Journal of Microbiology
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• v.45 no.6
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• pp.515-520
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• 2007

Vaginal lactic acid-producing bacteria of 80 pre-menopausal women were studied by isolation on Blood and DeMan-Rogosa-Sharpe agar, PCR with group-specific primers for Lactobacillus-denaturing gradient gel electrophoresis (DGGE), and PCR with specific primers for V3 region in 16S rRNA-temporal temperature gel electrophoresis (TTGE). Conventional isolation method on media detected only one lactobacillus (Lactobacillus brevis) while TTGE detected only Lactobacillus sp. DGGE detected seven Lactobacillus species; L. coleohominis, L. crispatus, L. iners, L. reuteri, L. rhamnosus, L. vaginalis, and Leuconostoc lactis. L. acidophilus and L. gasseri, which are prevalent in Western women, were not detected in Korean women. Furthermore, L. rhamnosus, Leuc. lactis, L. coleohominis, and Weissella cibaria, which were not previously reported in the vaginal microbiota of Korean women, were detected. The five most prevalent LABs in vaginal microbiota in Korean women were L. iners, Enterococcus faecalis, L. crispatus, Leuc. lactis, and W. cibaria.

• KSBB Journal
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• v.17 no.3
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• pp.311-313
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• 2002

Lactobacillus spry. are Gram-positive bacteria playing important roles in human health. In this study, we successfully isolated the total RNA from the cells broken by glass beads using hot phenol method. Moreover, we were able to omit lysozyme and proteinase K treatment by using glass beads to break cell more efficiently. This method was more rapid and simple when compared to the previous one. Prepared RNA can be used for the transcriptional analysis of Lactobacillus spp.

• KSBB Journal
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• v.15 no.4
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• pp.411-413
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• 2000

A method is described for the rapid and simple isolation of genomic DNA from 3 mL culture of Lactobacillus crispatus KLB46 The isolated DNA using this method was shown to be an excellent substrate for restriction endonclease digestion and PCR. The method is expected to be used in gentic manipulation of L. crispatus KLB46.

• Microbiology and Biotechnology Letters
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• v.18 no.6
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• pp.566-570
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• 1990

Regulation of $\beta$ -galactosidase formation was studied with Lactobacillus sporogenes. Synthesis of the enzyme was effectively induced by isopropyl- $\beta$-D-thiogalactopyranoside (IPTG) or galactose, and to a much lower level by lactose. When 15 mM glucose was added at the different intervals to the cultures that had been in contact with IPTG, the same levels of inhibition of the enzyme synthesis were observed (approximately one-third the differential rate of a control culture without glucose). This suggests that glucose did not interfere with the entry of the inducer into the cells, but interfere with the formation of $\beta$ -galactosidase through catabolite repression. The glucose inhibitory effect was not overcome by adding CAMP or cGMP to the culture media.

• Microbiology and Biotechnology Letters
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• v.27 no.5
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• pp.385-390
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• 1999

To investigate bile salt hydrolase activities of the bacterial strains isolated from fermented milk products, 21 strains of Lactobacillus were tested for their abilities to produced cholic acid from taurocholic and glycocholic acids. The production of cholic acid was measured by HPLC analysis during the growth in broth media for 24hrs. All strains of Lactobacillus acidophilus and L. plantarum deconjugated both taurocholate and glycocholate, whereas none strains of L. delbrueckii subsp. bulgaricus, L. casei subsp. casei, L. casei subsp. rhamnosus, L, reuteri did. L. acidophilus stains isolated from yogurts had the higher decojugation activities on glycocholate than taurocholate, however, L. acidophilus 1009 isolated from the human intestine showed the similar deconjugation activities on both taurocholate and glycocholate.

• Microbiology and Biotechnology Letters
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• v.23 no.5
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• pp.513-518
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• 1995

To evaluate bile salt-tolerance of lactic acid bacteria (LAB, Lactobacillus acidophilus ATCC 4356, Lactobacillus casei IFO 3533, Streptococcus thermnophilus KCTC 2185, Lactobacillus lactis ATCC 4797, and Lactobacillus bulgaricus ATCC 11842), We investigated the survivals, acid production and $\beta $-galactosidase activity of LAB under anaerobic broth system. Cellular permeability of LAB and their cellular retention of $\beta $-galactosidase were also examined in the same system. Although the growth of LAB was slightly suppressed by 0.3% bile salt, they showed normal growth curve. Streptococcus thermophilus KCTC 2185 was significantly more resistant to bile salt than the others. The $\beta $-galactosidase activity from Streptococcus thermophilus KCTC 2185 and Lactobacillus bulgaricus ATCC 11842 and their cellular retention of $\beta $-galactosidase decreased by 0.3% bile salt. The cellular permeability of LAB in the presence of bile salt increased significantly.