• Applied Biological Chemistry
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• v.51 no.2
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• pp.93-101
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• 2008

This study was conducted to obtain a good probiotic strain of L. acidophilus from infant feces which have the acid and bile tolerance. The selection criteria for the strain included antimicrobial activity, serum cholesterol reduction, resistance to the hydrogen peroxide, angiotensin converting enzyme (ACE) inhibition activity and iron solubility. To this end, five probiotic Lactobacillus strains have been isolated from infant feces. Especially, L. acidophilus SD 105 had strong antimicrobial activity against Listeria sp., high deconjugation activity in the medium which contained 0.5% of glycocholate (GCA) and high resistance to the hydrogen peroxide. L. acidophilus SD 102 showed the highest ACE inhibition activity among the tested cultures and L. acidophilus SD 103 showed iron solubility of more than 70%.

• Journal of Dairy Science and Biotechnology
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• v.33 no.2
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• pp.93-102
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• 2015

The aim of this study was to investigate the physiological characteristics and immunomodulatory activity of Lactobacillus fermentum 450 isolated from raw milk. L. fermentum 450 showed optimum growth at $40^{\circ}C$ and exhibited immunomodulatory effects on $interleukin-1{\alpha}$, tumor necrosis $factor-{\alpha}$, and nitrous oxide at concentrations of >2,500 pg/mL, >2,000 pg/mL, and $11.55{\pm}2.95{\mu}M$, respectively. Of the 16 antibiotics tested, L. fermentum 450 exhibited the highest sensitivity to rifampicin, followed by penicillin-G, and the highest resistance to kanamycin, followed by neomycin and polymyxin B. The strain showed high acid phosphatase activity and was comparatively tolerant to bile juice and acid. Moreover, the strain displayed high resistance to Salmonella Typhimurium (63.86%). These results demonstrate that L. fermentum 450 has potential for use as a probiotic with immunomodulatory activity.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.25-33
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• 2019

Lactobacillus rhamnosus BFE5264, isolated from a Maasai fermented milk product ("kule naoto"), was previously shown to exhibit bile acid resistance, cholesterol assimilation, and adhesion to HT29-MTX cells in vitro. In this study, we re-annotated and analyzed the previously reported complete genome sequence of strain BFE5264. The genome consists of a circular chromosome of 3,086,152 bp and a putative plasmid, which is the largest one identified among L. rhamnosus strains. Among the 2,883 predicted protein-coding genes, those with carbohydrate-related functions were the most abundant. Genome analysis of strain BFE5264 revealed two consecutive CRISPR regions and no known virulence factors or antimicrobial resistance genes. In addition, previously known highly variable regions in the genomes of L. rhamnosus strains were also evident in strain BFE5264. Pairwise comparison with the most studied probiotic strain L. rhamnosus GG revealed strain BFE5264-specific deletions, probably due to insertion sequence-mediated recombination. The latter was associated with loss of the spaCBA pilin gene cluster and exopolysaccharide biosynthetic genes. Comparative genomic analysis of the sequences from all available L. rhamnosus strains revealed that they were clustered into two groups, being within the same species boundary based on the average nucleotide identities. Strain BFE5264 had a sister group relationship with the group that contained strain GG, but neither ANI-based hierarchical clustering nor core-gene-based phylogenetic tree construction showed a clear distinctive pattern associated with the isolation source, implying that the genotype alone cannot account for their ecological niches. These results provide insights into the probiotic mechanisms of strain BFE5264 at the genomic level.

• Journal of Microbiology and Biotechnology
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• v.31 no.8
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• pp.1144-1153
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• 2021

A released exopolysaccharide (rEPS)-producing strain (LM187) with good acid resistance, bile salt resistance, and cholesterol-lowering properties was isolated from Sichuan paocai and identified as Leuconostoc mesenteroides subsp. mesenteroides. The purified rEPS, designated as rEPS414, had a uniform molecular weight of 7.757 × 10⁵ Da. Analysis of the monosaccharide composition revealed that the molecule was mainly composed of glucose. The Fourier transform-infrared spectrum showed that rEPS414 contained both α-type and β-type glycosidic bonds. ¹H and ¹³C nuclear magnetic resonance spectra analysis showed that the purified rEPS contained arabinose, galactose, and rhamnose, but less uronic acid. Scanning electron microscopy demonstrated that the exopolysaccharide displayed a large number of scattered, fluffy, porous cellular network flake structures. In addition, rEPS414 exhibited strong in vitro antioxidant activity. These results showed that strain LM187 and its rEPS are promising probiotics with broad prospects in industry.

• Food Science of Animal Resources
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• v.41 no.2
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• pp.274-287
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• 2021

The purpose of this study is to examine the physiological characteristics and anti-diabetic effects of Pediococcus pentosaceus KI62. The α-amylase and α-glucosidase inhibitory activity of P. pentosaceus KI62 was 94.86±3.30% and 98.59±0.52%, respectively. In MRS broth containing 3% maltodextrin inoculated by P. pentosaceus KI62, the amounts of short chain fatty acids (SCFA) were propionic acid 18.05±1.85 mg/kg, acetic acid 1.12±0.07 g/100 mL, and butyric acid 2.19±0.061 g/kg, and those of medium chain fatty acids (MCFA) were C8 0.262±0.031 mg/kg, C10 0.279±0.021 mg/kg, and C12 0.203±0.009 mg/kg. Compared to sixteen antibiotics, P. pentosaceus KI62 had the highest sensitivity to penicillin-G and rifampicin, as well as the highest resistance to vancomycin and ampicillin. The strain also showed higher leucine arylamidase and valine arylamidase activities than other enzyme activities, but it did not produce β-glucuronidase which is carcinogenic enzymes. The survival rate of P. pentosaceus KI62 in 0.3% bile was 91.67%. Moreover, the strain showed a 98.63% survival rate in pH 2.0. P. pentosaceus KI62 exhibits resistance to Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus at rates of 29.41%, 38.10%, 51.72%, and 50.47%, respectively. P. pentosaceus (23.31%) showed a similar adhesion ability to L. rhamnosus GG, the positive control (24.49%). These results show that P. pentosaceus KI62 has possibility as a probiotic with anti-diabetic effects.

• Food Science of Animal Resources
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• v.43 no.4
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• pp.685-702
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• 2023

Lactic acid bacteria (LAB) are commonly used as probiotics; however, not all LAB strains have the same beneficial effects. To successfully use LAB as probiotics in canines, LAB species should originate from the canine intestinal tract as they display host specificity. The objective of this study was to investigate the phenotypic and genomic traits of potential probiotic LAB isolated from canine fecal samples. Twenty LAB samples were evaluated for their potential probiotic characteristics including resistance to low pH, bile salts, hydrophobicity, auto-aggregation, co-aggregation, adhesion to epithelia or mucosa, and production of inhibitory compounds. Additionally, we evaluated their safety and other beneficial effects on canine health, such as DPPH free radical scavenging, and β-galactosidase. Four strains demonstrated potential probiotic characteristics and were selected: Enterococcus hirae Pom4, Limosilactobacillus fermentum Pom5, Pediococcus pentosaceus Chi8, and Ligilactobacillus animalis FB2. Safety evaluations showed that all strains lacked hemolytic activity, could not produce biogenic amines, and did not carry any pathogenic genes. In addition, L. fermentum Pom5 and P. pentosaceus Chi8 displayed susceptibility to all antibiotics and concordant with the absence of antibiotic resistance genes. Based on their phenotypic and genomic characteristics, L. fermentum Pom5 and P. pentosaceus Chi8 were identified as potential probiotic candidates for canines.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1998.10a
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• pp.83-106
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• 1998

This study was conducted to investigate the probiotics(acid and bile resistance, fermentation properties, viability, cholesterol assimilation, antimicrobial activity, antimutagenicity, and immunoactivation) of the strains of bifidobacteria isolated from healthy Koreans and to investigate the effects of oral administration of Bifidobacterium longum A-2 on the fecal microflora, ${\beta}-glucuronidase$ activity, pH values, Ammonia concentration. The experimental results are summarized as follows: The probiotics were tested for 23 strains including three commer챠al strains as controls. Compared to other strains, strains of A-2 and A-9 showed more acid resistance whereas A-2, A-5, A-13, A-14, A-18 and A-22 showed excellent bile resistances. The properties of bifidobacteria during fermentation were tested. Strains of A-1, A-2, A-3, A-4, A-6, and A-23 resulted in less than pH 4.5 and titratable acidity over 0.90 after 24 hr of fermentation. When the strains of A-2 was grown with glucose, maltose, and fructooligosaccharide, the acetic acid production were higher than with sorbitol and mannitol. The storage stability of the strains of A-2 and A-22 were tesed, indicating the strain A-2 was more stable over 10 days of storage at both $4^{\circ}C$ and $20^{\circ}C$ than A-22. The strains of A-8, A-10, A-11, A-12 and A-20 assimilated more than 30% of cholesterol included in the media. The strains of A-1 and A-2 showed antimicrobial activity against Sta. aureus. The antimutagenicity of the strains were also tested, showing that the mutation was suppressed more by three strains(A-2, A-12, and A-23). In addition, strain A-5 improved immunological activity(phagocytosis, $TNF-{\alpha}$, IL-6) more than other strains. In the effects of oral administration of Bif. longum A-2, the number of fecal bifidobacteria was siginificantly increased(p<0.01) and the level of fecal ${\beta}-glucuronidase$ also was siginificantly reduced(p<0.05). However there were no siginificant differences in the level of Lαctobacilli, Enterobacteriaceae, Clostridium perfringens, pH and ammonia by the administration. The results suggested that Bif. longum A-2 may be met the criteria for probiotics culture.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.1
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• pp.90-95
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• 2005

Lactic acid bacteria were isolated from silage, which produce high level of hydrogen peroxide in cell culture supernatant. The 16S rDNA sequences of the isolate matched perfectly with that of Lactobacillus fermentum (99.9%), examined by a 16S rDNA gene sequence analysis and similarity search using the GenBank database, thus named L. fermentum CS12-1. L. fermentum CS12-1 showed resistance to low pH and bile acid. The production of hydrogen peroxide by L. fermentum CS12-1 was confirmed by catalase treatment and high-performance liquid chromatography. L. fermentum CS12-1 accumulated hydrogen peroxide in culture broth as cells grew, and the highest concentration of hydrogen peroxide reached 3.5 mM at the late stationary growth phase. The cell-free supernatant of L. fermentum CS12-1 both before and after neutralization inhibited the growth of enterotoxigenic Escherichia coli K88 that causes diarrhea in piglets.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.6
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• pp.525-530
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• 2013

Multidrug resistance 3 (MDR3) is expressed on the canalicular membrane of the hepatocytes and plays an important role in protecting the liver from bile acids. Altered ABCB4 gene expression can lead to a rare hepatic disease, low phospholipid-associated cholelithiasis (LPAC). In this study, we characterized 3 ABCB4 mutations in LPAC patients using various in vitro assay systems. We first measured the ability of each mutant to transport paclitaxel and then the mechanisms by which these mutations might change MDR3 transport activity were determined using immunoblotting, cell surface protein biotinylation, and immunofluorescence. Through a membrane vesicular transport assay, we observed that the uptake of paclitaxel was significantly reduced in membrane vesicles expressing 2 ABCB4 mutations, F165I and S320F. Both mutants showed significantly decreased total and cell surface MDR3 expression. These data suggest two missense mutations of ABCB4 may alter function of MDR3 and ultimately can be determined as LPAC-causing mutations.

• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.304-310
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• 1996

For a probiotic yoghurt it is desirable to utilize lactic acid bacteria with a high survival rate and beneficial function to human beings. We have examined a variety of lactic acid bacteria to assess the acid and bile tolerance and antibiotic resistance. In addition, an in vitro culture experiment was performed to evaluate their ability to reduce cholesterol levels in the growth medium. Thirteen strains were selected from in vitro cholesterol assays and fed to Sprague-Dawley rats with a high-cholesterol diet. Among the 13 strains tested, 8 strains were shown to reduce serum cholesterol levels significantly after 24 days of administration in vivo. Rats were fed lyophilized yoghurt powder fermented with a combination of 3 selected strains: Bifidobacterium infantis AM-220, Lactobacillus AM-245, and Styeptococcus MA-1. The levels of total cholesterol and low density lipoprotein were significantly lower (p$\leq$0.05) in rats fed the yoghurt powder compared with control group. These studies suggest that yoghurt fermented with appropriately selected lactic acid bacteria may have a anticholesterolemic effect.