• Microbiology and Biotechnology Letters
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• v.27 no.1
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• pp.23-27
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• 1999

The development and industrial application of intestinal anaerbic bacteria is highly important in the munufacture of foodstuffs and medical products. We have conducted studies, screening anaerobic intestinal bacteria for acid and bile tolerance and for pathogens suppression in the intestine of swine. One such study was taxonomic in nature and dealt with the isolate's biochemical responses. The results indicated that the BSA-131 strian ioslated. which suppressed various pathogens (13 typical strains), were identified as Lactobacillus reuterii. The strain, which named L. reuterii BSA-131, was able to tolerate acid condition down to pH2 and could also tolerate bile at 5%. The strain exhibited resistance to a range of antibiotics including, cephalexin, erythromycin, flumequine, furazolidine, gentamycin, penicillin G, norfloxacin, spectinomycin, tetracycline, tiamuline, neomycin, chloramphenicol, kanamycin etc.

• KSBB Journal
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• v.32 no.3
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• pp.199-205
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• 2017

The aim of this study was to investigate probiotic characteristics and fermentation profile of selected lactic acid bacteria (LAB) isolated from traditional fermented foods. Antibacterial activity against various pathogens, acid and bile salt tolerance, cell hydrophobicity, and antibiotic resistance were examined. 16S rRNA sequencing was carried out to identify eight presumptive LAB isolates. In general, all identified LAB (Enterococcus faecium MG89-2, Lactobacillus plantarum MG207, L. paracasei MG310, L. casei MG311, Streptococcus thermophilus MG510, L. bulgaricus MG515, L. helveticus MG585, and L. fermentum MG590) showed strong antimicrobial activity. Also, the selected strains were resistant to bile acid up to 3% and their autoaggregation rates were as high as 60%. All selected strains tested were sensitive to chloramphenicol, tetracycline, and ampicillin, whereas resistant to nalidixic acid and kanamycin.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.9
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• pp.1324-1329
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• 2008

This study was conducted to evaluate the potential of the transformed Lactobacillus reuteri Pg4 (T-Pg4) harboring the ${\beta}$-glucanase gene as a poultry probiotic. The probiotic properties of the T-Pg4 strain were evaluated in vitro by their adherence capability and acid and bile salt tolerance, and were evaluated in vivo by their survival and adhesion in the gastrointestinal tract (GIT) of specific-pathogen-free (SPF) chickens. The results showed that the T-Pg4 strain exhibited resistance to acidic conditions and contact with bile salt, and adhered efficiently to the crop and intestinal epithelial cells of chickens in vitro. The T-Pg4 strain also could survive and colonize the gastrointestinal epithelium of the experimental SPF chickens in vivo. In addition, radial enzyme diffusion was used to demonstrate that the Lactobacillus spp. randomly isolated from the GIT of the SPF chickens fed T-Pg4 possessed ${\beta}$-glucanase secretion capability. These findings have demonstrated that the transformed L. reuteri Pg4 survives transit through the stomach and intestine, and may secrete ${\beta}$-glucanase in the chicken GIT. Therefore, it is suggested that this organism could be used as a multifunctional poultry probiotic.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.134-136
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• 2017

Lactobacillus salivarius KLW001, a species of lactic acid bacteria (LAB), was isolated from a weaning piglet in a swine farm, South Korea, to develop an antimicrobial probiotic strain for piglets. Herein, we report the draft genome sequence of the strain. The genome contains 2,326,706 bp with a G+C content of 33.0% in 166 contigs (${\geq}500bp$). From the genome, we found out 4 genes related to antibiotic resistance, 36 genes for phages, 3 genes for bile hydrolysis, and 27 CRISPR spacers.

• Journal of Life Science
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• v.30 no.10
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• pp.896-904
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• 2020

The purpose of this study was to investigate the probiotic characteristics and immune activities of selected lactic acid bacterial (LAB) strains as feed additives in livestock. 301 LAB strains isolated from traditional fermented foods were first assessed for their antibacterial activity potential. Of the 301 isolates, five showed antibacterial activity against five livestock pathogens (Esherichia coli KCCM11234, Listeria monocytogens KCTC3710, Salmonella Typhimurium KCTC1926, Staphylococcus aureus KCCM11593, and Shigella flexneri KCTC2517). The probiotic characteristics of the five selected strains were also investigated by antioxidative activity, hemolysis, bile salt hydrolase, acid resistance and bile tolerance. The SRCM102607 strain was found to have superior probiotic properties and was selected for further experimentation. 16S rRNA gene sequencing showed that SRCM102607 is Pediococcus acidilactici, which was labeled as P. acidilactici SRCM102607 (KCCM 12246P). The survival characteristics of P. acidilactici SRCM102607 in artificial gastrointestinal conditions were assessed under exposed acidic (pH 2.0) and bile (0.5% and 1.0%) conditions. P. acidilactici SRCM102607 was also confirmed to have resistance to various antibiotics, including amikacin, gentamicin, vancomycin, and etc. The TNF-α production by P. acidilactici SRCM102607 was 171.86±4.00 ng/ml. These results show that P. acidilactici RCM102607 has excellent potential for use as a probiotic livestock feed additive.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.519-526
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• 2023

Panax ginseng is one of the most important herbal medicinal plants consumed as health functional food and can be fermented to achieve better efficacy. Lacticaseibacillus, one of the representative genera among lactic acid bacteria (LAB), has also been used as a probiotic material for health functional foods due to its beneficial effects on the human body. To achieve a synergistic effect by using these excellent dietary supplement ingredients together, a novel LAB strain was isolated from the root of 6-year-old ginseng. Through similarity analysis of 16S rRNAs and whole-genome sequences, the strain was confirmed as belonging to the genus Lacticaseibacillus and was named L. casei KGC1201. KGC1201 not only met all safety standards as food, but also showed excellent probiotic properties such as acid resistance, bile salt resistance, and intestinal adhesion. In particular, KGC1201 exhibited superior acid resistance through morphological observation identifying that the cell surface damage of KGC1201 was less than that of the L. casei type strain KCTC3109. Gene expression studies were conducted to elucidate the molecular mechanisms of KGC1201's acid resistance, and the expression of the glycosyltransferase gene was found to be significantly elevated under acidic conditions. Exopolysaccharides (EPSs) biosynthesized by glycosyltransferase were also increased in KGC1201 compared to KCTC3109, which may contribute to better protection of KGC1201 cells from strong acidity. Therefore, KGC1201, with its increased acid resistance through molecular mechanisms and excellent probiotic properties, can be used in health functional foods to provide greater benefit to overall human health and well-being.

• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.871-879
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• 2024

Our group had isolated Bifidobacterium breve strain BS2-PB3 from human breast milk. In this study, we sequenced the whole genome of B. breve BS2-PB3, and with a focus on its safety profile, various probiotic characteristics (presence of antibiotic resistance genes, virulence factors, and mobile elements) were then determined through bioinformatic analyses. The antibiotic resistance profile of B. breve BS2-PB3 was also evaluated. The whole genome of B. breve BS2-PB3 consisted of 2,268,931 base pairs with a G-C content of 58.89% and 2,108 coding regions. The average nucleotide identity and whole-genome phylogenetic analyses supported the classification of B. breve BS2-PB3. According to our in silico assessment, B. breve BS2-PB3 possesses antioxidant and immunomodulation properties in addition to various genes related to the probiotic properties of heat, cold, and acid stress, bile tolerance, and adhesion. Antibiotic susceptibility was evaluated using the Kirby-Bauer disk-diffusion test, in which the minimum inhibitory concentrations for selected antibiotics were subsequently tested using the Epsilometer test. B. breve BS2-PB3 only exhibited selected resistance phenotypes, i.e., to mupirocin (minimum inhibitory concentration/MIC >1,024 ㎍/ml), sulfamethoxazole (MIC>1,024 ㎍/ml), and oxacillin (MIC >3 ㎍/ml). The resistance genes against those antibiotics, i.e., ileS, mupB, sul4, mecC and ramA, were detected within its genome as well. While no virulence factor was detected, four insertion sequences were identified within the genome but were located away from the identified antibiotic resistance genes. In conclusion, B. breve BS2-PB3 demonstrated a sufficient safety profile, making it a promising candidate for further development as a potential functional food.

• Korean Journal of Microbiology
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• v.49 no.3
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• pp.275-281
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• 2013

Probiotics have been reported to benefit human health by modulating immunity, lowering cholesterol, improving lactose tolerance, and preventing some cancer. Once ingested, probiotic microorganisms have to survive harsh conditions such as low pH, protease-rich condition, and bile salts during their passage through the gastro-intestinal (GI) tract colonize and proliferate to exert their probiotic effects. The dual coating technology, by which the bacteria are doubly coated with peptides and polysaccharides in consecutive order, was developed to protect the ingested bacteria from the harsh conditions. The aim of the study was to evaluate the viable stability of a doubly coated blend of four species of Bifidobacterium by comparing its bile/acid resistance and heat viability in vitro with that of the non-coated blend. After challenges with acid, bile salts, heat, and viable cell counts (VVCs) of the dual coated and non-coated blend were determined by cultivation on agar plates or flow cytometric measurement after being stain with the BacLigtht kit$^{TM}$. The results showed that the dual coated blend was much higher resistant to the acidic or bile salt condition than the non-coated blend and heat viability was also higher, indicating that the dual coating can improve the survival of probiotic bacteria during their transit through the GI tract after consumption.

• Journal of Life Science
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• v.28 no.1
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• pp.68-77
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• 2018

The purpose of this study was to isolate the probiotic lactic acid bacteria, and verify the possibility of the final selection strain as probiotic material. For screening of biogenic amines non-producing microorganisms, 42 lactic acid bacteria were isolated from various berries, extract and vinegar grown in Sunchang. Isolates were investigated for various physiological activities such as extracellular enzyme, antimicrobial and antioxidant activities, and 5 isolates were firstly screened. SBB07 was finally selected by analyzing the biogenic amine, and named Lactobacillus brevis SBB07 by 16S rRNA sequencing analysis. Next, SBB07 was assayed for their survival ability when exposed to acidic and bile conditions as well as heat and antibiotic resistance. As a result, SBB07 showed more than 86% and 54% higher survival rate in acidic condition at pH 2.0 and bile resistance with 0.5% oxgall. In addition, SBB07 showed a survival rate of more than 113% in $60^{\circ}C$, and also confirmed that it has resistant to various antibiotics. As a result of confirming the possibility of prebiotics, SBB07 showed the best utilization of GOS as a prebiotic substrate, and utilization of FOS and inulin were also high. These results suggest that SBB07 have good potential for application as probiotic lactic acid bacteria.

• Journal of Life Science
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• v.29 no.6
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• pp.697-704
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• 2019

This study performed to investigate the probiotic properties of lactic acid bacteria 200 strains isolated from traditional fermented foods. Based on being higher tolerance to bile salts and showing higher acid resistance, 4 LAB Strains were selected in the screening experiment; Lactobacillus plantarum SRCM 102224, Lb. plantarum SRCM102227, Lb. paracasei SRCM102329, Lb. paracasei SRCM102343. Antibacterial activity against various pathogens, acid and bile salt tolerance, hemolytic phenomenon, cell surface hydrophobicity, and antibiotic resistance were examined. Among the tested strains, SRCM 102343 (95.9%) was highly observed hydrophobicity compared to Lb. rhmanosus GG (13.4%) as control. In this study, the in vitro adhesion properties of 4 strains of LAB was investigated using human intestinal caco-2 cell cultures. SRCM102329 and SRCM102343showed higher adherence to caco-2 cells than Lb. rhamnosus GG. The antibacterial activities of 4 strains LAB were investigated. the 3 strains showing strongly antimicrobial activity against Escherichia coli ATCC10798, Staphylococcus aureus KCCM11593, Listeria invanovii KCTC3444, Bacillus cereus ATCC11778 and S. enterica serovar. Typhi KCTC1926. These results suggest that selected strains have good probiotic potential for application in functional foods.