• Asian-Australasian Journal of Animal Sciences
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• 제14권8호
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• pp.1170-1178
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• 2001

This study was conducted to isolate lactobacilli having characteristics to be used as health adjuncts with fermented milk products. Acid tolerant strains were selected in Lactobacilli MRS broth adjusted to pH 4.0 from human faeces. Bile tolerant strains were examined in Lactobacilli MRS broth in which 1.0% bile salt was added. Microhemagglutination tests using swine erythrocytes were performed to select lactobacilli having adherence properties to survive in the intestinal tract. By examination of these characteristics the strain Nam 27, which was isolated from adult faeces, was selected and identified as Lactobacillus salivarius subsp. salivarius based on carbohydrate fermentation and 16S rDNA sequencing.

• Journal of Microbiology and Biotechnology
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• 제22권10호
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• pp.1432-1440
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• 2012

Weissella confusa 31, an isolate from human feces, possesses desirable properties as a probiotic strain, including bile salt resistance. W. confusa 31 is not inhibited by bile salts up to 0.3% concentration. Proteins affected by bile salts (0.05%) were examined by 2-D gel electrophoresis. Our proteomic analyses revealed that the intensities of 29 spots were changed, where 17 increased (including 2 spots observed only under the bile salts stress conditions) and 12 decreased. Proteins were identified by MALDI-TOF mass spectrometry. Proteins increased in the band intensities included adenylate kinase (12.75-fold increase), Clp-like ATP-dependent protease (11.91-fold), 6-phosphogluconate dehydrogenase (10.35-fold), and HSP 70 (5.07-fold). Some of the increased or decreased proteins are also known to be involved in other types of stress responses.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.97-105
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• 2001

The viability of Bifidobacterium longum KCTC 3128, entrapped in calcium alginate beds in simulated gastroenteric juices (gastric and bile salt solution), was tested to evaluate the influences of several parameters (gel concentration, bead size, and initial cell number). The death rate of B. longum in beads after being sequentially exposed to simulated gastric juices and bile salt solution decreased propertionally with increasing both the alginate gel concentration and bead size. The number of initial cell loading in beads affected the numbers of survivors after being exposed to these solutions, while the death rate of the viable cells were not affected. From the results obtained, the influence of entrapment parameters on the survival of bifidobacteria was quantitatively and systematically evaluated by using a mathematical method.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제27권1호
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• pp.71-76
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• 2024

Recurrence of progressive familial intrahepatic cholestasis (PFIC) type II poses challenges during postoperative liver transplant care. Posttransplant patients with PFIC type II risk developing recurrent cholestasis with normal gamma-glutamyl transferase activity, which mimics the original bile salt export pump (BSEP) protein deficiency and is related to a form of immunoglobulin G antibody (anti-BSEP)-mediated rejection. Bortezomib effectively induces apoptosis of actively antibody-producing plasma cells that may have a role in antibodymediated rejection. In this case, we used bortezomib to treat PFIC type II recurrence after liver transplantation in a child.

• Journal of Microbiology and Biotechnology
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• 제28권11호
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• pp.1846-1849
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• 2018

Recent human gut microbiome studies have supported that the genus Bifidobacterium is one of the most beneficial bacteria for human intestinal health. To develop a new probiotic strain for functional food applications, fourteen fecal samples were collected from healthy Koreans and the strain BCBR-583 was newly selected and isolated from a 25-year-old Korean woman's fecal sample using the selective medium for Bifidobacterium. Subsequent fructose-6-phosphate phosphoketolase (F6PPK) test and 16S rRNA gene sequencing analysis of the strain BCBR-583 confirmed that it belongs to B. longum subsp. longum. The stress resistance tests showed that it has oxygen and heat tolerance activities (5- and 3.9-fold increase for 24 h at 60 and 120 rpm, respectively; $78.61{\pm}6.67%$ survival rate at $45^{\circ}C$ for 24 h). In addition, gut environment adaptation tests revealed that this strain may be well-adapted in the gut habitat, with gastric acid/bile salt resistance ($85.79{\pm}1.53%$, survival rate under 6 h treatments of gastric acid and bile salt) and mucin adhesion ($73.72{\pm}7.36%$). Furthermore, additional tests including cholesterol lowering assay showed that it can reduce $86.31{\pm}1.85%$ of cholesterol. Based on these results, B. longum BCBR-583 has various stress resistance for survival during food processing and environmental adaptation activities for dominant survival in the gut, suggesting that it could be a good candidate for fermented food applications as a new probiotic strain.

• Journal of Microbiology and Biotechnology
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• 제30권5호
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• pp.726-732
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• 2020

Indonesian kefir grains are potential sources of lactic acid bacteria (LAB) that may act as probiotics with specific functional properties. In this study we explored the potential of the probiotic and cholesterol-lowering effect of LAB isolated from Indonesian kefir grains obtained from Bogor, Bandung, Jakarta, and Yogyakarta. The results revealed that 10 isolates showed considerable survivability at low pH and bile salt with total cell reduction of ~3 log colony-forming units per milliliter after exposure to pH 2.5 and 0.5% (w/v) bile salt for 1 and 3 h, respectively. All strains exhibited strong antimicrobial activities against pathogenic bacteria and were sensitive to a wide spectrum of antibiotics but exhibited weak bile salt hydrolase activity. Identification based on 16S RNA suggested that nine isolates were Lactobacillus kefiri and one was Lactobacillus rhamnosus. The ability of the isolates to reduce cholesterol from the media varied, ranging from 22.08% to 68.75% with the highest reduction shown by L. kefiri JK17. The ability to remove cholesterol from the media decreased greatly in resting and dead cells, ranging from 14.58% to 22.08% in resting cells and from 7.89% to 18.17% in dead cells. It can be concluded that Indonesian kefir grains contain LAB potentially acting as probiotics capable of reducing cholesterol. The cholesterol-lowering effect especially occurs when the cells are metabolically active.

• Journal of Animal Science and Technology
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• 제48권2호
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• pp.307-314
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• 2006

Kefir로부터 1차적으로 평판배양법을 이용하여 생장이 가장 우수한 효모를 분리하였고, 이 균은 API 20C kit를 이용한 당발효성 결과에서 99.8%의 상동성을 가진 Candida kefyr로 동정되었다. Candida kefyr 균주는 효소기질을 첨가하여 굳힌 PDA 평판 실험에서 특히 phytase 와 amylase의 분비능력이 높은 것으로 관찰되었고 cellulase와 xylanase, protease 활성은 낮게 나타났다. 균체를 균질화하여 효소활성을 측정하였을 때, amylase와 phytase, cellulase 활성이 0.339±1.12, 0.052±0.88, 0.051±0.78 μmole/min/mg로 비교적 높은 활성을 보였다. Candida kefyr는 pH2에서 초기균수의 0.7%로 감소되는 것으로 보이나 Saccharomyces cerevisiae보다는 약 100배 정도 높게 생존하는 것으로 나타나 내산성이 비교적 강한 것으로 판단되었다. Candida kefyr는 1.0%의 bile salt의 존재하에서도 초기 균수의 약 97.2%를 유지하는 것으로 나타났으며, 이는 86.1%인 Saccharomyces cerevisiae 보다 내담즙산에 강한 것으로 나타났다. 열 안정성을 측정한 경우는 Candida kefyr는 60℃에서 5.0×109 CFU/ml 정도로 약 35.7%가 잔존하는 것으로 조사되었으며 Saccharomyces cerevisiae 보다는 10배 이상 높은 내열성을 유지하였다. 13가지의 항생제중 Candida kefyr의 항생제 내성을 측정한 경우는 10ppm neomycin과 150ppm 이상의 clopidol에서는 억제되었으나 11가지 항생제에는 억제되지 않는 내성을 보였다. 이상의 결과로부터 본 연구에서 분리된 Candida kefyr 균주는 강한 내산성 및 내열성과 항생제 내성을 나타냈으며 소화관련 효소의 활성들도 높게 나타나 가축용 생균제로 충분히 유용성이 있는 것으로 사료되었다.

• 한국미생물·생명공학회지
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• 제48권3호
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• pp.276-286
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• 2020

Probiotics are live microorganisms that, when administered in adequate amounts, confer health benefits to the host. This study was conducted for the isolation of potential lactic acid bacteria (LAB) with probiotic properties from goat milk and yogurt. Several tests were conducted in vitro using the standard procedures for evaluating the inhibitory spectra of LAB against pathogenic bacteria; tolerance to NaCl, bile salt, and phenol; hemolytic, milk coagulation, and bile salt hydrolase activities; gastrointestinal transit tolerance; adhesion properties; and antibiotic susceptibility. Among 40 LAB strains screened according to culture characteristics, five isolates exhibited antagonistic properties. Three were identified as Pediococcus acidilactici, and two were identified as Enterococcus faecium, exploiting 16S rRNA gene sequencing. All the isolates succeeded in the gastrointestinal transit tolerance assay and successively colonized mucosal epithelial cells. Based on the results of these in vitro assays, both P. acidilactici and E. faecium can be considered as potential probiotic candidates.

• Asian-Australasian Journal of Animal Sciences
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• 제21권9호
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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.

• Journal of Microbiology and Biotechnology
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• 제26권2호
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• pp.402-407
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• 2016

Lactic acid bacteria have been identified to be effective in reducing cholesterol levels. Most of the mechanistic studies were focused on the bile salt deconjugation ability of bile salt hydrolase in lactic acid bacteria. However, the mechanism by which Lactobacillus decreases cholesterol levels has not been thoroughly studied in intact primate cells. 3-Hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) is the vital enzyme in cholesterol synthesis. To confirm the effect of probiotic Lactobacillus strains on HMGCR level, in the present study, human hepatoma HepG2 cells were treated with Lactobacillus strains, and then the HMGCR level was illustrated by luciferase reporter assay and RT-PCR. The results showed that the level of HMGCR was suppressed after being treated with the live Lactobacillus strains. These works might set a foundation for the following study of the antihyperlipidemic effects of L. acidophilus, and contribute to the development of functional foods or drugs that benefit patients suffering from hyperlipidemia diseases.