• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1552-1559
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• 2004

In order to evaluate the potential utilization value as a novel probiotic strain, the immunopotentiating activities of the cellular components from Lactobacillus brevis FSB-1 were examined. L. brevis FSB-1 isolated from kimchi were fractionated into the whole cell, cell wall, cytosol and extracellular preparation, and each fraction was examined on intestinal immune system modulating activity in vitro. The cell wall and cytosol preparation showed the relatively high bone marrow cell proliferating activity through Peyer's patch cell in a dose-dependent manner. But these preparations did not directly stimulate the bone marrow cell proliferation. The whole cell, cell wall and cytosol preparation also induced considerable levels of macrophage activation and mitogenicity of murine splenocytes in vitro. The anti-complementary activity (ITCH_(50)) of the cytosol fraction of L. brevis FSB-1 was the most potent in the cellular components, and the activity showed dose dependency. The complement activation by the cytosol fraction of L. brevis FSB-1 occurs via both alternative and classical pathways, which confirmed by the crossed immunoelectrophoresis using anti-human C3.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2237-2240
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• 2017

In the present study, we investigated the effect of tyndallized HY7712 (tHY7712) on the expression of Th cell specific transcription factors and cytokines in whole-body ${\gamma}$-irradiated mice. Oral administration of tHY7712 strongly recovered the ${\gamma}$-irradiation-suppressed expression of helper T (Th) cell- and regulatory T cell-related transcription factors and cytokines, such as T-bet, Foxp3, IFN-${\gamma}$, TNF-${\alpha}$, and IL-10, and suppressed Th2 cell-associated transcription factor and cytokine GATA3 and IL-5, respectively. Furthermore, compared with the control, tHY7712 treatment also restored ${\gamma}$-irradiation-impaired natural killer and cytotoxic T cell activities against YAC-1 tumor cells to 97.8% and 98.6%, respectively.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.398-405
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• 2002

Bifidobacteria have been previously shown to stimulate the immune functions and cytokine production in macrophages and T-lymphocytes. Accordingly, the RAW 264.7 murine macrophage cell line was used to assess the effects of Bifidobacterium on the proliferation and cytoskeleton reorganization of the cells. Cytokine production after exposure to Bifidobacterium was also monitored in both whole cells and cell-free extracts. When RAW 264.7 cells were cultured for 24 h in the presence of heat-killed Bifidobacterium bifidum BGN4, the proliferation of macrophages was slowed down in a dose-dependent manner and cell differentiation was observed by staining with the actin-specific fluorescent dye, rhodamin-conjugated phalloidin. Although EL-4 cells, a T-cell line, stimulated RAW 264.7 cells to produce TNF-${\alpha}$ and IL-6, the stimulatory activity of B. bifidum BGN4 decreased as the EL-4 cell number increased. When disrupted and fractionated BGN4 was used, the whole cell fraction was more effective than the other fractions for the TNF-${\alpha}$ production. In contrast, the cell-free extract exhibited the highest IL-6 production level among the fractions, which was evident even at a $1{\mu}g/ml$ concentration. The current results demonstrate that Bifidobacterium induced differentiation of the macrophages from the fast proliferative stage and that the cytokine production was differentially induced by the whole cells and cell-free extracts. The in vitro approaches employed herein are expected to be useful in further characterization of the effects of bifidobacteria with regards to gastrointestinal and systemic immunity.

• Journal of Pharmacopuncture
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• v.20 no.1
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• pp.18-22
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• 2017

Objectives: The current investigation was carried out to determine the cytotoxic and the antimicrobial activities of methanolic extracts of Plumbago zeylanica. Methods: The stems, leaves, and whole plants were air dried and extracted with methanol by using a Soxhlet extractor for 72 hours at $55-60^{\circ}C$. The antimicrobial activities were determined from the zones of inhibition, which were measured by using the agar well diffusion method, and the cytotoxicity assays were performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay method. Results: The methanolic extracts of the stem and the leaves of Plumbago zeylanica were tested against six bacterial species and nine fungal species, and both extracts showed antimicrobial activity in a dose-dependent manner. The leaf extract of Plumbago zeylanica showed maximum antimicrobial activity against both Staphylococcus aureus sub sp aureus and Fusarium oxysporum. The stem extract was found to be more antimicrobial against the Pseudomonas aeruginosa and the Penicillium expansum species. MTT assays were used to test the cytotoxicity of the whole plant extract in the HCT-116 and the K-562 cell lines, and that extract was shown to have weak cytotoxicity in both cell lines. Conclusion: In the present study, the methanolic stem extracts of Plumbago zeylanica were found to possess remarkable antibacterial activities against many human and agricultural pathogens. The extracts were also found to possess significant antifungal activities, but the antifungal activities were less than the antibacterial activities. Finally, the extracts were found to have weak cytotoxicities in the HCT-116 and the K-562 cell lines.

• KSBB Journal
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• v.8 no.4
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• pp.341-350
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• 1993

As an effort to develop an alternative transportation fuel, the production of methanol from methane gas was studied using the resting cells of an obligatory methanotroph, Methylosinus trichosporium OB3b. The reaction was carried out in high concentration phosphate buffer solutions with the flask-grown cells containing the exclusively cytoplasmic methane monooxygenase (sMMO) activity. The methanol accumulation rate was observed to be 79nmo1/mg·min during the initial 4.5hr. Phosphate-dependent inhibition was found for both sMMO and methanol dehydrogenase (MDH) activities, and the inhibition constants were 185mM and 42mM, respectively. The inhibition mode was noncompetitive. Methanol was found to be very inhibitory to the sMMO activity and the inhibition constant (noncompetitive) was 21mM when propylene was used as substrate. The sMO activity in the resting cells was declined very fast and the rate became very high during the methanol production. These results indicate that the use of M. trichosporium OB3b as a biocatalyst for the methanol production is heavily dependent on the stable maintenance of the whole-cell SMO activity as well as the effective alleviation of product inhibition.

• Animal cells and systems
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• v.4 no.4
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• pp.341-345
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• 2000

It has been very difficult to develop and evaluate efficient fish vaccines because fish immune cells have not been properly characterized. In this study, we investigated the cell-mediated immunological properties of B- and T-like cells in Nile tilapia (Oreochromis nilotica). Surface immunoglobulin negative ($slg^{-}$) cell population proliferated in response to mammalian T-cell mitogens PHA and Con A, while surface immunoglobulin positive ($slg^{+}$) cells responded to the B-cell mitogen LPS. The slg$^{[-10]}$ cells from hemocyanin (HC)-immunized Tilapia, compared to the non-immunized control, reacted more to PHA than to Con A. Unexpectedly, antigen (Ag)-specific response was observed in both $slg^{-}$ and $slg^{-}$cells. Regardless of HC immunization, whole leukocytes from 8 head kidney of fish showed natural killer (NK)cell activity. Especially, NK cell activity was much higher in slg$^{[-10]}$ cells than in slg$^{+}$cells, indicating the possibility that fish NK cells were not at least associated with slg$^{+}$ cell population and not activated by Ag. Further understanding of functional fish immune cells will help to evaluate and develop effective vaccines for fishes and to monitor the course of therapy In infected fishes.hes.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.388-394
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• 2005

In order to investigate the distribution of dominant Bifidobacterium species in intestinal microflora of Korean adults and seniors, SDS-PAGE profiles of whole cell proteins were used for the identification of bifidobacteria. To confirm the reliability of SDS-PAGE, the Bifidobacterium species identified by SDS-PAGE of whole cell proteins were validated by using 16S rDNA sequencing analysis. The results of SDS­PAGE corresponded well with those determined by the analysis of 16S rDNA sequencing. Based on the analysis of SDS-PAGE patterns on unidentified fecal strains which showed positive in fructose-6-phosphate phosphoketolase activity, B. adolescentis, B. longum, and B. bifidum were identified in the feces of adults, and B. adolescentis, B. longum, B. bifidum, B. breve, and B. dentium were identified in those of seniors. In most of the fecal samples tested, the predominant Bifidobacterium species consisted of only a few species, and differences in the distribution and numbers of Bifidobacterium species were observed between adults and seniors. B. adolescentis and B. longum were found to be the most common species in feces of adults, but not in seniors. Accordingly, the distribution and abundance of bifidobacteria in the human intestinal microflora varied depending on the age of hosts.

• YAKHAK HOEJI
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• v.33 no.6
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• pp.365-371
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• 1989

Microbiological conversion of sterols to 17-ketosteroids has been recognized as a source for commercial preparation of steroidal drugs. In order to develop bacterial strains and process with Brevibacterium lipolyticum IAM 1398 capable of converting cholesterol to 1,4-Androstadiene-3,17-dione (ADD) at about 27% yield, we studied on strain improvement, fermentation condition and whole cell immobilization. By using UV and/or NTG as mutagens, a mutant to convert cholesterol to ADD with higher yield than 60% was selected. Better production of ADD was manifested in the case of maltose used as a supplemental carbon source, and yeast extract or soytone as a nitrogen source. Addition of tween 80 (0.05%) as a surfactant beneficial for increasing the productivity. The optimal initial pH of the medium was 6.5 and optimal culture temperature was $30^{\circ}C$. Whole cell immobilization by using carrageenan, agar, alginate and acrylamide was carried out and the activity of conversion was tested. In the case of carrageenan and agar, immobilized cells were active for at least two cycles of fermentation.

• Journal of Microbiology and Biotechnology
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• v.33 no.8
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• pp.1030-1038
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• 2023

Lactiplantibacillus plantarum, previously named Lactobacillus plantarum, is a facultative, homofermentative lactic acid bacterium widely distributed in nature. Several Lpb. plantarum strains have been demonstrated to possess good probiotic properties, and Lpb. plantarum HOM3204 is a potential probiotic strain isolated from homemade pickled cabbage plants. In this study, whole-genome sequencing was performed to acquire genetic information and predict the function of HOM3204, which has a circular chromosome of 3,232,697 bp and two plasmids of 48,573 and 17,060 bp, respectively. Moreover, various oxidative stress-related genes were identified in the strain, and its antioxidant activity was evaluated in vitro and in vivo. Compared to reference strains, the intracellular cell-free extracts of Lpb. plantarum HOM3204 at a dose of 10¹⁰ colony-forming units (CFU)/ml in vitro exhibited stronger antioxidant properties, such as total antioxidant activity, 2,2-diphenyl-1-picrylhydrazyl radical scavenging rate, superoxide dismutase activity, and glutathione (GSH) content. Daily administration of 10⁹ CFU Lpb. plantarum HOM3204 for 45 days significantly improved the antioxidant function by increasing the glutathione peroxidase activity in the whole blood and GSH concentration in the livers of D-galactose-induced aging mice. These results suggest that Lpb. plantarum HOM3204 can potentially be used as a food ingredient with good antioxidant properties.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.280-285
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• 2020

We have developed a constitutive display system of the Pseudomonas fluorescens SIK W1 TliA lipase on the cell surface of Escherichia coli using E. coli outer membrane protein C (OmpC) as an anchoring motif, which is an economical compared to induced system. For the constitutive expression of truncated OmpC-TliA fusion proteins, gntT104 promoter was employed. Cell growth was not affected by over expression of fusion protein during entire culture time, suggesting cell lysis was not a problem. The localization of truncated OmpC-TliA fusion protein on the cell surface was confirmed by immunofluorescence microscopy and measuring whole cell lipase activity. Constitutively displayed lipase was very stable, retaining activity enantioselectivity throughout the five repeated reactions. These results suggest that OmpC from E. coli be a useful anchoring motif for displaying enzymes on the cell surface without any inducers, and this stable surface display system can be employed for a broad range of biotechnological applications.