• KSBB Journal
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• v.18 no.5
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• pp.404-407
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• 2003

Two recombinant Escherichia coli strains, GCSC6576 harboring a plasmid pSYL107 containing the Ralstonia eutropha polyhydroxyalkanoate (PHA) biosynthesis genes and a fadR atoC mutant LS5218 harboring a plasmid pJC4 containing the Alcaligenes latus PHA biosynthesis genes were compared for their ability to synthesize poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV) from whey. The 3HV fraction could be increased by acetic acid induction and oleic acid supplementation in flask cultures of recombinant E. coli GCSC6576. With the pH-stat fed-batch culture of recombinant E. coli LS5218, we obtained a cell concentration, a P(3HB-co-3HV) concentration, a P(3HB-co-3HV) content, and a 3HV fraction of 31.8 g/L, 10.6 g/L, 33.4%, and 6.26 mol%, respectively in 39 h.

• Journal of Physiology & Pathology in Korean Medicine
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• v.36 no.1
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• pp.1-6
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• 2022

The tuber of Pinellia ternata (Thunb.) Brei (TPT) used in traditional Oriental medicine for the treatment of cough, sputum, vomiting, and insomnia, possesses antioxidant, antibacterial, and anti-inflammatory effects. Although recent studies have reported the anticancer effects of TPT in several cancer cells, it is still unclear whether TPT regulates tumor-associated macrophage (TAM) characterized by the immunosuppressive M2 macrophage phenotype. Our results showed that the ethanol extract of TPT (ETPT) suppressed the migration of RAW264.7 mouse macrophage cells and THP-1 human monocytes differentiated into macrophages towards the conditioned media (CM) collected from lung cancer cells, suggesting that ETPT would attenuate the recruitment of macrophages into tumors. In addition, ETPT suppressed the interleukin (IL)-4 or IL-6-induced M2 macrophage polarization in RAW264.7 cells. ETPT treatment not only downregulated the mRNA expression of M2 macrophage markers including arginase-1, mannose receptor C type 1 (MRC-1), and IL-10, but also inhibited the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and STAT6, general regulators of M2 macrophage polarization. Finally, the transwell assay results showed that the CM from M2-polarized RAW264.7 cells increased the migration of mouse lewis lung carcinoma (LLC) cells, while those from RAW264.7 cells co-treated with ETPT and IL-6 significantly reduced the migration of LLC cells. Taken together, our observations clearly demonstrate that ETPT suppressed the cancer cell migration by regulating macrophage recruitment and M2 macrophage polarization.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.207-210
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• 2000

Pseudomonas oleovorans was cultivated to produce medium chain length polyhydroxyalkanoates (MCL-PHA) fram octanoic acid and ammonium nitrate as carbon and nitrogen source, respectively, by a pH-stat fed-batch culture technique. The octanoate concentration of the culture broth was maintained below 4 g/L by feeding the mixture of octanoic acid and ammonium nitrate when the culture pH rose above high limit. The effect of the ratio of octanoic acid to ammonium nitrate (C/N ratio) in the feed on the PHA production was examined. The final cell concentrations of 62.5, 54.7, and 9.5 g/L, PHA contents of 62.9, 75.1, and 67.6% of dry cell weight, and productivities of 1.03, 0.632, and 0.161 g/L/h were obtained when the C/N ratio in the feed were 10, 20, and 100 g octanoic acid/g ammonium nitrate, respectively.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.626-632
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• 2005

A new bacterium BL-2 excreting a novel cationic polyglucosamine biopolymer was isolated from the spoiled leaves of Chinese cabbage and identified as Enterobacter sp. BL-2. The isolated Enterobacter sp. BL-2 was cultivated in pH-stat fed-batch culture using acetic acid as the feeding stock at pH 8.0, resulting in 17.11 g/l of cells and 1.53 g/l of an extracellular biopolymer after 72 h. The excreted biopolymer was purified by a three-step procedure, involving ethanol precipitation and deproteinizations, to a nearly homogeneous state, and its molecular weight was found to be 106 kDa. It was composed of glucosamine, rhamnose, and galactose at a molar ratio of 86.4:1.6:1.0, respectively, indicating a rarely found novel high-glucosamine-containing biopolymer. The FT-IR and $^{13}C-NMR$ spectra of the novel cationic polyglucosamine biopolymer PGB-l revealed a close identity with chitosan from crab shell. It can effectively flocculate various suspended solids, including kaolin clay, $Ca(OH)_2,\;Al_{2}O_3$, active carbon, microbial cells, and acidic dyes.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.10a
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• pp.246.1-246
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• 1979

A glucose-limited “pH-stat” continuous culture study of Lactobacillus bulgaricus NLS-4 in an anaerobic condition showed the marked effects of environmental pH on end products, fermentation blances and bioenergetic aspects of the organism. Lactic acid was the major end product of fermentation with minor products, such as acetic acid, formic acid and ethanol throughout the pH range tested. In acidic conditions below pH 6.5, a typi-cal pattern of homofermentation was revealed whereas in alkaline conditions, the metabolic pattern was changed from homofermentation to heterofermentation and led to acquire much energy. This metabolic change was likely due to the pH-dependent lactate dehydrogenase activity. Molar growth yields (Yglc=35.5-44.4) and YATP, $18.5\pm2.5$ in average which was 80％ higher than the value ever postulated seemed to be accounted for less requirement of maintenance energy of the organism in the culture conditions.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.753-759
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• 2002

$\beta$-Cyclodextrin glucanotransferase ($\beta$-CGTase) was overproduced extracellularly using recombinant E. coli by transforming the plasmid pECGT harboring a secretive signal peptide. The $\beta$-CGTase gene of alkalophilic Bacillus firmus var alkalophilus was inserted into the high expression vector pET20b(+) containing a secretive pelB signal peptide, and then transformed into E. coli BL2l(DE3)pLysS. The optimum culture conditions fer the overproduction of $\beta$-CGTase were determined to be TB medium containing 0.5% (w/v) soluble starch at post-induction temperature of $25^{\circ}C$. A significant amount of $\beta$-CGTase, up to 5.83 U/ml, which was nine times higher than that in the parent strain B. firmus var. alkalophilus, was overproduced in the extracellular compartment. A pH-stat fed-batch cultivation of the recombinant E. coli was also performed to achieve the secretive overproduction of $\beta$-CGTase at a high cell density, resulting in production of up to 21.6 U/ml of $\beta$-CGTase.

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1248-1254
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• 2019

Identification of novel probiotic strains is of great interest in the field of functional foods. Specific strains of heat-killed bacteria have been reported to exert immunomodulatory effects. Herein, we investigated the immune-stimulatory function of heat-killed Lactobacillus plantarum KCTC 13314BP (LBP). Treatment with LBP significantly increased the production of $TNF-{\alpha}$ and IL-6 by macrophages. More importantly, LBP was able to enhance the phagocytic activity of macrophages against bacterial particles. Activation of p38, JNK, ERK, $NF-{\kappa}B$, and STAT3 was involved in the immunomodulatory function of LBP. LBP treatment significantly increased production of $TNF-{\alpha}$ by bone marrow-derived macrophages and splenocytes, further confirming the immunostimulatory effect of LBP in primary immune cells. Interestingly, the immunomodulatory effects of LBP were much stronger than those of Lactobacillus rhamnosus GG, a well-known probiotic strain. These results indicate that LBP can be a promising immune-enhancing functional food agent.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.507-511
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• 1995

In an attempt to improve the productivity of ${\beta}-galactosidase$ from Bacillus sp. A1, which was isolated from soil and has remarkably higher transgalactosylation activity than lactose hydrolysis activity, a chemical mutation procedure using N-methyl-N'-nitro-N-nitrosoguanidine followed by selection was conducted. The final selection, designated as Bacillus sp. A4442, turned out to show a substantially increased enzyme productivity. Catabolite repression by glucose and lactose requirement as an inducer for the enzyme biosynthesis, which were shown in the parent strain, was markedly diminished; instead it was found out that galactose acts as another inducer. Because pH of medium, one of the most important factors for cell growth as well as enzyme production, is closely related with the sugar concentration during culture, it was kept in the optimum range of $6.5{\sim}7.5$; for this the initial glucose concentration was adjusted to be 0.5% which was thereafter maintained by the controlled pumping-in of lactose using the pH-stat technique. By doing so, we were able to increase the productivity of ${\beta}-galactosidase$ with high transgalactosylation activity up to $44\;unit/m{\ell}-broth$.

• Journal of Pharmacopuncture
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• v.22 no.4
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• pp.253-259
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• 2019

Objectives: It is reported that tumor-associated macrophages (TAMs) contribute to cancer progression by promoting tumor growth and metastasis. The purpose of this study is to investigate the effect of different fractions of Adenophora triphylla var. japonica (AT) on the polarization of macrophages into the M2 phenotype, a major phenotype of TAMs. Methods: We isolated hexane, ethyl acetate, and butanol fractions from crude ethanol extract of AT. The cytotoxicity of AT in RAW264.7 cells was examined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RAW264.7 cells were polarized into the M2 phenotype by treatment with interleukin (IL)-4 and IL-13. The expression of M2 macrophage marker genes was detected by reverse transcription polymerase chain reaction (RT-PCR). The phosphorylation level of signal transducer and activator of transcription 6 (STAT6) was investigated by western blot analysis. The migration of Lewis lung carcinoma (LLC) cells was examined by transwell migration assay using conditioned media (CM) collected from RAW264.7 cells as a chemoattractant. Results: Among various fractions of AT, the ethyl acetate fraction of AT (EAT) showed the most significant suppressive effect on the mRNA expression of M2 macrophage markers, including arginase-1, interleukin (IL)-10 and mannose receptor C type 1 (MRC-1), up-regulated by treatment of IL-4 and IL-13. In addition, EAT suppressed the phosphorylation of STAT6, a critical regulator of IL-4 and IL-13-induced M2 macrophage polarization. Finally, the increased migration of Lewis lung carcinoma (LLC) cells by CM from M2-polarized RAW264.7 cells was reduced by CM from RAW264.7 cells co-treated with EAT and M2 polarization inducers. Conclusion: We demonstrated that EAT attenuated cancer cell migration through suppression of macrophage polarization toward the M2 phenotype. Additional preclinical or clinical researches are needed to evaluate its regulatory effects on macrophage polarization and anti-cancer activities.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.1
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• pp.61-66
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• 2014

Lung cancer is still the number one cause of death from cancer worldwide. The clinical effect of platinum-based chemotherapy for non-small cell lung cancer is constrained by the resistance to drug. To overcome chemo-resistance, various modified treatment including combination therapy has been used, but overall survival has not been improved yet. In this study, chemo-resistant lung cancer cells, A549/Cis and H460/Cis, were developed by long-term exposure of cells to cisplatin and the proliferative capability of these resistant cells was verified to be reduced. We found cytotoxic effect of epigallocatechin gallate (EGCG), a major catechin derived from green tea, on both the parental lung cancer cells, A549 and H460, and their cisplatin resistant cells, A549/Cis and H460/Cis. ELISA and Western blot analysis revealed that EGCG was able to increase interlukine-6 (IL-6) production per cell, whereas its downstream effector Signal transducers and activators of transcription 3 (STAT3) phosphorylation was not changed by EGCG, indicating that IL-6/STAT3 axis is not the critical signaling to be inhibited by EGCG. We next found that EGCG suppresses the expression of both Axl and Tyro 3 receptor tyrosine kinases at mRNA and protein level, explaining the cytotoxic effect of EGCG on lung cancer cells, especially, regardless of cisplatin resistance. Taken together, these data suggest that EGCG impedes proliferation of lung cancer cells including their chemo-resistant variants through downregulation of Axl and Tyro 3 expression.