• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.381-385
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• 2000

The effect and interaction of Ca and B on exopolysaccharide (EPS) synthesis in the diazotrophically growing cyanobacterium. Nostoc spongiaeforme, was investigated. The absence of B inhibited EPS synthesis 1.56-fold ($16\mu\textrm{g}$ glucose equivalent/mg dry weight, 16 d) over the control cells ($25\mu\textrm{g}$ glucose equivalent) grown in medium containing 0.5 mM Ca and $8{\mu}{\textrm}{m}$ B. When B concentration was raised to $40{\mu}{\textrm}{m}$, EPS production was stimulated 1.8-fold. Reduction of Ca concentraion to one-half (0.25 mM) resulted in increased B demand (16$\muM$) by the cells for EPS production at par with the normal sets. However, without Ca, EPS production also increased as B increased. Addition of B to a Ca-free medium stimulated cyanobacterial diazotrophic growth as well as synthesis of Chl a and phycocyanin (0-8 d). The data suggest B-dependent diazotrophic growth during Ca-deficiency and point to and important interactive role of Ca and B in regulation of cyanobacterial EPS synthesis.

• Journal of Microbiology and Biotechnology
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• v.6 no.5
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• pp.321-325
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• 1996

Mutants having altered levels and/or types of EPS in exopolysaccharide biosynthesis were isolated after NTG mutagenesis of Zoogloea ramigera 115SLR. Mutant candidates were classfied with five groups based on the observed characteristics for EPS biosynthesis pattern. The recombinant plasmids pLEX3BS and pLEX3BM were constructed from pEX3B which was previously isolated from genomic DNA of Z. ramigera 115SLR. Plasmid pLEX3BM with a 7.8 kb insert DNA contains an additional 1.8kb DNA fragment which is not present in pLEX3BS containing 13 kb insert DNA. Plasmid pLEX3BM was able to complement the mutation responsible for the changes in morphology of Z. ramigera 115SLR. However, the complementation of EPS negative mutant strains was not successful with pLEX3BM. Plasmid pLEX3BS on the other hand complemented the mutation responsible for the loss of EPS biosynthesis, resulting in the restoration of Z. ramigera 115SLR phenotype. But this plasmid was not able to complement the morphological mutant strain, Z. ramigera 115SLR.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.3
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• pp.181-185
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• 2000

A marine microorganism, strain 96CJ10356 produced exopolysaccharide, designated as EPS-R. To optimize culmize culture conditions for the production of EPS-R, carbon and nitrogen sources, mineral salts, temperature, and pH were exmined. From this study, STN medium for the production of EPS-R was suggested as follows; sucrose 20g, typtone 10g, NaCl 10g, MgSO45g, CaCl21g, KH2PO4 76mg, K2HPO4 83mg, FeCl2 5mg, MnCl2 1mg, NaMoO4 1mg, and ZnCl2 1mg per liter at pH 7.0. About 9.23g/L of EPS-R was obtained from STN medium after cultivation for 120h at $25^{\circ}C$ in a 5-liter jar fermentor with an aearation rate of 0.17 vvm. Apparent viscosity and flocculation activity of the culture broth were increased with the production of EPS-R and the maximal values were 415 cP and 1400 unit/mL against 0.5% activated carbon, respectively.

• IMMUNE NETWORK
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• v.10 no.6
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• pp.230-238
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• 2010

Background: The MK1 strain, a novel bacterial isolate from soft-rotten tissue of the Neungee mushroom, produces copious amounts of exopolysaccharide (EPS) in a dextrose minimal medium. This study examined the molecular characteristics and immunomodulatory activity of MK1 EPS. Methods: The EPS in the culture supernatant was purified by cold ethanol precipitation, and characterized by SDS- PAGE/silver staining and Bio-HPLC. The immunomodulatory activities of the EPS were examined using the mouse monocytic cell line, RAW 264.7 cells. Results: The molecular weights of the purified EPS were rather heterogeneous, ranging from 10.6 to 55 kDa. The EPS was composed of glucose, rhamnose, mannose, galactose, and glucosamine at an approximate molar ratio of 1.00 : 0.8 : 0.71 : 0.29 : 0.21. EPS activated the RAW cells to produce cytokines, such as TNF-${\alpha}$ and IL-$1{\beta}$, and nitric oxide (NO). EPS also induced the expression of co-stimulatory molecules, such as B7-1, B7-2 and ICAM-1, and increased the phagocytic activity. The macrophage-activating activity of EPS was not due to endotoxin contamination because the treatment of EPS with polymyin B did not reduce the macrophage-activating activity. Conclusion: The EPS produced from the MK1 strain exerts macrophage-activating activity.

• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.403-415
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• 2018

The aims of this novel work were to determine the microbial strains and exopolysaccharide (EPS) producers in water kefir from Nakhon Ratchasima Province, Thailand. Thirty-three microbial strains were identified using 16S rRNA gene analysis consisting of 18 bacterial strains, as 9 strains of acetic acid bacteria (AAB), 9 strains of lactic acid bacteria (LAB), and 15 yeast strains. All bacteria were able to produce EPS with a diverse appearance on agar media containing different sugars at a concentration of 8%. Culture supernatants from AAB and LAB showed 31-64% 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity with the highest antioxidant activity of 64% from Acetobacter pasteurianus WS3 and WS6. Crude EPS from A. pasteurianus WS3 displayed the highest ferric reducing antioxidant power at 280 mM $FeSO_4/g$ EPS, greatest anti-tyrosinase activity at 20.35%, and highest EPS production of 1,505 mg EPS/L from 8% sucrose. These microbes offer beneficial health implications and their EPSs can be used as food additives and cosmetic ingredients.

• Journal of Microbiology and Biotechnology
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• v.31 no.5
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• pp.696-704
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• 2021

Levan is an industrially important, functional biopolymer with considerable applications in the food and pharmaceutical fields owing to its safety and biocompatibility. Here, levan-type exopolysaccharide produced by Pantoea agglomerans ZMR7 was purified by cold ethanol precipitation and characterized using TLC, FTIR, ¹H, and ¹³C NMR spectroscopy. The maximum production of levan (28.4 g/l) was achieved when sucrose and ammonium chloride were used as carbon and nitrogen sources, respectively, at 35℃ and an initial pH of 8.0. Some biomedical applications of levan like antitumor, antiparasitic, and antioxidant activities were investigated in vitro. The results revealed the ability of levan at different concentrations to decrease the viability of rhabdomyosarcoma and breast cancer cells compared with untreated cancer cells. Levan appeared also to have high antiparasitic activity against the promastigote of Leishmania tropica. Furthermore, levan had strong DPPH radical scavenging (antioxidant) activity. These findings suggest that levan produced by P. agglomerans ZMR7 can serve as a natural biopolymer candidate for the pharmaceutical and medical fields.

• Journal of Life Science
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• v.25 no.6
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• pp.709-714
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• 2015

The present study isolated seven different kinds of probiotics from various food sources and identified them with Bacillus sp. and Lactobacillus sp. by 16S rDNA sequencing. Their supernatants were prepared after a 24 hr culture, and their effects on nitric oxide (NO) production in mouse RAW 264.7 cells were investigated. Among the treated samples, the culture supernatants of two strains (Bacillus sp. FG-1 and Lactobacillus sp. FG-6) significantly decreased NO production in LPS-activated RAW 264.7 cells. Moreover, they dramatically reduced the expression of pro-inflammatory genes such as COX-2, iNOS, and TNF-α. To examine whether exopolysaccharide (EPS) is responsible for the anti-inflammatory effects of probiotics, EPS was purified from the culture supernatants of Bacillus sp. FG-1 and Lactobacillus sp. FG-6 strains. The EPS treatment produced by FG-1 and FG-6 strains decreased NO production in a dose-dependent manner in LPS-stimulated RAW 264.7 cells without affecting cell viability, while also reducing pro-inflammatory gene expression. Overall, these results suggest that EPS might be one of the key molecules responsible for the anti-inflammatory effects of probiotics.

• 한국당과학회:학술대회논문집
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• 2006.11a
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• pp.37-37
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• 2006

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.415-422
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• 1996

A gene coding for a pyruvyl transferase enzyme involved in exopolysaccharide biosynthesis of Zoogloea ramigera 115SLR was isolated and sequenced. A 4.5 kb of BamHI DNA fragment was isolated from chromosomal DNA using a probe derived from ketal pyruvyl transferase gene of Xanthomonas campestris. The nucleotide sequence of 2.66 kb Pst1/HindIII DNA fragment which was homology with a probe revealed the existence of two complete open reading frames (ORF2 and ORF3) and two partial open reading frames (ORFI and ORF4). The deduced amino acid sequence of ORF3 was homologous to the ketalase (GumL product) of X campestris with 49.5% of similarity and 21.6% of identity. ORF2 on the other hand showed the higher identity with the ketalase (ExoV product) of Rhizobium meliloti (36%) as well as the ketalase of X campestris (23%) than that of ORF3. A gene product of ORF2 was determined with a bacteriophage T7 RNA polymerase/promoter system in E. coli. The molecular weight of protein was 33,500 dalton.

• The Korean Journal of Food And Nutrition
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• v.12 no.3
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• pp.240-245
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• 1999

The purpose of this study was to develop the new microbial bioflocculant available in a food and fer-mentation industal. This study was reported the results of the composition for optimum culture medium and elemental characteristic of crude purification bioflocculant following the previous report(I). The maximum production of the flocculant from Bacillus megaterium was observated in the culture medium containing 2% sucrose 0.3% NaNO3 0.01% tryptone 0.01% beef extract 0.05% MgSO4 ·7 H2O 0.005% CaCO3 Addition of the sucrose as carbon sources and inorganic salt such as MgSO4, CaCO3 significantly increased the production of flocculant more than nitrogen sources. In the result of color reaction of the crude purified bioflocculant it was investgated that anthrone was positive and benedict burette and nin-hydrin was negative. These result were indicated that the flocculant produced from Bacillus megaterium was a kind of exopolysaccharide.