• 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.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.67-73
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• 2008

The potential of the exopolysaccharide (EPS) from a Serratia sp. strain Gsm01 as an antiviral agent against a yellow strain of Cucumber mosaic virus (CMV-Y) was evaluated in tobacco plants (Nicotiana tabacum cv. Xanthi-nc). The spray treatment of plants using an EPS preparation, 72h before CMV-Y inoculation, protected them against symptom appearance. Fifteen days after challenge inoculation with CMV-Y, 33.33% of plants showed mosaic symptoms in EPS-treated plants compared with 100% in the control plants. The EPS-treated plants, which showed mosaic symptoms, appeared three days later than the controls. The enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase polymerase chain reaction (RT-PCR) analyses of the leaves of the protected plants revealed that the EPS treatment affected virus accumulation in those plants. Analysis of phenylalanine ammonia lyase, peroxidase, and phenols in protected plants revealed enhanced accumulation of these substances. The pathogenesis-related (PR) genes expression represented by PR-lb was increased in EPS-treated plants. This is the first report of a systemic induction of protection triggered by EPS produced by Serratia sp. against CMV-Y.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.211-214
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• 2000

Marine Microorganism strain 96CJ10356 produced extracellular polysaccharide (EPS-R) accompanied with cell growth. To improve the production of EPS-R, the effect of aeration rate was tested in a 5-liter jar fermentor with STN medium. The production of EPS-R was increased with aeration rate and after 72 hour cultivation, 12.20 g/l of EPS-R was obtained with an aeration rate of 1.5 vvm and the apparent viscosity was measured to be about 1000 cp with culture broth.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.872-876
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• 2004

The plant pathogen Erwinia pyrifoliae was infected with bacteriophage PEa1(h), which produced a translucent halo plaque when grown on a lawn of E. pyrifoliae. To investigate the function of an exopolysaccharide (EPS)-depolymerase in the growth of E. pyrifoliae, an EPS-depolymerase gene was synthesized using the PCR method and sequenced. The synthesized gene was then transferred to E. pyrifoliae. The transformed E. pyrifoliae did not produce any ooze, and its growth was inhibited. However, the EPS-depolymerase did not appear to induce cell death. Accordingly, the present results suggest that an EPS-depolymerase may be effective in inhibiting the cell growth or infection of the pathogen E. pyrifoliae.

• Journal of Microbiology
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• v.40 no.4
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• pp.260-266
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• 2002

Bacterial strains were isolated from biofilms formed on glass slides submerged in seawater in Dae-Ho Dike. Eight strains showing fast attaching ability were selected and identified. Their exopolysaccharide (EPS)-producing ability and EPS properties were characterized. Based on Microlog System, 4 among the 8 strains were identified as Micrococcus luteus and the rest were Bacillus thuringiensis, Bacillus megaterium,, Staphylococcus saprophyticus and Agrobacterium vitis. A, vitis was reidentified as Sulfitobacter pontiacus based on 16S rDNA sequence data. The amount of water-soluble EPS produced by the 8 strains ranged from 0.114 to 1.329 g$.$l$\^$-1/ and the productivity was negatively correlated with the cell biomass. The molecular weight of the produced EPS ranged from 0.38 to 25.19$\times$10$\^$4/ Da. Glucose and galactose were ubiquitous sugar components. Mannose, ribose, and xylose were also major sugar components. The molecular weight and composition of the EPS showed strain-specific variation.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.820-825
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• 1999

A bacterial strain WN9, which produced a new type of extracellular polysaccharide, was isolated from soil samples. By morphological, physiological, biochemical, and phylogenetic studies, strain WN9 was identified as a Paenibacillus sp. and it was named as Paenibacillus sp. WN9, which produced a high molecular extracellular polysaccharide from glucose. The molecular weight of the exopolysaccharide (EPS-WN9) was estimated to be about 31.5 mega-Da. The FT-IR spectrum of EPS-WN9 revealed typical characteristics of polysaccharides. EPS- WN9 consisted of D-glucose and D-mannose with a molar ratio of 1:1.4 being identified as a neutral sugar component. The acidic component of EPS- WN9 was tyrosine. Rheological analysis of EPS- WN9 revealed that the pseudoplastic property and its apparent viscosity remained stable at various temperatures and pHs.

• 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.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.84-91
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• 2005

We investigated fermentation characteristics and the amount of exopolysaccharide (EPS) produced, and the correlation between EPS and rheological properties in stirred yogurt fermented with Streptococcus thermophilus St-Body 1. The changes of pH and lactic acid concentrations of yogurt showed different patterns according to fermentation temperatures. About 20 to 40% of lactose was utilized during 6 hrs incubation. The higher number of lactic acid bacteria was obtained at 31℃ incubation temperature rather than other incubation temperatures. The higher amount of EPS was produced at 12 hr or 24 hr rather than other incubation period at the same fermentation temperatures. The viscosity continuously increased during the fermentation period, however the syneresis of yogurt was shown the lowest value at 37℃ for 30 hrs incubation. In physical properties, the hardness and adhesiveness increased continuously with decreasing cohesiveness and elasticity as incubation process was extended. The stirred yogurt fermented with S. thermophilus St-Body 1 at 37℃ for 24 hr resulted in the highest score at each sensory evaluation category.

• Korean Journal of Microbiology
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• v.49 no.3
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• pp.297-300
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• 2013

EPS producing bacteria were enumerated in ginseng root system (rhizosphere soil, rhizoplane, inside of root). EPS producing bacterial density of rhizosphere soil, rhizoplane and inside of root were distributed $9.0{\times}10^6$ CFU/g, $7.0{\times}10^6$ CFU/g, and $1.4{\times}10^3$ CFU/g, respectively. Phylogenetic analysis of the 24 EPS producing isolates based on the 16S rRNA gene sequences, EPS producing isolates from rhizosphere soil (RS) belong to genus Arthrobacter (6 strains) and Rhizobium (1 strain). EPS producing bacteria from rhizoplane (RP) were Arthrobacter (6 strains), Rhodococcus (1 strain) and Pseudomonas (1 strain). EPS producing bacteria from inside of root (IR) were categorized into Rhzobium (6 strains), Bacillus (1 strain), Rhodococcus (1 strain), and Pseudomonas (1 strain). Phylogenetic analysis indicated that Arthrobacter may be a member of representative EPS producing bacteria from ginseng rhizosphere soil and rhizoplane, and Rhizobium is typical EPS producing isolates from inside of ginseng root. The yield of EPS was 10.0 and 4.9 g/L by Rhizobium sp. 1NP2 (KACC 17637) and Arthrobacter sp. 5MP1 (KACC 17636). The purified EPS were analyzed by Bio-LC and glucose, galactose, mannose and glucosamine were detected. The major EPS sugar of these strains was glucose (72.7-84.9%).

• Food Science of Animal Resources
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• v.27 no.4
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• pp.538-542
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• 2007

This study was carried out to investigate the toxicity of exopolysaccharides (EPS) from kefir toward MA104 cells and evaluate the inhibitory effects of kefir EPS on rotavirus infection. The results obtained are summarized as follows: Lactic acid bacteria (Lactobacillus fermentum, L. acidophilus, L. brevis) and yeasts (Candida kefyr, Cryptococcus albidus, Pichia ohmeri) were isolated and identified from kefir grain and culture. At 1% EPS, the inhibitory effects of EPS on the infection of MA-104 cells using the MTT assay were $72.52{\pm}6.48%$ for human rotavirus (KU), $36.06{\pm}7.63%$ for bovine rotavirus (NCDV), and $81.66{\pm}1.11%$ for porcine rotavirus (OSU). At 1/128% EPS, the effects were $24.98{\pm}4.58%$ for human rotavirus (KU), $4.71{\pm}6.16%$ for bovine rotavirus (NCDV), and $4.05{\pm}14.90%$ forporcine rotavirus (OSU). EPS isolated from kefir have inhibitory effects on rotaviruses of various serotypes and rotaviruses from different animals.