• Journal of Microbiology
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• 제45권6호
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• pp.510-514
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• 2007

Twenty-five bacterial strains that secrete mucous materials were isolated from sediment obtained from King George Island, Antarctica. Seven of these strains proved capable of producing cryoprotective exopolysaccharides. The strain KOPRI 21653 was selected for the further study of an anti-ice-nucleating polysaccharide (ANP), which originated from a polar region. KOPRI 21653 was identified as Pseudoalteromonas arctica as the result of 16S rRNA analysis. The exopolysaccharide, P-21653, was purified completely from the KOPRI 21653 cell culture via column chromatography and protease treatment. The principal sugar components of P-21653 were determined to be galactose and glucose, at a ratio of 1:1.5, via GC-MS analysis. The cryoprotective activity of P-21653 was characterized via an E. coli viability test. In the presence of 0.1% (w/v) P-21653, the survival ratio of E. coli cells was as high as 82.6% over three repeated freeze-thaw cycles. The survival ratio decreased drastically to 71.5 and 48.1 %, respectively, in five and seven repeated cycle conditions; however, the survival ratios were greater over three (96.6-92.1%) to seven (100.5-91.6%) freeze-thaw cycles in the presence of 0.5 and 1.0% (w/v) P-21653. In addition, at much lower concentrations (0.1-1.0%), P-21653 resulted in survival ratios (83.1-98.4%) similar to those of two commercially available cryoprotectants ($V_{EG}$ plus X-1000, 92.9% and $V_{M3}$, 95.3%), which were utilized at the recommended concentrations (90%). The biochemical characteristics of exopolysaccharide P-21653 reflect that this compound may be developed as a useful cryoprotectant for use in medical applications and in the food industry.

• Food Science and Biotechnology
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• 제17권3호
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• pp.587-593
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• 2008

Microbial exopolysaccharide (EPS) is a biothickener that can be added to a wide variety of food products, where it serves as a viscosifying, stabilizing, emulsifying, and gelling agent. The objective of this study was to investigate the optimum conditions of pH, incubation temperature, and whey protein concentration (WPC) for EPS production by Lactobacillus rhamnosus ATCC 9595. We found that maximal EPS production was achieved at a pH of 5.5 and temperature of $37^{\circ}C$. At the same fermentation conditions, EPS production was affected by the addition of L. rhamnosus GG (a weak-EPS producer). After growth for 24 hr, total EPS production was $583{\pm}15.4mg/L$ in the single culture system, and $865{\pm}22.6\;mg/L$ in the co-culture system with L. rhamnosus GG. Based on the presence of WPC, EPS production dramatically increased from $583{\pm}15.4$ (under no WPC supplementation) to $1,011{\pm}14.7\;mg/L$ (under supplementation with 1.0% WPC). These results suggest that WPC supplementation and the co-culture systems coupled with small portions of weak-EPS producing strain can play an important role in the enhancement of EPS production.

• 산업기술연구
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• 제25권B호
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• pp.241-251
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• 2005

Exopolysaccharide (CBP) from submerged culture broth of Ganoderma lucidum mycelium and the water soluble (BWS) and water insoluble (BWI) fractions of CBP were prepared by gel filtration. Antitumor activity and effects on proliferation and differenciation of human cancer cells and mouse NIH 3T3 cells were studied. Cytotoxicity test of CBP, BWS and BWI fractions on human cancer cell lines was performed by using sulforhodamine B (SRB) assay. A549 (lung carcinoma), Colo320 DM and HSR (colon carcinoma), and NIH 3T3 cells were used. BWI fraction showed the strongest cytotoxicity (maximum 20% survival) to all human cells tested. However it did not induced apoptosis. Interestingly BWI fraction did not exert cytotoxic effect on NIH 3T3 cells at low concentration of cells ($5{\times}10^4$) but strong toxic effect at high concentration of cells($5{\times}10^5$) which showed transformed morphology. These results suggest that BWI may have cancer cell specific anticancer activity. However, BWI fraction did not effect the amount of pRb and c-myc protein, which implied that BWI fraction did not act at the early stage of signal transduction pathway. CBP fraction induced differenciation of human leukemic cell line, HL-60 cells suggesting the carcinogenesis prevention of normal cell and possible induction of normalization for cancer cell.

• 한국미생물·생명공학회지
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• 제46권1호
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• pp.9-17
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• 2018

The aims of this work were to characterize and determine bioactivities of crude exopolysaccharide (EPS) extract from Bacillus tequilensis PS21 isolated from milk kefir from Kampaeng Petch, Thailand. B. tequilensis PS21 produced 112.1 mg dried EPS/l from initial 80 g/l lactose in modified TSB media at 52 h, with EPS product yield of 8.9 mg EPS/g lactose and specific product yield of 0.3 mg EPS/mg biomass. The FTIR result confirmed EPS to be a protein-bound polysaccharide and SEM analysis showed the morphology to be a grainy appearance with an uneven surface, covered with pores. HPLC analysis determined EPS as a heteropolysaccharide consisting of five sugar units with the following molar ratios; xylose (17.65), glucose (2.54), ribose (1.83), rhamnose (1.23), and galactose (1). Chemical components of this EPS were predominantly carbohydrate at 697.8 mg/g EPS (65%), protein 361.4 mg/g EPS (34%), and nucleic acid 12.5 mg/g EPS (1%). The EPS demonstrated antioxidant activities at 57.5% DPPH scavenging activity, $37.2{\mu}M\;Fe(II)/mg$ EPS and $34.9{\mu}M\;TEAC\;{\mu}M/mg$ EPS using DPPH, FRAP and ABTS assays, respectively. EPS also exhibited anti-tyrosinase activity at 34.9% inhibition. This work represents the first finding of EPS produced by Bacillus sp. from Thai milk kefir which shows potential applications in the production of antioxidant functional foods and whitening cosmetics. However, optimization of EPS production for industrial exploitation requires further study to ascertain the economic potential.

• Journal of Microbiology and Biotechnology
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• 제23권5호
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• pp.681-688
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• 2013

This work is aimed to increase knowledge of the functional exopolysaccharide (EPS) from lactic acid bacteria (LAB) in makgeolli, a Korean fermented rice wine. Among LAB strains isolated from makgeolli, strain M76 was selected as a functional strain producing a bioactive EPS, based on its antioxidative activity on the DPPH radical. The 16S rRNA gene sequencing analysis showed a high sequence similarity (99.0%) with P. acidilactici, but had different biochemical properties with the already known P. acidilactici type strains in the aspect of carbohydrates utilization. The obtained P. acidilactici M76 produced a soluble EPS above 2 g/l. One-step chromatography using gel filtration after ethanol precipitation from the supernatant of P. acidilactici M76 was enough to obtain purified EPS with a single peak, showing a molecular mass of approximately 67 kDa. Componential and structural analyses of EPS by TLC, HPLC, and FT-IR indicated that the EPS is a glucan, consisting of glucose units. The purified EPS had antioxidant activity on the DPPH radical of 45.8% at a concentration of 1 mg/ml. The purified EPS also showed proliferative effect on the pancreatic RIN-m5F cell line and remarkable protection activity on alloxan-induced cytotoxicity. This potent antioxidant and antidiabetic EPS by LAB in makgeolli may contribute to understanding the functionality of makgeolli.

• 한국미생물·생명공학회지
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• 제30권3호
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• pp.264-269
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• 2002

Zoogloea ramigera l15SLR로부터 zooglan다당류의 생산을 위한 최적조건에 관한 연구를 수행하였다 탄소원으로 2.5%의 glucose와 lactose를 이용하였을 때 각각 10.7, 10.5 g/L의 다당류를 생산하였으며 , galactose, white sugar, brown sugar의 경우는 각각 6.4, 6.7, 8.7 g/L의 다당류 생산 을 보였다. 2.5% glucose가 첨가된 제한배지에서 종균 배양액(TSB 배지)을 7ml 이상 접종함으로서 종균 1 ml를 접종 하석 생산된 다당류(2.37 gt) 보다 약 4배의 높은 다당류 생산(10.28 g/L)을 보였다. 종균 배양액을 5 ml이상 접종시에 배양 36시간 이후부터 다당류를 생산하였으며 48시간 배양시에 10g/L이상의 다당류 생산이 가능하였다. 탄소원으로서 또한, 종균 배양액의 흡광도가 1.0~l.7일 경우에 10g/L 이상의 다당류를 생산하였으며, 이 범위를 벗어나는 경우에는 다당류 생산이 저해되었다. 배양액에 rifampicin첨가는 12 g/L이상의 다당류 생산을 보였으며, 다당류 분자량은 1.367$\times$106(g/mol)로서 rifampicin을 가하지 경우 1.711$\times$106(g/mol)와 약간의 차이를 보였다.

• 대한의생명과학회지
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• 제6권1호
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• pp.1-9
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• 2000

Zoogloea ramigera 115SLR로부터 다당류 생합성에 관여하는 유전자를 분리하기 위해서 균주의 genomic DNA로부터 제조된 gene bank로부터 plasmid pLEX3이 얻어졌다. 이로부터 재조합된 5.0 kb DNA fragment를 포함하는 plasmid pLEX10은 다당류의 형태를 변환시키는 유전자를 포함하고 있으며, 이중에서 upstream 영역에 해당하는 1.7 kb DNA fragment가 분리되었다. 1.7 kb DNA 염기서열의 결과로부터 단백질을 인지 할 수 있는 2개의 ORF가 존재하였으며, 50 kDa 단백질을 인지 할 수 있는 ORF3은 X. campestris의 다당류 생합성 유전자들인 gumC와 R. meliloti의 exoP와 아미노산의 동질성을 나타내었다. ORF4는 N-terminal 영역이 결여된 단백질을 인지하며, Thermotoga maritime의 다당류 export에 관여하는 단백질과 동질성을 보였다. Z. ramigera 115SLR and Z. ramigera 115SLR/pLEX10은 각각 slime또는 capsule 형태의 다당류를 생합성하며 이들로부터 생합성된 다당류양은 각각 0.26% (w/v) and 0.16% (w/v)였다.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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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.

• Journal of Microbiology and Biotechnology
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• 제28권8호
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• pp.1282-1292
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• 2018

The exopolysaccharide (EPS) produced by Bacillus amyloliquefaciens GSBa-1 was isolated and purified by ethanol precipitation, and DEAE-cellulose and Sepharose CL-6B chromatographies. The molecular mass of the purified EPS was determined to be 54 kDa. Monosaccharide analysis showed that the EPS was composed of predominantly glucose, and it was further confirmed by NMR spectroscopy to be ${\alpha}-glucan$ that consisted of a trisaccharide repeating unit with possible presence of two ${\alpha}-(1{\rightarrow}3)$ and one ${\alpha}-(1{\rightarrow}6)$ glucosidic linkages. Microstructural analysis showed that the EPS appeared as ellipsoid or globose with a smooth surface. The EPS had a degradation temperature at $240^{\circ}C$. Furthermore, the EPS had strong DPPH and hydroxyl radical scavenging activities, and moderate superoxidant anion scavenging and metal ion-chelating activities. This is the first characterization of a glucan produced by B. amyloliquefaciens with strong antioxidant activity. The results of this study suggest the potential of the EPS from B. amyloliquefaciens GSBa-1 to serve as a natural antioxidant for application in functional products.

• KSBB Journal
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• 제23권1호
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• pp.18-22
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• 2008

EPS 생산량이 다양한 환경 인자 요소에 의해 달라진다는 것이 여러 연구를 통해 알려졌다(1, 5, 10, 11). 본 연구에서는 환경인자를 다음과 같은 요소 (온도, 탄소원, pH, 질소원과 탄소원)로 변화시켜 보면서 관찰하였다. 다양한 환경인자 중 EPS 생산량에 가장 큰 영향을 준 요소는 온도였다. 온도를 $37^{\circ}C$에서 $25^{\circ}C$로 낮추었을 때 EPS 생산량은 2배 이상 증가하는 것을 관찰할 수 있었다(Fig. 3(A)). 탄소원으로 galactose를 사용했을 때 EPS 생산이 가장 효율적이었으나(Fig. 2(A)), 수율 면에서는 lactose를 이용했을 때 가장 효과적이었다(Fig. 2(B)). 그러나 lactose를 사용했을 때 L. paracasei KLB 58의 성장이 매우 저조하였다. 이에 대한 균체량을 증가시킬 수 있는 방법을 모색한다면, EPS 생산하는데 있어 lactose가 휼륭한 탄소원으로 사용될 가능성이 있다고 여겨진다. 반면에, 질소원의 양을 증가시켰을 때의 EPS 생산량의 증가는 거의 변함이 없었다. 5가지 환경요소 (온도, 탄소원, pH, 질소원과 탄소원)를 변화시켜본 인자 중 질소원의 양을 변화시켰을 때 EPS 변화가 가장 적었고, 탄소원의 증가는 EPS 생산의 증가를 가져왔다.