Isolation of a Novel Freshwater Agarolytic Cellvibrio sp. KY-YJ-3 and Characterization of Its Extracellular β-Agarase
A novel agarolytic bacterium, KY-YJ-3, producing extracellular agarase, was isolated from the freshwater sediment of the Sincheon River in Daegu, Korea. On the basis of Gram-staining data, morphology, and phylogenetic analysis of the 16S rDNA sequence, the isolate was identified as Cellvibrio sp. By...
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Published in | Journal of microbiology and biotechnology Vol. 20; no. 10; pp. 1378 - 1385 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Seoul
Korean Society for Applied Microbiology
01.10.2010
한국미생물·생명공학회 |
Subjects | |
Online Access | Get full text |
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Summary: | A novel agarolytic bacterium, KY-YJ-3, producing extracellular agarase, was isolated from the freshwater sediment of the Sincheon River in Daegu, Korea. On the basis of Gram-staining data, morphology, and phylogenetic analysis of the 16S rDNA sequence, the isolate was identified as Cellvibrio sp. By ammonium sulfate precipitation followed by Toyopearl QAE-550C, Toyopearl HW-55F, and Mono-Q column chromatographies, the extracellular agarase in the culture fluid could be purified 120.2-fold with a yield of 8.1%. The specific activity of the purified agarase was 84.2 U/mg. The molecular mass of the purified agarase was 70 kDa as determined by dodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal temperature and pH of the purified agarase were 35℃ and pH 7.0, respectively. The purified agarase failed to hydrolyze the other polysaccharide substrates, including carboxymethyl-cellulose, dextran, soluble starch, pectin, and polygalacturonic acid. Kinetic analysis of the agarose hydrolysis catalyzed by the purified agarase using thin-layer chromatography showed that the main products were neoagarobiose, neoagarotetraose, and neoagarohexaose. These results demonstrated that the newly isolated freshwater agarolytic bacterium KY-YJ-3 was a Cellvibrio sp., and could produce an extracellular β-agarase, which hydrolyzed agarose to yield neoagarobiose, neoagarotetraose, and neoagarohexaose as the main products. |
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Bibliography: | A50 2011001668 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 G704-000169.2010.20.10.001 |
ISSN: | 1017-7825 1738-8872 |
DOI: | 10.4014/jmb.1007.07010 |