Flavobacterium frigidarium sp. nov., an aerobic, psychrophilic, xylanolytic and laminarinolytic bacterium from Antarctica

A psychrophilic, aerobic bacterium designated A2iT was isolated from marine sediment recovered from shallow waters surrounding Adelaide Island, Antarctica (67S 34H S, 68S 07H W). The organism exhibited xylanolytic and laminarinolytic activity and was halotolerant. Basic characterization showed that it was Gram-negative, non-motile, yellow-pigmented (b,b-carotene-3,3Hdiol) and positive for oxidase and catalase synthesis. Analysis of the 16S rDNA sequence suggests that the organism belongs to the Flexibacter–Cytophaga–Bacteroides phylum. On the basis of its 16S rDNA sequence, the bacterium is 96<8% similar to Flavobacterium columnare ATCC 43622 – its closest relation. The genomic DNA GMC content was 35 mol%. Growth on xylan occurs optimally at 15 SC, though growth also occurs at 0 SC, and the doubling times are 9<6 and 34<8 h, respectively. The maximum growth temperature on xylan is at 24 SC. The bacterium is a neutrophile, growing across the pH range 5<6–8<4 and having an optimum at pH 7<5. Analysis of the 16S rDNA sequence, together with phenotypic, characterization, suggests that the organism is a member of the genus Flavobacterium. DNA–DNA hybridization experiments have shown that it is a novel species; it is proposed, therefore, that the organism be designated as the type strain of Flavobacterium frigidarium sp. nov. (¯ATCC 700810T¯NCIMB 13737T).

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