Psychroflexus torquis gen. nov., sp. nov. a psychrophilic species from Antarctic sea ice, and reclassification of Flavobacterium gondwanense (Dobson et al. 1993) as Psychroflexus gondwanense gen. nov., comb. nov

• Published in: Microbiology (Society for General Microbiology) Vol. 144; no. 6; pp. 1601 - 1609
• Main Authors: Bowman, John P, McCammon, Sharee A, Lewis, Tom, Skerratt, Jennifer H, Brown, Janelle L, Nichols, David S, McMeekin, Tom A
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01-06-1998; Society for General Microbiology
• Subjects: Antarctic Regions; Bacteriology; Bacteroides; Biological and medical sciences; DNA, Bacterial - genetics; Fatty Acids - analysis; Flavobacteriaceae; Flavobacterium - chemistry; Flavobacterium - classification; Flavobacterium - genetics; Flavobacterium gondwanense; Flexibacter; Fundamental and applied biological sciences. Psychology; Gram-Negative Bacteria - classification; Gram-Negative Bacteria - genetics; Marine; Microbiology; Microscopy, Phase-Contrast; Nucleic Acid Hybridization; Phylogeny; Psychroflexus gondwanense; Psychroflexus torquis; RNA, Bacterial - genetics; RNA, Ribosomal, 16S - genetics; Seawater - microbiology; Systematics; Antarctica; Antarctic Regions; PS, Antarctica; New genus; Description; Taxonomy; Ribosomal DNA; Phylogeny; Fatty acids; Taxonomic review; Halophily; Psychrophily; 16S-RNA; Bacteria; Chemical composition; New species
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-144-6-1601

Antarctic CRC and School of Agricultural Science, University of Tasmania, GPO Box 252-80, Hobart, Tasmania 7001, Australia
ABSTRACT
Summary: A group of sea-ice-derived psychrophilic bacterial strains possessing the unusual ability to synthesize the polyunsaturated fatty acids eicosapentaenoic acid (20:5.3) and arachidonic acid (20:4.6) belong to the Family Flavobacteriaceae ( Flexibacter-Bacteroides-Flavobacterium phylum), according to 16S rRNA sequence analysis. Surprisingly, the isolates were also found to cluster closely to the moderately halophilic and psychrotrophic species [ Flavobacterium ] gondwanense (sequence similarity 97-8-98-1 %). The whole-cell fatty acid profiles of this group and [ Flavobacterium ] gondwanense were very similar and distinct from other related flavobacteria. The sea ice strains and [ Flavobacterium ] gondwanense differed substantially in terms of ecophysiology, possibly representing divergent adaptations to sympagic and planktonic marine habitats, respectively. Evidence based on phylogeny and fatty acid profiles supports the conclusion that the taxa are close relatives distinct from other bacterial groups. It is thus proposed that the sea ice strains represent a novel taxon designated Psychroflexus torquis gen. nov., sp., nov. (type strain ACAM 623 T ) while [ Flavobacterium ] gondwanense becomes Psychroflexus gondwanense gen. nov., comb. nov.
* Aurhor for correspondence: John P. Bowman. Tel: [phone]. Fax: [phone]. e-mail: [e-mail]
Keywords: Psychroflexus gen. nov., Antarctica, polyunsaturated fatty acids, psychrophilic bacteria, halophilic bacteria