Psychromonas ingrahamii sp. nov., a novel gas vacuolate, psychrophilic bacterium isolated from Arctic polar sea ice

• DOI: 10.1099/ijs.0.64068-0
• Publication Date: 2006-04-20T18:36:00Z
• Authors: Ann J. Auman; Jennifer L. Breezee; John J. Gosink; Peter Kämpfer; James T. Staley
• Keywords: DNA, Bacterial; 0301 basic medicine; Base Composition; 0303 health sciences; Arctic Regions; Polymers; Fatty Acids; Molecular Sequence Data; Nucleic Acid Hybridization; Genes, rRNA; Sequence Analysis, DNA; DNA, Ribosomal; 6. Clean water; Bacterial Typing Techniques; RNA, Bacterial; 03 medical and health sciences; Microscopy, Electron, Transmission; RNA, Ribosomal, 16S; Environmental Microbiology; Ice Cover; Microscopy, Phase-Contrast; Alaska; Gammaproteobacteria; Phylogeny

A gas vacuolate bacterium, designated strain 37T, was isolated from a sea ice core collected from Point Barrow, Alaska, USA. Cells of strain 37Twere large (6–14 μm in length), rod-shaped, contained gas vacuoles of two distinct morphologies, and grew well at NaCl concentrations of 1–10 % and at temperatures of −12 to 10 °C. The DNA G+C content was 40 mol%. Whole-cell fatty acid analysis showed that 16 : 1ω7ccomprised 67 % of the total fatty acid content. Phylogenetic analysis of 16S rRNA gene sequences indicated that this bacterium was closely related to members of the genusPsychromonas, with highest sequence similarity (96.8 %) toPsychromonas antarctica. Phenotypic analysis differentiated strain 37TfromP. antarcticaon the basis of several characteristics, including cell morphology, growth temperature range and the ability to hydrolyse polymers. DNA–DNA hybridization experiments revealed a level of relatedness of 37 % between strain 37TandP. antarctica, providing further support that it represents a distinct species. The namePsychromonas ingrahamiisp. nov. is proposed for this novel species. The type strain is 37T(=CCUG 51855T=CIP 108865T).