Pseudomonas deceptionensis sp. nov., a psychrotolerant bacterium from the Antarctic

During the taxonomic investigation of cold-adapted bacteria from samples collected in theAntarctic area of the South Shetland Islands, one Gram-reaction-negative, psychrotolerant,aerobic bacterium, designated strain M1T, was isolated from marine sediment collected onDeception Island. The organism was rod-shaped, catalase- and oxidase-positive and motile bymeans of a polar flagellum. This psychrotolerant strain grew at temperatures ranging from"46Cto 346C. Phylogenetic studies based on 16S rRNA gene sequences confirmed that Antarcticisolate M1Twas a member of the genusPseudomonasand was located in thePseudomonas fragicluster. 16S rRNA gene sequence similarity values were.98% between 13 type strainsbelonging to thePseudomonas fluorescenslineage. However, phylogenetic analysis ofrpoDgene sequences showed that strain M1Texhibited high sequence similarity only with respect toPseudomonas psycrophila(97.42%) andP. fragi(96.40%) and DNA-DNA hybridizationexperiments between the Antarctic isolate M1Tand the type strains of these two closely relatedspecies revealed relatedness values of 58 and 57%, respectively. Several phenotypiccharacteristics, together with the results of polar lipid and cellular fatty acid analyses, were used todifferentiate strain M1Tfrom related pseudomonads. Based on the evidence of this polyphasictaxonomic study, strain M1Trepresents a novel species, for which the namePseudomonasdeceptionensissp. nov. is proposed. The type strain is M1T(5LMG 25555T5CECT 7677T).