Halomonas tabrizica sp nov., a novel moderately halophilic bacterium isolated from Urmia Lake in Iran

Abstract

A novel moderately halophilic, Gram-stain negative and aerobic bacterium, designated strain TBZ21(T), was isolated from a water sample of Urmia Lake, Iran. Cells were observed to be non-motile rods with no flagellum, showing positive catalase and oxidase reactions. Strain TBZ21(T) was found to grow at 10-40 A degrees C (optimum, 30 A degrees C), at pH 7-10 (optimum, pH 8) and in the presence of 1-22% (optimum, 10%). The major fatty acids were identified as C-19:0 cyclo omega 8c, C-16:0, Summed features 3 (C-13:0 3-OH and/or iso-C-15:1 H) and 8 (C-18:1 omega 7c and/or C-18:1 omega 6c) and C-12:0 3-OH. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified phosphoaminolipid. The genomic DNA G+C content of strain TBZ21(T) was determined to be 63.3 mol%. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain TBZ21(T) belongs to the genus Halomonas, and shows high sequence similarities to Halomonas fontilapidosi 5CR(T) (99.43%), Halomonas ventosae AL12(T) (98.64%), Halomonas sediminicola CPS11(T) (98.63%) and Halomonas aestuarii Hb3(T) (98.08%), and has low similarities (below 98.0%) with other members of the genus. The values of DNA-DNA relatedness between strain TBZ21(T) and the closely related strains H. fontilapidosi LMG 24455(T) and H. ventosae LMG 26187(T) were 42 +/- 11% and 54 +/- 16%, respectively. On the basis of phenotypic, chemotaxonomic and molecular characteristics, strain TBZ21(T) is concluded to represent a novel species of the genus Halomonas, for which the name Halomonas tabrizica sp. nov. is proposed. The type strain is TBZ21(T) (=LMG 25445(T)=DSM 23018(T)).