Tistlia consotensis gen. nov., sp. nov., an aerobic, chemoheterotrophic, free-living, nitrogen-fixing alphaproteobacterium, isolated from a Colombian saline spring

A Gram-negative, aerobic, mesophilic, non-spore-forming, chemotrophic, chlorophyll-lacking, nitrogen-fixing bacterium, designated strain USBA 355 ^T, was isolated from the saline spring 'Salado de Consotá' situated in the Colombian Andes. The non-flagellated cells of strain USBA 355^T were straight to slightly curved rods (0.6-0.7 x 3.0-3.5 μm). Growth occurred optimally at 30°C (growth temperature range between 20 and 40°C), at pH 6.5-6.7 (pH growth range between 5.0 and 8.0) and at 0.5% NaCl (w/v) (range between 0 and 4 %). The major quinone present was Q-10 and the predominant fatty acids identified were C_19:0 cyclo ω8c, C _18:1ω7c and C_18:0. The G+C content of the chromosomal DNA was 71±1 mol%. 16S rRNA gene sequence analysis indicated that strain USBA 355^T formed a distant phylogenetic line of descent with members of the genus Thalassobaculum, family Rhodospirillaceae, class Alphaproteobacteria (90% gene sequence similarity). Comparison of the phylogenetic, chemotaxonomic and physiological features of strain USBA 355 ^T with all other members of the family Rhodospirillaceae suggested that it represents a novel genus and species for which the name Tistlia consotensis gen. nov., sp. nov. is proposed. The type strain of the type species is USBA 355^T (=JCM 15529^T=KCTC 22406^T).