Description of Caldalkalibacillus uzonensis sp. nov. and emended description of the genus Caldalkalibacillus.

Strain JW/WZ-YB58T, a thermophilic (42-64 degrees C), aerobic, alkalitolerant (pH25 degrees C 6.4-9.7), heterotrophic, sporulating, retarded-peritrichously flagellated and slightly curved rod-shaped bacterium, was isolated from the hot spring Zarvarzin II in the East Thermal Field of the Uzon Caldera, Kamchatka (Far East Russia). The isolate tolerated high concentrations of CO. The major membrane phospholipid fatty acids of JW/WZ-YB58T included iso-C15 : 0 (24.5 %), anteiso-C15 : 0 (18.3 %) and iso-C17 : 0 (17.5 %). The G+C content of the genomic DNA is 45 mol% (HPLC method). Based on 16S rRNA gene sequence analysis and physiological properties, isolate JW/WZ-YB58T (=ATCC BAA-1258T =DSM 17740T) is proposed as the type strain of Caldalkalibacillus uzonensis sp. nov. In contrast to the type species Caldalkalibacillus thermarum, a catalase-reaction-positive aerobe, C. uzonensis was catalase-reaction-negative; thus the description of the genus Caldalkalibacillus is emended to include a catalase-reaction-negative species.