Zhizhongheella caldifontis gen. nov., sp. nov., a novel member of the family Comamonadaceae.

An alkalitolerant, thermotolerant, strictly aerobic and Gram-staining negative bacterial strain, designated YIM 78140(T), was isolated from a water sample in Hehua hot spring, Tengchong, Yunnan province, south-west China. The colonies were light brown, convex and circular. Phylogenetic analysis of the 16S rRNA gene sequence of strain YIM 78140(T) indicated that it was clustered with members of β-Proteobacteria (with the similarity from 96.9 to 93.6 %). Good growth occurred at 40-50 °C, pH 8.0-9.0 and in the presence of 0-3 % (w/v) NaCl. The predominant ubiquinones were Q-8 and Q-9. The major fatty acids were C16:0, C17:0 cyclo, C18:1 ω7c and summed feature 3. The G+C content of genomic DNA was 70.8 mol%. The results of physiological and biochemical characteristics, phylogenetic analysis allowed the phenotypic and genotypic differentiation of strain YIM 78140(T) from its closest phylogenetic neighbours. Therefore, the strain YIM 78140(T) represents a novel genus of the family Comamonadaceae, for which the name Zhizhongheella caldifontis gen. nov., sp. nov. is proposed. The type strain is YIM 78140(T) (= BCRC 80649(T) = KCTC 32557(T)).