Vulcaniibacterium tengchongense gen. nov., sp. nov. isolated from a geothermally heated soil sample, and reclassification of Lysobacter thermophilus Wei et al. 2012 as Vulcaniibacterium thermophilum comb. nov.

Abstract

A thermotolerant Gram-staining negative and aerobic bacterium, designated strain YIM 77520(T), was isolated from a geothermally heated soil sample collected at Rehai National Park, Tengchong, Yunnan Province, South-West China. Cells of the strain were found to be rod-shaped and colonies were light beige and circular. The strain was found to grow in the presence of 0-2% (w/v) total salts (optimum, 0%), at pH 6.0-8.0 (optimum, pH 7.0) and 25-55°C (optimum, 45°C). The only quinone detected was Q-8 and the genomic DNA G+C content was determined to be 66.9mol%. The major fatty acids (>10%) were identified as iso-C16:0 and iso-C15:0. The phospholipids were found to consist of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, five unknown phospholipids and three aminophospholipids. Based on the 16S rRNA gene sequence analysis, strain YIM 77520(T) was found to form a cluster with Lysobacter thermophilus YIM 77875(T) and showed the highest 16S rRNA gene sequence similarity to L. thermophilus YIM 77875(T) (96.0%). These two strains formed a distinct lineage of the family 'Xanthomonadaceae'. On the basis of the morphological and chemotaxonomic characteristics, as well as genotypic data, a new genus, Vulcaniibacterium gen. nov. is proposed with Vulcaniibacterium tengchongense sp. nov. as the type species. The type strain of V. tengchongense sp. nov. is strain YIM 77520(T) (=DSM 25623(T)=CCTCC AB 2011152(T)). Furthermore we propose that L. thermophilus Wei et al. 2012 is reclassified in the new genus as Vulcaniibacterium thermophilum comb. nov. (type strain YIM 77875(T)=CCTCC AB 2012064(T)=KCTC 32020(T)) based on polyphasic data.