Thermus amyloliquefaciens sp. Nov., isolated from a hot spring sediment sample

Abstract

A Gram-stain-negative, aerobic bacterium, designated strain YIM 77409T, was isolated from the Niujie hot spring in the Eryuan county of Dali, Yunnan province, south-west China. Cells of the strain were rod-shaped and colonies were yellow and circular. The strain grew at pH 6.0-8.0 (optimum, pH 7.0) and 50-70°C (optimum, 60-65°C). The predominant menaquinone was MK-8 and the DNA G + C content was 66.4 mol%. Major fatty acids (>10%) were iso-C15:O and iso-C17:O.The polar lipids consisted of one aminophospholipid, one phospholipid and two glycolipids. 16S rRNA gene sequence analysis showed that strain YIM 77409T formed a cluster with Thermus scotoductus DSM 8553T, Thermus antranikianii DSM 1 2462T, Thermus caliditerrae YIM 77925T and Thermus tengchongensis YIM 77924T, with highest 16S rRNA gene sequence similarity to T. scotoductus DSM 8553T (97.57%). However, DNA-DNA hybridization indicated that strain YIM 77409T should be viewed as a representative of a novel species, as there was only 30.6 + 1.6% reassociation with T. scotoductus DSM 8553T. On the basis of the morphological and chemotaxonomic characteristics, as well as the genotypic data, it is proposed that strain YIM 77409T represents a novel species of the genus Thermus, with the name Thermus amyloliquefaciens sp. nov. The type strain is YIM 77409T (=DSM 25898T=KCTC 32024T).