Kurthia huakuii sp. nov., isolated from biogas slurry, and emended description of the genus Kurthia

Abstract

A novel facultatively anaerobic bacterium, designated strain LAM0618T, was isolated from biogas slurry samples collected from the large-scale anaerobic digester of Modern Farming Corporation in Hebei Province, China. Cells of strain LAM0618T were Gram-stain-positive, motile, non-spore-forming and short-rod-shaped. The optimal temperature and pH for growth were 30 °C and 7.0, respectively. The strain did not require NaCl for growth but tolerated up to 70 g NaCl l−1. The major fatty acids of strain LAM0618T were iso-C15 : 0, anteiso-C15 : 0, iso-C14 : 0, C16 : 0 and C18 : 0. The predominant menaquinones of strain LAM0618T were menaquinone 7 (MK-7) and menaquinone 6 (MK-6). The main polar lipids of strain LAM0618T were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and six unknown glycolipids. The genomic DNA G+C content was 41 mol% as determined by the T m method. Analysis of the 16S rRNA gene sequence revealed that strain LAM0618T was a member of the genus Kurthia , and was most closely related to ‘ Kurthia massiliensis’ DSM 24639, Kurthia zopfii DSM 20580T, Kurthia gibsonii DSM 20636T and Kurthia sibirica DSM 4747T, with 96.9, 95.7, 95.6 and 94.9 % sequence similarity, respectively. Based on its phenotypic and genotypic properties, strain LAM0618T is suggested to represent a novel species of the genus Kurthia , for which the name Kurthia huakuii sp. nov. is proposed. The type strain is LAM0618T ( = ACCC 06121T = JCM 19187T).