Ureibacillus composti sp. nov. and Ureibacillus thermophilus sp. nov., isolated from livestock-manure composts

Abstract

Two Gram-negative, rod-shaped, thermophilic bacterial strains, HC145(T) and HC148(T), were isolated from a compost sample from a compost facility in Ichon, Korea. Sequencing of the 16S rRNA genes of HC145(T) and HC148(T) and comparative analyses of the resulting sequences clearly showed that these strains had a phylogenetic affiliation to the genus Ureibacillus. The level of 16S rRNA similarity between the two novel strains was 98.4 % and the levels of sequence similarity between them and existing Ureibacillus species were 97.8-98.1 (HC145(T)) and 97.4-98.7 % (HC148(T)). The DNA-DNA reassociation values between the two strains and the type strains of Ureibacillus species ranged from 38 to 51 %. The polar lipid profiles for both isolates consisted of phosphatidylglycerol, diphosphatidylglycerol, phospholipids and glycolipids of unknown composition. The major quinones were MK-8, MK-9 and MK-7, the peptidoglycan type was l-Lys<--d-Asp and the main cellular fatty acid was iso-C(16 : 0). The DNA G+C contents of strains HC145(T) and HC148(T) were 42.4 and 38.5 mol%, respectively. On the basis of the data from this polyphasic study, strains HC145(T) and HC148(T) represent members of the genus Ureibacillus, for which the names Ureibacillus composti sp. nov. and Ureibacillus thermophilus sp. nov., respectively, are proposed. The type strain of U. composti is HC145(T) (=KACC 11361(T) =DSM 17951(T)) and the type strain of U. thermophilus is HC148(T) (=KACC 11362(T) =DSM 17952(T)).