Planomicrobium chinense sp. nov., isolated from coastal sediment, and transfer of Planococcus psychrophilus and Planococcus alkanoclasticus to Planomicrobium as Planomicrobium psychrophilum comb. nov. and Planomicrobium alkanoclasticum comb. nov.

Abstract

An aerobic, motile, Gram-positive strain, DX3-12T, was isolated from coastal sediment of the Eastern China Sea in Fujian Province, China, and was identified by means of polyphasic taxonomy. On the basis of 16S rRNA gene sequence similarity, strain DX3-12T was closely related to members of the genera Planomicrobium and Planococcus. 16S rRNA gene sequence similarities between strain DX3-12T and Planomicrobium mcmeekinii, Planomicrobium koreense, Planomicrobium okeanokoites, Planococcus psychrophilus and Planococcus alkanoclasticus were 97·8, 97·8, 97·1, 97·5 and 96·4 %, respectively. Chemotaxonomic and physiological properties of strain DX3-12T supported its affiliation to the genus Planomicrobium. Strain DX3-12T and Planomicrobium mcmeekinii exhibited common phenotypic properties such as the ability to reduce nitrate, but they could be distinguished from each other by physiological and biochemical tests, e.g. acid production from glucose, growth temperature and NaCl concentration requirements. DNA–DNA hybridization further distinguished strain DX3-12T from Planomicrobium mcmeekinii at the species level. Therefore, it is proposed that strain DX3-12T (=AS 1.3454T=JCM 12466T) represents a novel species, Planomicrobium chinense sp. nov. Based on 16S rRNA gene sequence similarities, signature nucleotides, cell morphology and physiological and biochemical properties, Planococcus psychrophilus and Planococcus alkanoclasticus have been transferred to the genus Planomicrobium as Planomicrobium psychrophilum comb. nov. (type strain DSM 14507T=MTCC 3812T) and Planomicrobium alkanoclasticum comb. nov. (type strain NCIMB 13489T=CIP 107718T), respectively.