Cyclobacterium qasimii sp. nov., a psychrotolerant bacterium isolated from a marine sediment of Kongsfjorden, Svalbard

Abstract

A novel Gram-staining-negative, horseshoe shaped, non-motile bacterium, designated strain M12-11BT, was isolated from a marine sediment sample collected at a depth of 200 m from Kongsfjorden, Svalbard. The colony color was orangish-red due to the presence of carotenoids. The fatty acids were dominated by unsaturated fatty acids (60%), with a high abundance of C16 : 1 ω9c (30%) and C16 : 1ω11c (30%) and the other major fatty acids include anteiso-C14 : 0 (17.7%) and C15 : 0 (22%). Strain M12-11BT contained MK-4 and MK-7 as the major respiratory quinones. The polar lipids consisted of phosphatidylethanolamine (PE), one unknown phospholipid and four unknown aminolipids. Based on the 16S rRNA gene sequence similarity it was ascertained that the closest related species of M12-11BT were Cyclobacterium amurskyense, Cyclobacterium marinum and Cyclobacterium lianum with a sequence similarity of 98.2, 96.8 and 93.3% respectively. Other members of the family 'Cyclobacteriaceae' had sequence similarities of <92.0%. However, DNA-DNA hybridization with Cyclobacterium amurskyense KCTC 12363T and Cyclobacterium marinum DSM 745T showed a relatedness of only 24.5 and 32.5% with respect to strain M12-11BT. Based on the results of DNA-DNA hybridization experiments and phenotypic and chemotaxonomic data it appears that strain M12-11BT represents a novel species of the genus Cyclobacterium, for which the name Cyclobacterium qasimii sp. nov. is proposed. The G+C content of DNA of the strain M12-11BT was 40.5 mol%. The type strain of Cyclobacterium qasimii sp. nov. is M12-11BT (= KCTC 23011T = NBRC 106168T).