A novel bacterium, designated strain C3-17T, was isolated from a natural cave in Jeju, Republic of Korea. Cells of the organism were Gram-stain-negative, strictly aerobic, non-sporulating, non-motile rods. The polar lipids present were phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminophospholipids, an unidentified aminolipid and an unidentified lipid. The sole isoprenoid quinone was Q-8. The predominant fatty acids were C16 : 0 and summed feature 3, and the DNA G+C content was 54.5 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain C3-17T belonged to the family Oxalobacteraceae and was most closely related to the type strains of the genus Collimonas. 16S rRNA gene sequence similarities between the novel isolate and the closest neighbours, Collimonas pratensis Ter91T, Collimonas fungivorans Ter6T and Collimonas arenae NCCB 100031T were 98.7, 98.5 and 98.1 %, respectively. On the basis of data obtained by polyphasic analyses and DNA-DNA hybridization, strain C3-17T (=KACC 19055T=DSM 104040T) represents a novel species of the genus Collimonas, for which the name Collimonasantrihumi sp. nov. is proposed.
Keywords: Collimonas; natural cave; polyphasic analyses; proteobacteria.