Abstract
The taxonomic position of an actinomycete designated AMA 120(T), isolated from mangrove sediment, was clarified by phenotypic, chemotaxonomic and phylogenetic studies. The 16S rRNA gene sequence revealed that strain AMA 120(T) was most closely related to Gordonia rhizosphera NBRC 16068(T) (98.9 %), Gordonia polyisoprenivorans NBRC 16320(T) (98.1 %) and Gordonia bronchialis NBRC 16047(T) (98.1 %). A fragment of the gyrB gene of strain AMA 120(T) formed a distinct phyletic line with G. rhizosphera NBRC 16068(T) (95.4 %). Strain AMA 120(T) contained meso-diaminopimelic acid, arabinose and galactose as cell-wall components, and MK-9(H-2) was the predominant menaquinone. The polar lipid profile for this strain consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and two unidentified phospholipids. Mycolic acid was present. The major fatty acids were C-16:0, C-18:1 omega 9C and summed feature 3 (C-16:1 omega 7c and/or C-16:1 omega 6c). The DNA-DNA relatedness values between AMA 120(T) and close species were below 70 %. There was an obvious distinction in the average nucleotide identity distribution between strain AMA 120(T) and its closely related strains at around 75-92%. The DNA G+C content of strain AMA 120(T) was 66.6 mol%. These results, coupled with the phenotypic and chemotaxonomic data, indicated that strain AMA 120(T) represents a novel species of the genus Gordonia, for which the name Gordonia sediminis sp. nov. is proposed. The type strain is AMA 120(T) (=TBRC 7109(T) =NBRC 113236(T)).
