Aeromicrobium ponti sp. nov., isolated from seawater

A novel actinomycete strain, designated HSW-1T, was isolated from seawater collected from Hwasun Beach on the coast of Jeju Island, Republic of Korea. The cells were aerobic, Gram-positive, oxidase-negative, catalase-positive, non-motile rods. The colonies were circular, smooth, convex and yellow in colour. The cell-wall peptidoglycan of this organism contained ll-diaminopimelic acid as the diagnostic diamino acid. The polar lipids included phosphatidylinositol, diphosphatidylglycerol, phosphatidylglycerol and three unknown phospholipids. The predominant menaquinone was MK-9(H4). The major fatty acids were C18 : 1 omega 9c, C16 : 0, C16 : 0 2-OH and 10-methyl C18 : 0. The DNA G+C content was 74.0 mol%. A neighbour-joining tree based on 16S rRNA gene sequences showed that this organism falls within the radiation of the genus Aeromicrobium. The closest phylogenetic neighbours were the type strains of Aeromicrobium erythreum (98.2 % 16S rRNA gene sequence similarity), Aeromicrobium alkaliterrae (97.9 %), Aeromicrobium marinum (97.3 %) and Aeromicrobium fastidiosum (97.0 %). The DNA-DNA relatedness values between the novel isolate and its closest relative, A. erythreum DSM 8599T, ranged between 32 and 36 %. On the basis of the phenotypic and DNA-DNA hybridization data, strain HSW-1T represents a novel species of the genus Aeromicrobium, for which the name Aeromicrobium ponti sp. nov. is proposed. The type strain is HSW-1T (=DSM 19178T=KACC 20565T).