Alcanivorax nanhaiticus sp. nov., isolated from deep sea sediment.

A taxonomic study was carried out on strain 19-m-6T, which was isolated from deep sea sediment of the South China Sea during the screening of alkane-degrading bacteria. The isolate was Gram-reaction-negative, and oxidase- and catalase- positive. On the basis of 16S rRNA gene sequence similarity, strain 19-m-6T was shown to belong to the genus Alcanivorax, related to Alcanivorax jadensis T9T (97.5 %), Alcanivorax hongdengensis A-11-3T (97.3  %), A. lcanivorax borkumensis SK2T (96.6 %) and seven other species of the genus Alcanivorax(93.9-95.4 %). Average nucleotide identity values between strain 19-m-6T and A. jadensis T9T, A. hongdengensis A-11-3T and A. borkumensis SK2T were 85.12, 85.87 and 84.35 %, respectively. The estimated DNA-DNA hybridization values between strain 19-m-6T and these three type strains were 22.0, 22.6 and 21.2 %, respectively. Four alkane hydroxylase (alkB) genes were obtained from the draft genome sequence. The G+C content of the chromosomal DNA was 56.44 mol%. The major fatty acids were C16 : 0, C18 : 1ω7c and summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c). The polar lipids were phosphatidylglycerol, phosphatidylethanolamine, one aminolipid, three phospholipids, two glycolipids and two aminophospholipids. According to its phenotypic features, fatty acid composition and 16S rRNA gene sequence, the novel strain fitted well into the genus Alcanivorax, but could be clearly distinguished from all other known Alcanivorax species described to date. The nameAlcanivorax nanhaiticus sp. nov. is thus proposed, with 19-m-6T (=MCCC 1A05629T=KCTC 52137T) as the type strain.