Caulobacter inopinatus sp. nov., from seawater off O‘ahu, Hawai‘i, and emended description of the genus Caulobacter

A Gram-negative, curved rod and prosthecate bacterium designated as 73W T was isolated from seawater collected at an O‘ahu, Hawai‘i beach. Based on 1,468 nt of the strain’s 16S rRNA gene, the nearest neighbours are Caulobacter segnis ATCC 21756 T (97.4%), Caulobacter rhizosphaerae 7F14 T (97.5%), Caulobacter vibrioides CB51 T (97.3%), ‘Caulobacter zeae’ 410 T (1,402/1,440, 97.4%), Caulobacter mirabilis FWC 38 T (1,398/1,435, 97.4%) and ‘Caulobacter endophyticus’ 774 T (97.3%). Cells are motile by a single polar flagellum. The strain is oxidase and catalase positive, aerobic and microaerophilic and grows between 6 and 39 °C. Major fatty acids in whole cells of 73W T are cis-11-octadecenoic acid/cis-12-octadecenoic acid (50.6%) and hexadecenoic acid (18.2%). The G+C content of the genome is 67.6%. Based on phenotypic and genotypic differences between strain 73W T and extant Caulobacter species, we propose that strain 73W T represents a novel Caulobacter species, for which the name Caulobacter inopinatus sp. nov. is proposed to accommodate strain 73W T as the type strain (DSM 112346 T =LMG 33179 T =NCTC 14601 T ). The description of the genus Caulobacter is emended to reflect the presence in all species of 3-hydroxydodecanoic acid and hexadecanoic acid.