Hoeflea olei sp. Nov., a diesel-oil-degrading, anoxygenic, phototrophic bacterium isolated from backwaters and emended description of the genus Hoeflea

Abstract

A Gram-stain-negative, diesel-oil-degrading, rod-shaped bacterium (designated JC234T) was isolated from a water sample collected from diesel-oil-contaminated backwaters in Kerala, India. Strain JC234T was oxidase- and catalase-positive, and grew at 20-35 °C and at pH 7-9. Cells contained bacteriochlorophyll-a, hydroxydemethylspheroidene and three unidentified carotenoids. Growth occurred under aerobic, microaerobic and phototrophic anaerobic conditions. Strain JC234T could utilize diesel-oil as a sole source of carbon and energy. Based on the 16S rRNA gene sequence analysis, strain JC234T belonged to the genus Hoeflea within the family Phyllobacteriaceae, and was closely related to Hoeflea alexandrii AM1V30T (98.1% 16S rRNA gene sequence similarity), Hoeflea halophila JG120-1T (97.6%) and other members of the genus Hoeflea ( < 96.4%). Strain JC234T showed 22 ± 2% and 28 ± 1.5% DNA-DNA hybridization with Hoeflea alexandrii KCTC 22096T and Hoeflea halophila KCTC 23107T, respectively. The DNA G + C content of strain JC234T was 54.3 mol %. The major cellular fatty acids were C18:1ω7c/C18:1ω6c,C16:0 and C16:1ω7c/C16:1ω6c. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethylethanolamine and phosphatidylglycerol were the major polar lipids. Strain JC234T contained Q10 as the predominant ubiquinone. On the basis of morphological, physiological, genetic, phylogenetic and chemotaxonomical analyses, we conclude that strain JC234T represents a novel species of the genus Hoeflea, for which the name Hoeflea olei sp. nov. is proposed. The type strain is JC234T (=KCTC 42071T=LMG 28200T). An emended description of the genus Hoeflea is also provided.