Novosphingobium indicum sp. nov., a polycyclic aromatic hydrocarbon-degrading bacterium isolated from a deep-sea environment

Abstract

A novel polycyclic aromatic hydrocarbon (PAH)-degrading bacterium, strain H25T, which was isolated from deep-sea water of the Indian Ocean, was studied phenotypically, genotypically and phylogenetically. Strain H25T can utilize several PAHs including phenanthrene and fluoranthene as sole carbon sources. The 16S rRNA gene sequence of strain H25T showed the highest similarity with that of Novosphingobium naphthalenivorans TUT562T (96.3%), and showed lower similarities (92.1-96.0%) with other members of the genus Novosphingobium. The major fatty acids of strain H25T were C14:0 2-OH (3.2%), C16:0 (13.6%), C16:1omega7c (5.2%), C18:0 (13.4%) and C18:1omega7c (57.0%), which accounted for 92.3% of the total fatty acids. It had ubiquinone 10 as the major respiratory quinone and spermidine as the major polyamine. All these characteristics were consistent with those of recognized Novosphingobium species. Results of DNA-DNA hybridization experiments and BOX-PCR fingerprint comparisons also indicate that strain H25T represents a novel Novosphingobium species, for which the name Novosphingobium indicum sp. nov. is proposed. The type strain is H25T (=MCCC 1A01080T=CGMCC 1.6784T=LMG 24713T).