Muricauda ochracea sp. nov., isolated from a tidal flat in the Republic of Korea

Abstract

A yellowish-brown-coloured bacterium, designated strain JGD-17^T, was isolated from a tidal flat of Janggu-do, Garorim bay, Taean-gun, Chungcheongbuk-do, Republic of Korea. Cells were Gram-stain-negative, aerobic, non-flagellated and long-rod-shaped. Growth was observed at 20-45 °C (optimum, 25-30 °C), at pH 6.0-10.0 (9.0) and with 1-5 % (w/v) NaCl (1-3 %). Results of 16S rRNA gene sequence analysis indicated that strain JGD-17^T was closely related to Muricauda nanhaiensis SM1704^T (96.1 %), Muricauda olearia CL-SS4^T (95.0 %), Muricauda beolgyonensis BB-My12^T (94.9 %), Muricauda marina H19-56^T (94.7 %) and Muricauda indica 3PC125-7^T (94.5 %). The ranges of values for the average nucleotide identity and digital DNA-DNA hybridization analyses with related strains were 71.3-74.1 % and 16.9-18.2 %. The genomic DNA G+C content was 41.1 mol%. Phylogenetic analysis using the neighbour-joining method showed that strain JGD-17^T formed a clade with Muricauda nanhaiensis SM1704^T, Muricauda lutaonensis CC-HSB-11^T, Muricauda lutea CSW06^T and Muricauda pacifica SM027^T. The major fatty acids were iso-C_{15 : 0} (26.9 %), iso-C_{15 : 1} G (19.5 %) and iso-C_{17 : 0} 3-OH (12.7 %). The predominant respiratory quinone was menaquinone-6. The polar lipids were phosphatidylethanolamine, an unidentified aminolipid, an unidentified phospholipid and two unidentified lipids. On the basis of phylogenetic, phenotypic and chemotaxonomic characteristics, strain JGD-17^T represents a novel species within the genus Muricauda, for which the name Muricauda ochracea sp. nov. is proposed. The type strain is JGD-17^T (=KCTC 72732^T=KACC 21486^T=JCM 33817^T).

Keywords: Muricauda; marine bacteria; polyphasic approach; tidal flats.