Martelella caricis sp. nov., isolated from a rhizosphere mudflat

Abstract

A novel marine bacterium, designated GH2-8T, was isolated from a rhizosphere mudflat of a halophyte (Carexscabrifolia) in Gangwha Island, Republic of Korea and its taxonomic status was investigated by a polyphasic approach. Cells of strain GH2-8T were Gram-stain-negative, strictly aerobic, oxidase-positive, catalase-positive and non-motile rods that showed growth at 10-30 °C, pH 5-10 and 0-11 % (w/v) NaCl. The predominant respiratory quinone was Q-10. The polar lipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminolipid, an unidentified glycolipid and two unidentified lipids. The major fatty acids were summed feature 8, C16 : 0, C19 : 0cyclo ω8c, C18 : 1ω7c 11-methyl and summed feature 2. The G+C content of the genomic DNA was 53.4 mol%. Comparative analysis of the 16S rRNA gene sequences revealed that the organism belonged to the order 'Rhizobiales' and formed a distinct subline at the root of radiation encompassing members of the genus Martelella. The 16S rRNA gene sequence similarities to the phylogenetic neighbours were Martelella mediterranea (97.1 %), Martelella suaedae (96.9 %), Martelella endophytica (96.6 %), Martelella limonii (96.3 %), Martelella mangrovi (96.1 %) and Martelella radicis (95.5 %). Strain GH2-8T showed low 16S rRNA gene sequence similarities (<93.8 %) to other representatives of the order 'Rhizobiales'. On the basis of the results of phenotypic and phylogenetic analyses, strain GH2-8T (=KACC 19402T=KCCM 90275T=KCTC 62126T=NBRC 113213T) is considered to represent a novel species of the genus Martelella for which the name Martelellacaricis sp. nov. is proposed.