Cyclobacterium halophilum sp. nov., a marine bacterium isolated from a coastal-marine wetland

Abstract

A novel Gram-stain-negative, slightly halophilic bacterium, designated strain GASx41T, was isolated from soil of the coastal–marine wetland Gomishan in Iran. Cells of strain GASx41T were curved, ring-like or horseshoe-shaped rods and non-motile. Strain GASx41T was strictly aerobic, and catalase- and oxidase-positive. The strain was able to grow at NaCl concentrations of 1–10 % (w/v), with optimum growth occurring at 2.5–3 % (w/v) NaCl. The optimum temperature and pH for growth were 25–30 °C and pH 7.5–8.0. On the basis of 16S rRNA gene sequence analysis, strain GASx41T was shown to belong to the genus Cyclobacterium within the phylum Bacteroidetes and showed closest phylogenetic similarity to ‘Cyclobacterium jeungdonense’ HMD3055 (98.0 %). The DNA G+C content of strain GASx41T was 48.1 mol%. The major cellular fatty acids of strain GASx41T were iso-C15 : 0, summed feature 4 (iso-C15 : 0 2-OH and/or C16 : 1ω7c), anteiso-C15 : 0 2-OH, anteiso-C15 : 0 and iso-C17 : 0 3-OH, and its polar lipid pattern consisted of phosphatidylethanolamine, phosphatidylcholine and 12 unknown lipids. The only quinone present was menaquinone 7 (MK-7). All these features confirmed the placement of isolate GASx41T within the genus Cyclobacterium . On the basis of evidence from this study, a novel species of the genus Cyclobacterium , Cyclobacterium halophilum sp. nov., is proposed, with strain GASx41T ( = IBRC-M 10761T = CECT 8341T) as the type strain.