Marinomonas agarivorans sp. nov., an agar-degrading marine bacterium isolated from red algae

Abstract

A Gram-stain-negative, aerobic and curved-rod-shaped bacterium, designated QM202^T, was isolated from red algae (<i>Gracilaria blodgettii</i>). Cells of strain QM202^T were 0.2-0.3 µm wide and 1.0-2.5 µm long, catalase-negative and oxidase-positive. The strain exhibited an agar-degrading activity. It was motile by means of a single polar flagellum. Optimal growth occurred at 28-30 °C, pH 7.0-7.5 and in the presence of 2.0-3.0 % (w/v) NaCl. The DNA G+C content was 41.4 mol%. The isoprenoid quinone was identified as Q-8. Phophatidylethanolamine and phosphatidylglycerol were the predominant phospholipids. The dominant fatty acids were C_18:1ω7<i>c</i>, C_16:0 and C_16:1ω7<i>c</i> and/or iso-C_15:0 2-OH. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain QM202^T belonged to the genus <i>Marinomonas</i>. The closest described neighbour in terms of 16S rRNA gene sequence identity was <i>Marinomonas blandensis</i> MED121^T (95.5 %). The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness indicated that strain QM202^T can be considered to represent a novel species, <i>Marinomonas agarivorans</i> sp. nov. The type strain is QM202^T (=KCTC 52475^T=MCCC 1H00145^T).