Simiduia areninigrae sp. nov., an agarolytic bacterium isolated from sea sand

Abstract

During a study intended to screen for agar-degrading bacteria, strain M2-5 Twas isolated from black sand off the shore of Jeju Island, Republic of Korea. Strain M2-5 Texhibited agarase activity; the β-agarase gene of the isolate had 62% amino acid sequence identity to the β-agarase gene of Microbulbifer thermotolerans JAMB A94 T. The isolate was closely related to members of the genus Simiduia but was clearly discernible from reported Simiduia species, based on a polyphasic analysis. Cells of strain M2-5 Twere Gram-negative, catalase- and oxidase-positive, motile rods. The DNA G+C content was 53.3 mol%. The predominant isoprenoid quinone was Q-8. The major cellular fatty acids were C 17: 1ω8c (25.9 %), summed feature 3 (iso-C 15: 02-OH and/or C 16: 1ω7c; 17.2 %) and C 17: 0(15.0 %). Phylogenetic analysis using 16S rRNA gene sequences showed that strain M2-5 Thad 96.6% gene sequence similarity to Simiduia agarivorans SA1 T, the most closely related type strain of the genus Simiduia. These results suggest that strain M2-5 Trepresents a novel species in the genus Simiduia, for which the name Simiduia areninigrae sp. nov. is proposed; the type strain is M2-5 T(=KCTC 23293 T=NCAIM B 02424 T).