Mariniradius saccharolyticus gen. nov., sp. nov., a member of the family Cyclobacteriaceae isolated from marine aquaculture pond water, and emended descriptions of the genus Aquiflexum and Aquiflexum balticum

Abstract

A novel marine, Gram-stain-negative, oxidase- and catalase- positive, rod-shaped bacterium, designated strain AK6T, was isolated from marine aquaculture pond water collected in Andhra Pradesh, India. The fatty acids were dominated by iso-C15 : 0, iso-C17 : 1ω9c, iso-C15 : 1 G, iso-C17 : 0 3-OH and anteiso-C15 : 0. Strain AK6T contained MK-7 as the sole respiratory quinone and phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified phospholipid and seven unidentified lipids as polar lipids. The DNA G+C content of strain AK6T was 45.6 mol%. Phylogenetic analysis showed that strain AK6T formed a distinct branch within the family Cyclobacteriaceae and clustered with Aquiflexum balticum DSM 16537T and other members of the family Cyclobacteriaceae . 16S rRNA gene sequence analysis confirmed that Aquiflexum balticum DSM 16537T was the nearest neighbour, with pairwise sequence similarity of 90.1 %, while sequence similarity with the other members of the family was <88.5 %. Based on differentiating phenotypic characteristics and phylogenetic inference, strain AK6T is proposed as a representative of a new genus and species of the family Cyclobacteriaceae , as Mariniradius saccharolyticus gen. nov., sp. nov. The type strain of Mariniradius saccharolyticus is AK6T ( = MTCC 11279T = JCM 17389T). Emended descriptions of the genus Aquiflexum and Aquiflexum balticum are also proposed.