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 AK6 sup(T), was isolated from marine aquaculture pond water collected in Andhra Pradesh, India. The fatty acids were dominated by iso-C sub(15:0) iso-C sub(17:0)omega 9c, iso-C sub(15:0) G, iso-C sub(17:0) 3-OH and anteiso-C sub(15:0). Strain AK6 sup(T) 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 AK6 sup(T) was 45.6 mol%. Phylogenetic analysis showed that strain AK6 sup(T) formed a distinct branch within the family Cyclobacteriaceae and clustered with Aquiflexum balticum DSM 16537 sup(T) and other members of the family Cyclobacteriaceae. 16S rRNA gene sequence analysis confirmed that Aquiflexum balticum DSM 16537 sup(T) 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 AK6 sup(T) 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 AK6 sup(T)(=MTCC 11279 sup(T)=JCM 17389 sup(T)). Emended descriptions of the genus Aquiflexum and Aquiflexum balticum are also proposed.