Actomonas aquatica gen. nov., sp. nov., a marine lineage in the phylum Verrucomicrobiota with genetic potential for carbon and nitrogen fixation

A novel bacterial strain, designated WL0086(T), was isolated from a marine sediment sample collected in Lianyungang city, Jiangsu province, PR China. This strain showed the highest 16S rRNA gene sequence similarity to Geminisphaera colitermitum TAV2(T) (92.7 %) of the family Opitutaceae, and all the unclassified cultured and uncultured isolates with similarities >95 % were from marine environments. Cells were Gram-stain-negative, aerobic, non-motile cocci with a size of 0.6-0.8 mu m in diameter. Strain WL0086(T) was positive for both oxidase and catalase, and grew at 20-37 degrees C (optimum, 28 degrees C), with 1.5-11.0 % NaCl (w/v; optimum, 2.5-4.0 %) and at pH 5.0-9.0 (optimum, pH 7.0). The major polar lipid profile of strain WL0086(T) consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylcholine. The major isoprenoid quinone was menaquinone-7 and the predominant fatty acids were iso-C-14 : 0, anteiso-C-15 : 0, C-16 : 0 and C-16 : 1 omega 9c. The complete genome consisted of a chromosome with 6 109 182 bp. The G+C content of genomic DNA was 64.0%. Results of phylogenomic analysis based on the 16S rRNA gene sequence and the whole genome suggested that strain WL0086(T) formed a distinct clade closely neighbouring the members of the family Opitutaceae. On the basis of phylogenetic, phenotypic, and chemotaxonomic evidences, strain WL0086(T) should represent a novel genus of the family Opitutaceae, for which the name Actomonas aquatica gen. nov., sp. nov. is proposed. The type strain is WL0086(T) (=MCCC 1K05844(T)=JCM 34677(T)=GDMCC 1.2411(T)).