Marinihelvus fidelis gen. nov., sp. nov., isolated from marine sediment, and genomic comparison with multiple genera

A Gram-stain-negative, rod-shaped, non-gliding, non-flagellated, yellow, facultatively aerobic bacterial strain, designated as W260(T), was isolated from marine sediment of Xiaoshi Island, Weihai, PR China. The cells of W260(T) were 0.3-0.5 mu m wide and 1.5-2.0 mu m long. Strain W260(T) grows optimally at a temperature of 33 degrees C (range, 15-37 degrees C), pH 8 (range, pH 6.5-9.5) and witha NaCl concentration of 3.0 % (w/v; range, 1-8 %). It has the highest sequence similarity to Thiohalobacter thiocyanaticus DSM 21152(T) (91.7 %), followed by Wenzhouxiangella marina MCCC 1K00261(T) (91.4 %) and Thiohalospira alkaliphila DSM 17116(T) (90.7 %). The similarity between strain W260(T) and the species Thiohalophilus thiocyanatoxydans DSM 16326(T) was 89.4 %. Genome sequencing revealed a genome size of 3 430 000 bp and a DNA G+C content of 64.5 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain W260(T) and W. marina MCCC 1K00261(T) were 69.6 and 16.1-20.6 %, respectively. The predominant quinone was ubiquitin-8, and the major fatty acids were iso-C-14 : 0 and iso-C-16 : 0. The polar lipids consisted of phosphatidylethanolamine, phospholipid, phosphatidylglycerol, diphosphatidylglycerol and four unidentified lipids. Based on phenotypic, phylogenetic and chemotaxonomic information, it was determined that strain W260(T) represents a novel genus and species and it was given the name Marinihelvus fidelis sp. nov. The type strain is W260(T) (=MCCC 1H00471(T)=KCTC 92639(T)).