Marinifilum flexuosum sp. nov., a new Bacteroidetes isolated from coastal Mediterranean Sea water and emended description of the genus Marinifilum Na et al., 2009.

A facultatively anaerobe, moderately halophilic, Gram-negative, filamentous, non motile and unpigmented bacterium, designated M30(T), was isolated from coastal Mediterranean Sea water in Valencia, Spain. Phylogenetic analysis based on 16S rRNA sequences placed this strain in the phylum "Bacteroidetes" with Marinifilum fragile JC2469(T) as its closest relative with 97% sequence similarity. Average nucleotide identity (ANI) values between both strains were far below the 95% threshold value for species delineation (about 89% using BLAST and about 90% using MUMmer). A comprehensive polyphasic study, including morphological, biochemical, physiological, chemotaxonomic and phylogenetic data, confirmed the independent species status of strain M30(T) within the genus Marinifilum, for which the name Marinifilum flexuosum sp. nov. is proposed. The type strain of Marinifilum flexuosum is M30(T) (=CECT 7448(T)=DSM 21950(T)).