Martelella radicis sp nov and Martelella mangrovi sp nov., isolated from mangrove sediment

Two Gram-stain-negative, non-motile, rod-shaped bacterial strains, designated BM5-7(T) and BM9-1(T) were isolated from soil of the root system of a mangrove forest. Phylogenetic analysis based on 16S rRNA gene sequences showed that the two isolates belong to the genus Martelella. The chemotaxonomic characteristics of these isolates included the presence of C-19:0 cyclo omega 8c and C-18:1 omega 7c as the major cellular fatty acids and Q-10 as the dominant ubiquinone. The genomic DNA G+C contents of strains BM5-7(T) and BM9-1(T) were 61.0 and 59.7 mol% (HPLC method), respectively. The 16S rRNA gene sequence similarity between the two strains was 98.1%, but DNA-DNA hybridization indicated 44% relatedness. Strains BM5-7(T) and BM9-1(T) exhibited 16S rRNA gene sequence similarities of 98.0-99.2% and 97.7-98.1 %, respectively, with type strains of Martelella endophytica and Martelella mediterranea. Combined data from phenotypic, phylogenetic and DNA-DNA relatedness studies demonstrated that strains BM5-7(T) and BM9-1(T) are representatives of two novel species of the genus Martelella, for which the names Martelella radicis sp. nov. (type strain BM5-7(T)=DSM 28101(T)=LMG 27958(T)) and Martelella mangrovi sp. nov. (type strain BM9-1(T)=DSM 28102(T)=LMG 27959(T)) are proposed.