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

Abstract

Two Gram-stain-negative, non-motile, rod-shaped bacterial strains, designated BM5-7T and BM9-1T 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 C19 : 0 cyclo ω8c and C18 : 1ω7c as the major cellular fatty acids and Q-10 as the dominant ubiquinone. The genomic DNA G+C contents of strains BM5-7T and BM9-1T 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 BM5-7T and BM9-1T 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 BM5-7T and BM9-1T are representatives of two novel species of the genus Martelella , for which the names Martelella radicis sp. nov. (type strain BM5-7T = DSM 28101T = LMG 27958T) and Martelella mangrovi sp. nov. (type strain BM9-1T = DSM 28102T = LMG 27959T) are proposed.