Amorphus coralli gen. nov., sp. nov., a marine bacterium isolated from coral mucus, belonging to the order Rhizobiales

A bacterial strain, designated RS.Sph.026^T, was isolated from mucus of the coral Fungia granulosa collected from the northern Red Sea (Gulf of Eilat, Israel). The bacterium was found to be Gram-negative, non-motile, halotolerant and heterotrophic. Comparative 16S rRNA gene sequence analyses showed that strain RS.Sph.026^T belonged to the order Rhizobiales, with the highest levels of 16S RNA gene sequence similarity with Rhodobium orientis (92 %). Strain RS.Sph.026^T grew optimally at a salinity of 3-4 %, pH 7.5-8 and 25-30 6C. The major cellular fatty acids were cis-7-octadecenoic acid (C₁₈ : ₁ω7c; 57.2 %) and C₁₉ : ₀ cyclo ω8c (15.5 %). The DNA G+C content of strain RS.Sph.026^T was 67.1 mol%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain RS.Sph.026^T represents a novel genus and species in the order Rhizobiales, for which the name Amorphus coralli gen. nov., sp. nov. is proposed. The type strain is RS.Sph.026^T (=LMG 24307^T=DSM 19760^T).