Desulfoluna spongiiphila sp nov., a dehalogenating bacterium in the Desulfobacteraceae from the marine sponge Aplysina aerophoba

A reductively dehalogenating, strictly anaerobic, sulfate-reducing bacterium, designated strain AA1(T), was isolated from the marine sponge Aplysina aerophoba collected in the Mediterranean Sea and was characterized phenotypically and phylogenetically. Cells of strain AA1(T) were Gram-negative, short, curved rods. Growth of strain AA1(T) was observed between 20 and 37 degrees C (optimally at 28 degrees C) at pH 7-8. NaCl was required for growth; optimum growth occurred in the presence of 25 g NaCl l(-1). Growth occurred with lactate, propionate, pyruvate, succinate, benzoate, glucose and sodium citrate as electron donors and carbon sources and either sulfate or 2-bromophenol as electron acceptors, but not with acetate or butyrate. Strain AA1(T) was able to dehalogenate several different bromophenols, and 2- and 3-iodophenol, but not monochlorinated or fluorinated phenols. Lactate, pyruvate, fumarate and malate were not utilized without an electron acceptor. The G + C content of the genomic DNA was 58.5 mol%. The predominant cellular fatty acids were C-14:0, iso-C-14:0, C-14:0 3-OH, anteiso-C-15:0, C-16:0, C-16:0, C-16:1 omega 7c and C-18:1 omega 7c. Phylogenetic analysis based on 16S rRNA gene sequence comparisons placed the novel strain within the class Deltaproteobacteria. Strain AA1(T) was related most closely to the type strains of Desulfoluna butyratoxydans (96% 16S rRNA gene sequence similarity), Desulfofrigus oceanense (95%) and Desulfofrigus fragile (95%). Based on its phenotypic, physiological and phylogenetic characteristics, strain AA1(T) is considered to represent a novel species of the genus Desulfoluna, for which the name Desulfoluna spongiiphila sp. nov. is proposed. The type strain is AA1(T) (=DSM 17682(T) = ATCC BAA-1256(T)).