Desulfotomaculum ferrireducens sp. nov., a moderately thermophilic sulfate-reducing and dissimilatory Fe(III)-reducing bacterium isolated from compost

A novel dissimilatory Fe(III)-reducing bacterium, designated strain GSS09T, was isolated from a compost sample by using a solid medium containing acetate and ferrihydrite as electron donor and electron acceptor, respectively. Cells of strain GSS09T were anaerobic, Gram-stain-positive, motile, endospore-forming and rod-shaped. Growth occurred at 30-55 °C (optimum 50 °C), at pH 6.5-9.0 (optimum pH 7.5) and in the presence of 0-3 % (w/v) NaCl (optimum 1 %). Both sulfur compounds such as sulfate, sulfite and thiosulfate and Fe(III) oxides such as ferrihydrite could be utilized as electron acceptors. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GSS09T was related closely to Desulfotomaculum hydrothermale Lam5T (94.5 % sequence similarity). The major fatty acids were C16 : 0 and C16 : 1ω7c/C16 : 1ω6c. The G+C content of the genomic DNA was 49.1 mol%. On the basis of phylogenetic analysis, phenotypic characterization and physiological tests, strain GSS09T is considered to represent a novel species of the genus Desulfotomaculum, for which the name Desulfotomaculum ferrireducens sp. nov. is proposed. The type strain is GSS09T (=KCTC 15523T=MCCC 1K01254T).