Anaeroselena agilis gen. nov., sp. nov., a Novel Sulfite- and Arsenate-Respiring Bacterium Within the Family Acetonemataceae Isolated from a Thermal Spring of North Ossetia.

A novel Gram-negative, motile, rod-shaped bacterium, designated 4137-cl, was isolated from a thermal spring of North Ossetia (Russian Federation). Strain 4137-cl grew at 30-50 °C (optimum 42 °C) with 0-3.5% NaCl (optimum 0-0.3%) and within pH range 4.0-8.7 (optimum pH 6.8-7.3). It was a strictly anaerobic microorganism capable of fermentation and respiration on organic acids and proteinaceous substrates. Sulfur, sulfite, polysulfide, and arsenate were used as electron acceptors. In addition to heterotrophic growth it grew autotrophically with H/CO. The major fatty acids were C ω8c and C. The size of the genome and genomic DNA G+C content of strain 4137-cl were 4.5 Mb and 59.2%, respectively. According to the 16S rRNA gene sequence and conserved protein sequences phylogenies, strain 4137-cl represented a distinct lineage of the family Acetonemataceae within the class Negativicutes. As inferred from the morphology, physiology, chemotaxonomical and phylogenomic analyses, strain 4137-cl ought to be recognized as a novel genus for which the name Anaeroselena agilis gen. nov., sp. nov., we propose. The type strain is 4137-cl(=KCTC 25383 = VKM B-3575).