Ercella succinigenes gen. nov., sp nov., an anaerobic succinate-producing bacterium

A novel anaerobic succinate-producing bacterium, strain ZWBT, was isolated from sludge collected from a biogas desulfurization bioreactor (Eerbeek, The Netherlands). Cells were non-spore forming, motile, slightly curved rods (0.4 to 0.5 µm in diameter and 2 to 3 µm in length), and stained Gram-negative. The temperature range for growth was 25 to 40°C, with an optimum at 37°C. The pH range for growth was 7.0 to 9.0, with an optimum at pH 7.5. Strain ZWBT ferments glycerol and several carbohydrates to mainly H2, succinate, and acetate. Sulfur and fumarate could be used as electron acceptors by strain ZWBT. The G+C content of the genomic DNA was 37.6 mol%. The most abundant fatty acids were iso-C14:0 (28.3%), an iso-C16:0 DMA (27.0%). On the basis of 16S rRNA gene sequence similarity, strain ZWBT belongs to the Ruminococcaceae family and it is distantly related to Saccharofermentans acetigenes (92.1% sequence similarity of the rRNA genes). Based on the physiological features and phylogenetic analysis, strain ZWBT represents a novel species of a new genus, for which the name Ercella succinigenes gen. nov., sp. nov. is proposed. The type strain of Ercella succinigenes is ZWBT (=DSM 27333T =JCM 19283T).