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

A novel anaerobic succinate-producing bacterium, strain ZWB(T), was isolated from sludge collected from a biogas desulfurization bioreactor (Eerbeek, the Netherlands). Cells were non-spore-forming, motile, slightly curved rods (0.4-0.5 mu m in diameter and 2-3 mu m in length), and stained Gram-negative. The temperature range for growth was 25-40 degrees C, with an optimum at 37 degrees C. The pH range for growth was 7.0-9.0, with an optimum at pH 7.5. Strain ZWB(T) was able to ferment glycerol and several carbohydrates mainly to H-2, succinate and acetate. Sulfur and fumarate could be used as electron acceptors by strain ZWB(T). The G+C content of the genomic DNA was 37.6 mol%. The most abundant fatty acids were iso-C-14:0 and iso-C-16:0 DMA. On the basis of 16S rRNA gene sequence similarity, strain ZWB(T) belongs to the family Ruminococcaceae and it is distantly related to Saccharofermentans acetigenes JCM 14006(T) (92.1 %). Based on the physiological features and phylogenetic analysis, strain ZWB(T) 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 ZWB(T) (=DSM 27333(T)=JCM 19283(T)).