sp. nov., an acidotolerant sulphate-reducing bacterium isolated from moderately acidic fen soil.

An obligately anaerobic, spore-forming sulphate-reducing bacterium, strain SB140, was isolated from a long-term continuous enrichment culture that was inoculated with peat soil from an acidic fen. Cells were immotile, slightly curved rods that stained Gram-negative. The optimum temperature for growth was 28 °C. Strain SB140 grew at pH 4.0-7.5 with an optimum pH of 6.0-7.0 using various electron donors and electron acceptors. Yeast extract, sugars, alcohols and organic acids were used as electron donors for sulphate reduction. SB140 additionally used elemental sulphur and nitrate as electron acceptors but not sulphite, thiosulphate or iron(III) provided as ferrihydrite and fumarate. The 16S rRNA gene sequence placed strain SB140 in the genus of the phylum . The predominant cellular fatty acids were iso-C (52.6%) and 5,7 C (19.9%). The draft genome of SB140 (5.42 Mbp in size) shared 77.4% average nucleotide identity with the closest cultured relatives M1 and SJ4. On the basis of phenotypic, phylogenetic and genomic characteristics, SB140 was identified as a novel species within the genus , for which we propose the name sp. nov. The type strain is SB140 (=DSM 117342=JCM 39521).