International audienceA novel anaerobic, alkaliphilic, mesophilic, Gram-stain-positive, endospore-forming bacterium was isolated from an alkaline thermal spring (42 °C, pH 9.0) in New Caledonia. This bacterium, designated strain LB2 T , grew at 25–50 °C (optimum, 37 °C) and pH 8.2–10.8 (optimum, pH 9.5). Added NaCl was not required for growth (optimum, 0–1 %) but was tolerated up to 7 %. Strain LB2 T utilized a limited range of substrates, such as peptone, pyruvate, yeast extract and xylose. End products detected from pyruvate fermentation were acetate and formate. Both ferric citrate and thiosulfate were used as electron acceptors. Elemental sulphur, nitrate, nitrite, fumarate, sulphate, sulfite and DMSO were not used as terminal electron ...