Abstract: | A strictly anaerobic, homoacetogenic, Gram-positive, non spore-forming bacterium, designated strain SR12T(T=type strain), was isolated from an anaerobic methanogenic digestor fed with olive mill wastewater. Yeast extract was required for growth but could also be used as sole carbon and energy source. Strain SR12Tutilized a few carbohydrates (glucose, fructose and sucrose), organic compounds (lactate, crotonate, formate and betaine), alcohols (methanol), the methoxyl group of some methoxylated aromatic compounds, and H2+CO2. The end-products of carbohydrate fermentation were acetate, formate, butyrate, H2and CO2. End-products from lactate and methoxylated aromatic compounds were acetate and butyrate. Strain SR12Twas non-motile, formed aggregates, had a G+C content of 55 mol % and grew optimally at 35°C and pH 7.2 on a medium containing glucose. Phylogenetically, strain SR12Twas related toEubacterium barkeri, E. callanderi, andE. limosumwithE. barkerias the closest relative (similarity of 98%) with which it bears little phenotypic similarity or DNA homology (60%). On the basis of its phenotypic, genotypic, and phylogenetic characteristics, we propose to designate strain SR12TasEubacterium aggreganssp. nov. The type strain is SR12T(=DSM 12183). |