Aminomonas paucivorans gen. nov., sp. nov., a mesophilic, anaerobic, amino-acid-utilizing bacterium

摘要

\ud\udA novel, asaccharolytic, amino-acid-degrading bacterium, designated strain GLU-3, was isolated from an anaerobic lagoon of a dairy wastewater treatment plant. Strain GLU-3 stained Gram-negative and was an obligately anaerobic, non-spore-forming, slightly curved, rod-shaped bacterium (0·3 × 4·0–6·0 μm) which existed singly or in pairs. The DNA G+C content was 43 mol%. Optimum growth occurred at 35 °C and pH 7·5 on arginine with a generation time of 16 h. Good growth was obtained on arginine, histidine, threonine and glycine. Acetate was the end-product formed from all these substrates, but in addition, a trace of formate was detected from arginine and histidine, and ornithine was produced from arginine. Strain GLU-3 grew slowly on glutamate and produced acetate, carbon dioxide, formate, hydrogen and traces of propionate as the end-products. In syntrophic association with , strain GLU-3 oxidized arginine, histidine and glutamate to give propionate as the major product; acetate, carbon dioxide and methane were also produced. Strain GLU-3 did not degrade alanine and the branched-chain amino acids valine, leucine and isoleucine either in pure culture or in association with . The nearest phylogenetic relative of strain GLU-3 was the thermophile (similarity value of 89·5%). As strain GLU-3 is phylogenetically, physiologically and genotypically different from other amino-acid-degrading genera, it is proposed that it should be designated a new species of a new genus gen. nov., sp. nov. (DSM 12260).