CHRYSIOGENES-ARSENATIS GEN-NOV, SP-NOV, A NEW ARSENATE-RESPIRING BACTERIUM ISOLATED FROM GOLD MINE WASTE-WATER

A new strictly anaerobic bacterium (strain BAL-1(T)) has been isolated from a reed bed at Ballarat Goldfields in Australia, The organism gre w by reducing arsenate [As(V)] to arsenite [As(III)], using acetate as the electron donor and carbon source; acetate alone did not support g rowth, When BAL-1(T) was grown with arsenate as the terminal electron acceptor, acetate could be replaced by pyruvate, L- and D-lactate, suc cinate, malate, and fumarate hut not by H-2, formate, citrate, glutama te, other amino acids, sugars, or benzoate, When acetate was the elect ron donor, arsenate could be replaced by nitrate or nitrite but not by sulfate, thiosulfate, or iron oxide. Nitrate was reduced to ammonia v ia nitrite. The doubling time for growth on acetate (5 mM) plus arsena te (5 mM) or nitrate (5 mM) was 4 h, The G+C content of the DNA is 49 mol%, The 16S rRNA sequence data for the organism support the hypothes is that this organism is phylogenetically unique and at present is the first representative of a new deeply branching lineage of the Bacteri a, This organism is described as Chrysiogenes arsenatis gen. nov., sp, nov.