Bacterial Oxidation of Arsenite

Abstract

IN 1918 H. H. Green¹ isolated from arsenical cattle-dipping fluids in South Africa a bacterium, provisionally referred to as Bacillus arsenoxydans but since lost², which was able to grow in culture media cantaining up to 1 per cent of As₂O₃ as arsenite and to bring about its oxidation to arsenate. In view of the well-known toxicity of tervalent arsenicals, now largely explicable in terms of their inhibitory action upon highly important sulphydryl-dependent metabolic enzymes^3'4, it is particularly unfortunate that Green's valuable paper, being published in an annual report mainly devoted to veterinary research, apparently escaped the attention of enzymologists and general bacteriologists ; for the enzymic mechanism of arsenite oxidation was never studied while the strain was available, nor was the existence of arsenite-oxidizing bacteria ever afterwards reported.