Oxidation of Arsenite by a Soil Isolate ofAlcaligenes

摘要

A strain ofAlcaligenes, isolated from soil and grown in nutrient broth in the presence of arsenite, possessed the ability to oxidize arsenite to arsenate. Washed cell suspensions consumed one‐half mol of oxygen/mol of arsenite and produced arsenate. The optimum pH for arsenite oxidation was 7.0. TheKmfor arsenite was 1.5 × 10‐4M andVmaxwas 6.7 μl of oxygen/min. The arsenite‐oxidizing enzyme system was induced by growth in arsenite. Response of the arsenite‐oxidizing enzyme system to respiratory inhibitors suggested that electrons resulting from arsenite oxidation by an oxido‐reductase with a bound flavin are transferredviacytochromecand cytochrome oxidase to oxygen. The presence of the cytochromes in crude extract was confirmed by spectral m