[Production, partial purification and characterization of methamidophos-degrading enzyme from methylotroph WB-1]

After cultivation for 20 h in the inorganic salt medium with methamidophos as sole carbon and nitrogen source, Methylotroph WB-1 could produce methamidophos-degrading enzyme in larger amounts. The enzyme was partially purified by sonication disruption, Tween-20 extraction, heat treatment(9 min at 60 degrees C), DEAE-cellulose 32 and CM-cellulose32 chromatography with 22.8 times purification and 78.8% recovery. Activity staining showed single violate band corresponding to that of protein staining. Optimum pH of the enzyme was 9.0; poor substrate specificity was showed. It was strongly inhibited by Hg2+, Mn2+ and Cu2+, but not by Co2+ and Zn2+; it also exhibited poor stability.