PURIFICATION AND CHARACTERIZATION OF CARBARYL HYDROLASE FROM BLASTOBACTER SP STRAIN-M501

A bacterium capable of hydrolyzing carbaryl (1-naphthyl-N-methylcarbam ate) was isolated from a soil enrichment. This bacterium was character ized taxonomically as a Blastobacter sp. and designated strain M501. A carbaryl hydrolase present in this strain was purified to homogeneity by protamine sulfate treatment, ammonium sulfate precipitation, and h ydrophobic, anion-exchange, gel filtration, and hydroxylapatite chroma tographies. The native enzyme had a molecular mass of 166,000 Da and w as composed of two subunits with molecular masses of 84,000 Da. The op timum pH and temperature of the enzyme activity were 9.0 and 45-degree s-C, respectively. The enzyme was not stable at temperatures above 40- degrees-C. The purified enzyme hydrolyzed seven N-methylcarbamate inse cticides and also exhibited activity against 1-naphthyl acetate and 4- nitrophenyl acetate.