Bacterial reduction of fensulfothion and its hydrolysis product 4-methylsulfinyl phenol

Oxygen-limited cultures of Klebsiella pneumoniae reduced 4-methylsulfinyl phenol to 4-methylthiophenol. A study of the effect of 4-methylthiophenol on the growth of K. pneumoniae revealed that the specific growth rate was retarded by 40% in the presence of 200 micrograms of the phenol per ml. A soil bacterium, Hafnia sp., was isolated that could reduce the organophosphorus insecticide fensulfothion to fensulfothion sulfide.