Pseudomonas aeruginosa capable of utilizing carboxin and oxycarboxin as sole sources of carbon and nitrogen was isolated from red sandy loam soil perfused with the solutions of these fungicides. The bacterium hydrolyzed oxycarboxin via the intermediate compound 2-(vinylsulphonyl) acetanilide liberating 2- (2-hydroxyethylsulphonyl) acetic acid and aminophenol, whereas carboxin was first oxidized to its sulphoxide and then to its sulphone before hydrolysis. Further hydrolysis of aminophenol by the organism resulted in the accumulation of ammonium which was partly oxidized to nitrite. Nitrite accumulated in the medium without further oxidation to nitrate.
