Isolation and Characterization of Three Bacterium Strains for Biodegradation of Methamidophos

Abstract

In this study, three bacterium strains capable of degrading methamidophos (MAP) were isolated from the soil samples contaminated with organophosphorus pesticides (OPs). According to morphological characteristics, physiological properties, and 16S rDNA sequence analysis, the isolates HS-A32, HS-D36, and HS-D38 were identified as Acinetobacter sp., Pseudomonas stutzeri and Pseudomonas aeruginosa, respectively. They could utilize MAP as the sole carbon and nitrogen source, and the degradation ratio upon 500 mg/L MAP could reach 80% in 3 days under optimal conditions (pH 7.0, 30-35 °C). The strains could use glucose, fructose, ethanol, and galactose as carbon and energy sources, and the favorable nitrogen source included organic and inorganic nitrogen. Further studies showed that the three strains could degrade various OPs. The characterized strains with broad-spectrum OP-degrading activities could be useful for the biodegradation of MAP and the other OPs.