Degradation of Chlorsulfuron by Soil Microorganisms

TLDR: In this paper, the degradation of chlorsulfuron was evaluated using plant bioassay and high-performance liquid chromatography (HPLC) radiotracer techniques.

Abstract: Degradation of chlorsulfuron {2-chloro-N- (((4- methoxy- 6- methyl-1,3 ,5 -triazin-yl)amino) carbonyl) benzene- sulfonamide} in acidic and alkaline soils was evaluated using plant bioassay and high-performance liquid chromatography (HPLC) radiotracer techniques. Soil sterilization with either ethylene oxide (EtO) or gamma irradiation significantly reduced breakdown of chlorsulfuron; the ability for degrada- tion was restored by reinoculation with indigenous soil micro- organisms. Streptomyces griseolus (a soil actinomycete), Aspergillus niger, and Penicillium sp. (soil fungi) were demon- strated to degrade 14C-chlorsulfuron in pure culture. In addition to microbial breakdown, chemical hydrolysis was an important factor in the disappearance of chlorsulfuron from soil. The contribution of chemical hydrolysis to total degradation was a function of soil pH, with hydrolysis oc- curring most rapidly in acidic soils. Both dissipation processes slowed markedly at low temperatures. Additional index words. Soil pH, soil temperature, soil mois- ture, Streptomyces griseolus, Aspergillus niger, Penicillium