Microbial degradative activity in pesticide pretreated soil

Abstract

A pesticide disposal site was identified which had been exposed to various pesticides for several years. The degradative activity of this soil was assessed using several herbicides and a marker compound, 4‐chlorophenol. The phenol was converted to CO₂ and other polar products within 157 days in culture. Propanil (3,4‐dichloropropionanilide) was converted to 3,4‐dichloroaniline. Diuron [N'‐(3,4‐dichlorophenyl)‐N,N‐dimethylurea] and Trifluralin [2,6‐dinitro‐N,N‐dipropyl‐4‐(trifluoromethyl) benzenamine] were not degraded over the time period studied. In liquid cultures with a soil inoculum, propanil was completely degraded in 155 hours. These studies showed that the soil from the disposal site was active in degrading several different types of chemicals and may serve as a source for the isolation of degraders.

Key words:

• diuron
• propanil
• trifluralin
• chlorophenol
• microbial degradation
• soil