BIODEGRADATION OF SOME PESTICIDES BY SOIL MICROORGANISMS

Abstract

It is well known that organophosphorus pesticides are widely used in Egyptian agriculture for pests control such as insects, nematodes and weeds which attack different crops. These pesticides cause environmental problems.

In view of vital role of some microorganisms m degradation and detoxification of pesticides, it is necessary to study;. t e local isolates which active in degradation of organophosphorus pesticides such as (diazinon and nemacur) which were chosen to carry out this study.

For this purpose, a series of laboratory and pot experiments were designed and carried out. Obtained results . can be summarized in the following

5.1. Isolation of degrading diazinon microorganisms from soil.

Soil enrichment technique was used to isolate the microorganisms able to degrade diazinon.

In this experiment soil samples were treated with diazinon increasingly at a concentration of 50 ppm. Treated soil samples were incubated under the laboratory temperature for.75 days.

Obtained data showed that microbial densities and CO2 evolution were gradually decreased with the increase of incubation period. At 75 days of incubation period,