BIODEGRADATION OF PIRIMIPHOS-METHYL USING TWO TYPES OF MICROORGANISMS ISOLATED FROM FAYOUM GOVERNORATE SOIL

Document Type : Research articles.

Authors

Plant Protection Dept., Fac. of Agric., Cairo Univ., Fayoum Branch, Egypt.

Abstract

The results showed that the half-life of the pirimiphos-methyl
ranged between 2.1 and 1.57 day in non- sterilized soil under 27˚C and
moisture content 25 and 50% respectively. Also, at the same
temperature degree in sterilized soil the half- life of the pirimiphosmethyl reached about 30.1 and 3.8 day under moisture content 25 and
50% respectively. The half- life of pirimiphos- methyl soil under 35˚C
was about 2 and 1.8 day in non- sterilized soil for both tested moisture
content 25 and 50% respectively. In sterilized soil, the half-life of the
same insecticide under 35˚C was about 6.01 and 3.5 day for 25 and 50%
moisture content, respectively.
Two strains of microorganisms were isolated from the soil one of
them a positive gram bacteria strain and the other is a fungi strain. The
breakdown of pirimiphos– methyl through these organisms was
investigated in a liquid media. The degradation rate of pirimiphosmethyl was faster after first, second and third day by the fungi than the
bacteria strain under 35˚C incubation temperature. On the other hand the
degradation by bacteria was accelerated up to the fourth day of
incubation. These effects may be due to the increase of the extracellular
esterase activity, which tend to increase from the second day of
incubation period. Generally, the degradation of pirimiphos-methyl by
the two tested microorganisms was higher under 35˚C than 27˚C. The
glucose consumption by the bacteria strain seemed to be correlated to
the increase in the esterase activity up to the third day of incubation
period. No significant differences were found between the control and
the fungi in its glucose consumption.

Keywords

Files

Share

How to cite

Statistics