Biodegradation of Malathionby Pseudomonas Spp. and Bacillus Spp. Isolated Frompolluted Sites in Egypt

Malathion is a widely used organophosphate pesticide as it is applied to control a wide range of sucking and chewing pest of field crops, fruits and vegetables. The present study reports the isolation of malathion-degrading bacteria using enrichment technique. Morphological, biochemical and 16S rRNA identification was carried out. The analysis showed that one of the isolated bacteria was belonging to Bacillus genusand the other was assigned Pseudomonas aeruginosa. The two malathion-degrading isolates were grown in Minimal Salt Medium (MSM) containing different concentration of Malathion (6841 ppm, 14253 ppm, 28506 ppm and 42759 ppm). Malathion residues (degradation products) were measured with Gas Chromatography/Mass Spectrometry after 7 days of incubation at 35°C with the isolated strains in parallel with control samples. Results indicate that Pseudomonas aeruginosa and Bacillus spp. were able to utilize malathion a sole carbon and energy source even at high concentration and to degrade it co-metabolically. The study revealed that soil bacterial isolates can be used in bioremediation of environmental pollution caused by malathion.