Abstract:

The aim was to isolate and screen the high-efficiency and broad-spectrum biodegradating fungis from the contaminated soil to a high concentration of omethoate, and studied the degradation characterizations. In this study, high-efficiency organophosphorus-degrading fungis were selected through domestication, separation, screening process. They were preliminaryly identified by a series of fungi colony morphological, physiological characteristics and 18s rDNA sequences and other tests. The effects of external factors such as initial pH, culture temperature, initial omethoate concentration on growth and omethoate-degradation of strains were studied. Two strains J4 and J6 were screened and identified as Aspergillus niger. Under the conditions of culture time 5 days, initial omethoate concentration 1000 mg/L, initial pH 6.0 and 6.5 respectively, temperature 30℃ and 28℃, shaking speed 160 r/min, the strains could grow best and have the highest biodegradation rates of 77.83% and 70.81%. And the growth of the strains related positively to the biodegradation rate of omethoate. And it should also be noted that Aspergillus J4 and J6 still had characteristic of broad-spectrum degradation organophosphorus pesticides.