Abstract:

In order to obtain the best organophosphorus pesticide-degrading bacterium at low cost, we use sweet potato starch wastewater to ferment inocula, which can decrease the COD of wastewater and lessen environment pollution. In this study, the organophosphorus pesticide-degrading bacterium strain N20 was isolated from Brassica napus leaf. The strain N20 was preliminarily identified as Bacillus cereus using scanning electron microscopic observations, 16S rDNA sequence homology comparison and phylogenetic analysis. Furthermore, the potato starch wastewater was used as the culture media to explore the influence of growth status in different culture conditions. The results of research showed that the optimum culture condition determined with shaking flask cultures was at the bacterium spawn age of 10 hours, inoculation capacity 5%, initial pH 7.0-7.5, shaking speed 200 r/min, temperature 35℃, and fermentation time 24 hours. These results were the available parameters for the industrial production of this organophosphorus pesticide-degrading agent.