[Biodegradation of herbicide pendimethalin by fungi and its characteristics]

Fungi, which can grow on and degrade pendimethalin, were isolated from activated sludge and soil. The biodegradation characterization in vitro was studied. The results showed that pendimethalin could be degraded by fungi, 16 fungi were isolated by enrichment culture, among which, 10 fungi could degrade more than 60% pendimethalin in 5 days in culture fluid. According to the physiological resistance and the capacity to degrade pendimethalin, three fungi were considered as efficiently degrading strains identified as Aspergillus terreus, Monilochaetes and Aspergillus furnigatus. The efficiency of degradation was affected by culture conditions such as pH, temperature, and concentration of cane sugar and pendimethanlin. The results showed that when the additional carbon source was 0.5%-1.0%, pH value was 6-8, and cultivated temperature was 20-30 degrees C, the growth amount of fungi and the degradation rate were enhanced. The fungi grew quickly, and the biodegradation rate was high under pendimethalin concentration being 100 mg.L-1. The removed amount of pendimethalin increased with increasing pendimethalin concentration. The optimal conditions were proposed, which could provide theoretic basis for prevention and control of pesticides pollution.