Degradation of nicosulfuron by Bacillus subtilis YB1 and Aspergillus niger YF1

作者:Lu X H*; Kang Z H; Tao B; Wang Y N; Dong J G; Zhang J L
来源:Applied Biochemistry and Microbiology, 2012, 48(5): 460-466.
DOI:10.1134/S0003683812050079

摘要

The optimal degrading conditions for the nicosulfuron degradation by Bacillus subtilis YB1 and Aspergillus niger YF1, and site of their action on nicosulfuron were studied. The results showed that the degradation efficiency of free cells of B. subtilis YB1 and A. niger YF1 was respectively 87.9 and 98.8% in basic medium III containing 2 mg/l of nicosulfuron after inoculation with 1 ml of culture containing 2.3 x 10(7) CFU ml(-1) and incubation for 5 days at 35A degrees C. Moreover, the degradation rate of nicosulfuron by the mixture of microorganisms was much higher than for every of them taken separately in the same conditions. The mass spectrometric analysis of the products degraded by B. subtilis YB1 revealed that the sulfonylurea bridge in nicosulfuron molecule had been broken. Extracellular (EXF) and endocellular (ENF) fractions obtained from bacterium and fungus were tested for the ability to degrade nicosulfuron. The degradation efficiency of fractions extracted from B. subtilis YB1 was 66.8% by EXF and 15.8% by ENF, but neither EXF nor ENF extracted from A. niger YF1 had the activity of degrading nicosulfuron.

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