Abstrakt

Aerobic degradation of buprofezin via novel degradation intermediates by Rhodococcus sp. strain RX-3

Renxue Li, Chun Dai, Guangli Wang, Shaoxian Wu, Yubao Gong, Yuanyuan Jiang, Zhijia Wang, Naiyue Sun

Buprofezin is a commonly used chemical with satisfactory efficacy against sucking insect pests, but its disposal causes serious environmental problems. In this study, a bacterial strain RX-3 isolated by continuous enrichment from buprofezin-treated soil was tested for biodegradation of buprofezin. The bacteria were most similar to Rhodococcus sp. based on their morphological, physiological and biochemical characteristics, as well as phylogenetic placement inferred from 16S rRNA gene sequence. Strain RX-3 was found capable of utilizing buprofezin as the sole source of carbon for growth over a wide range of temperature (25-45°C) and pH (5.0-9.0) conditions. It could completely degrade 60 mg/L of buprofezin within 80 h, and in the presence of metals such as Ba2+, Zn2+ and Cu2+. In addition, six newly identified metabolites formed during buprofezin degradation were detected and identified by gas chromatography-mass spectrometry (GC-MS), from which we proposed a novel degradation pathway. Our results suggest that Rhodococcus sp. RX-3 could be a potential bioremediation agent of buprofezin-contaminated environments.