Isolation and Characterization of Carbendazim-degrading Rhodococcus erythropolis djl-11

PLoS One

Hongmei Li¹  Xinjian Zhang²  Yujie Huang²  Jianing Wang²  Jishun Li²  Paul R. Harvey²  Hetong Yang²  Yan Ren² 

[1] CSIRO Sustainable Agriculture National Research Flagship and CSIRO Ecosystem Sciences, Glen Osmond, South Australia, Australia;Shandong Provincial Key Laboratory of Applied Microbiology, Biotechnology Center of Shandong Academy of Sciences, Jinan, Shandong Province, People's Republic of China

关键词: Biodegradation;    Esterases;    Fungicides;    Rhodococcus;    Agricultural soil science;    Polymerase chain reaction;    Liquid chromatography-mass spectrometry;    Pseudomonas;   

DOI  :  10.1371/journal.pone.0074810

学科分类：医学（综合）

来源: Public Library of Science

【 摘 要 】

Carbendazim (methyl 1H-benzimidazol-2-yl carbamate) is one of the most widely used fungicides in agriculture worldwide, but has been reported to have adverse effects on animal health and ecosystem function. A highly efficient carbendazim-degrading bacterium (strain dj1-11) was isolated from carbendazim-contaminated soil samples via enrichment culture. Strain dj1-11 was identified as Rhodococcus erythropolis based on morphological, physiological and biochemical characters, including sequence analysis of the 16S rRNA gene. In vitro degradation of carbendazim (1000 mg·L−1) by dj1-11 in minimal salts medium (MSM) was highly efficient, and with an average degradation rate of 333.33 mg·L−1·d−1 at 28°C. The optimal temperature range for carbendazim degradation by dj1-11 in MSM was 25–30°C. Whilst strain dj1-11 was capable of metabolizing cabendazim as the sole source of carbon and nitrogen, degradation was significantly (P<0.05) increased by addition of 12.5 mM NH4NO3. Changes in MSM pH (4–9), substitution of NH4NO3 with organic substrates as N and C sources or replacing Mg2+ with Mn2+, Zn2+ or Fe2+ did not significantly affect carbendazim degradation by dj1-11. During the degradation process, liquid chromatography-mass spectrometry (LC-MS) detected the metabolites 2-aminobenzimidazole and 2-hydroxybenzimidazole. A putative carbendazim-hydrolyzing esterase gene was cloned from chromosomal DNA of djl-11 and showed 99% sequence homology to the mheI carbendazim-hydrolyzing esterase gene from Nocardioides sp. SG-4G.

【 授权许可】

CC BY