title: Bioremediation of chlorimuron-ethyl-contaminated soil by Hansschlegelia sp. strain CHL1 and the changes of indigenous microbial population and N-cycling function genes during the bioremediation process.
abstract: Long-term and excessive application of the herbicide chlorimuron-ethyl has led to soil degradation and crop rotation barriers. In the current study, we isolated bacterial strain Hansschlegelia sp. CHL1, which can utilize chlorimuron-ethyl as its sole carbon and energy source, and investigated its application in soil bioremediation. Indigenous microbial populations and N-cycling function in the soil were also investigated during the bioremediation process by monitoring the copy numbers of bacterial and fungal marker genes, as well as N-cycling functional genes (nifH, amoA, nirS, and nirK). Results showed that >95% of chlorimuron-ethyl could be degraded within 45 days in soils inoculated with CHL1. Inoculation at two time points resulted in a higher remediation efficiency and longer survival time than a single inoculation. At the end of the 60-day incubation, the copy numbers of most indicator genes were recovered to the level of the control, even in the single-inoculation soils. A double inoculation was necessary for recovery of nifH. However, the abundance of nirK and ammonia-oxidizing bacterial genes were significantly inhibited regardless of inoculum. The results suggested that CHL1 is effective for the remediation of chlorimuron-ethyl-contaminated soil, and could partially reduce the toxic effects of chlorimuron-ethyl on soil microorganisms.
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Liqiang
authors.initials: L
authors.lastname: Yang
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Li
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Li
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.
authors.forename: Zhencheng
authors.initials: Z
authors.lastname: Su
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.
authors.forename: Chenggang
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China. Electronic address: hwzhang@iae.ac.cn.
authors.forename: Huiwen
authors.initials: H
authors.lastname: Zhang
mesh_terms: D001673:Biodegradation, Environmental; D005798:Genes, Bacterial; D005800:Genes, Fungal; D006540:Herbicides / Q000378:metabolism*; D042083:Methylocystaceae / Q000235:genetics / Q000378:metabolism*; D058458:Nitrogen Cycle; D011743:Pyrimidines / Q000378:metabolism*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013453:Sulfonylurea Compounds / Q000378:metabolism*
chemical_list: D006540:Herbicides; D011743:Pyrimidines; D012989:Soil Pollutants; D013453:Sulfonylurea Compounds; C112343:chlorimuron ethyl
keywords: Bioremediation; Chlorimuron-ethyl; Hansschlegelia sp; N-cycling functional gene