Genomic basis for pesticide degradation revealed by selection, isolation and characterisation of a library of metaldehyde-degrading strains from soil
Genomic basis for pesticide degradation revealed by selection, isolation and characterisation of a library of metaldehyde-degrading strains from soil
复制标题
DOI：
10.1016/j.soilbio.2019.107702
复制
发表时间：
2020-03-01
影响因子：
9.7
通讯作者：
Moir, James W. B.
中科院分区：
文献类型：
--
作者：
Castro-Gutierrez, Victor;Fuller, Edward;Moir, James W. B.
三聚乙醛是一种异生环醚，在农业和园艺中被用作杀螺剂的选择，但最近在饮用水源中检测到它已成为一个令人关注的主要原因。我们从分配和农业土壤中分离出8种新的四聚乙醛降解细菌菌株，并确定了一个高度保守的基因簇，该基因簇在一个伽马和五个β-变形菌之间共享，并且没有密切相关的非降解型菌株。化学诱变和异源表达。大肠杆菌中，证实该基因簇负责四聚乙醛的降解。其他缺乏这种途径的四聚乙醛降解分离株表明，已经进化出多种降解机制。我们证明了在多种土壤中四聚乙醛的加速生物降解，突出了自然界中四聚乙醛降解中生物组分的重要性。我们证实，在土壤中的四聚乙醛降解人口增殖响应四聚乙醛，但没有大的变化，作为一个整体的社会组成的检测，表明该过程是由一些罕见的类群。在这里，我们确定了土壤中四聚乙醛生物降解的第一个遗传决定因素，为有针对性的生物修复策略铺平了道路。
Metaldehyde, a xenobiotic cyclic ether, is used as molluscicide of choice in agriculture and horticulture, but recently its detection in drinking water sources has become a major cause of concern. We isolated eight new metaldehyde-degrading bacterial strains from allotment and agricultural soils and identified a highly-conserved gene cluster shared amongst one gamma and five beta-proteobacteria, and absent from closely-related, non-degrading type strains. Chemical mutagenesis, and heterologous expression in E. coli, confirmed that this gene cluster is responsible for metaldehyde degradation. Other metaldehyde-degrading isolates that lack this pathway indicate that multiple degradation mechanisms have evolved. We demonstrated accelerated biodegradation of metaldehyde in multiple soils, highlighting the importance of the biological component in metaldehyde degradation in nature. We confirmed that the metaldehyde-degrading population in soil is proliferating in response to metaldehyde, but no bulk changes in the composition of the community as a whole were detected, indicating the process is governed by a few rare taxa. Here, we identified the first genetic determinants for the biological degradation of metaldehyde in soil paving the way for targeted bioremediation strategies.