The Drilosphere as a Driver of Microbial Metabolism of Herbicides in Soil: Linking Processes with Populations

钻圈作为土壤中除草剂微生物代谢的驱动力：将过程与种群联系起来

• 批准号: 41017971
• 负责人: Professor Dr. Marcus A. Horn
• 金额: --
• 依托单位: Institut für Mikrobiologie (ifmb)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/41017971?language=en
• 关键词: Drilosphere; Driver; Microbial; Metabolism; Herbicides

Herbicides are widely used in agriculture. Degradation of phenoxyalkanoic acid (PAA) herbicides and their derivatives is catalyzed in the drilosphere (i.e., earthworm gut content, cast, and burrows). Burrow walls represent interfaces in soil with up to 1.2 m2 m-3 and are ‘hotspots’ for the aerobic degradation of PAA herbicides. Earthworm eco-types (i.e., epigeic, anecic, or endogeic species) might impact on the intensity of burrow formation and thus herbicide degradation. However, the effect of earthworm eco-type on herbicide degradation is unknown. Degradation pathways of many herbicides, associated structural genes, and associated organisms in the drilosphere, are poorly resolved. Based on these deficiencies of information, the following hypotheses will be tested: (i) the drilosphere harbors hitherto unknown, highly active prokaryotes that transform the herbicide bentazon and (ii) the earthworm eco-type impacts on PAA, 2,4-dichlorophenol, and bentazon degradation. Degradation intermediates and products will be determined by high performance liquid chromatography and scintillation counting. Subtractive transcriptome analysis and 454 pyrosequencing will identify structural genes involved in herbicide degradation. 16S rRNA stable isotope probing, quantitative structural gene-targeted PCR, most probable number analyses, and isolation approaches will be utilized to identify and characterize process-associated microbial populations.

除草剂在农业中被广泛使用。苯氧基烷酸(PAA)除草剂及其衍生物的降解是在旱层(即蚯蚓肠道内容物、铸模和洞穴)中催化的。洞壁代表面积达1.2平方米m-3的土壤中的界面，是PAA除草剂好氧降解的“热点”。蚯蚓生态类型(即表生、变态或内生种)可能会影响洞穴形成的强度，从而影响除草剂的降解。然而，蚯蚓生态型对除草剂降解的影响尚不清楚。许多除草剂、相关的结构基因和相关生物在干旱圈中的降解途径没有得到很好的解决。基于这些信息的不足，将检验以下假设：(I)钻井圈含有迄今未知的、高度活跃的原核生物，它们转化除草剂苯达松；(Ii)蚯蚓生态类型对PAA、2，4-二氯苯酚和苯达松降解的影响。降解中间体和降解产物将通过高效液相色谱和闪烁计数进行测定。消减转录组分析和454焦磷酸测序将确定与除草剂降解有关的结构基因。将利用16S rRNA稳定同位素探测、定量结构基因靶向聚合酶链式反应、最可能数分析和分离方法来识别和表征与过程相关的微生物种群。