Influence of microbial and enzymatic activities on immobilisation of xenobiotics in soil organo-clay complexes

微生物和酶活性对土壤有机粘土复合物中外源物质固定的影响

• 批准号: 40956283
• 负责人: Professor Dr. Jan Schwarzbauer
• 金额: --
• 依托单位: Lehrstuhl für Organische Biogeochemie in Geo-Systemen (OBG)
• 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 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/40956283?language=en
• 关键词: Influence; microbial; enzymatic; activities; immobilisation

Organo-clay complexes are a major sink of non-extractable residues in soil. Although it is known that this incorporation is dominantly assisted by microbial activity, the exact mechanism remains unclear. The competition of extracellular enzyme activity versus contribution of living biomass is under discussion. Therefore we will study the role and participation of microorganisms as well as stabilized extracellular enzymes in the covalent immobilization process of two xenobiotics on organo-clay particles in soil, i.e. the endocrine disrupting compound 353-nonylphenol (p-353-NP) and the fungicide metalaxyl.Three systems are investigated: (a) whole soil, (b) native organo-clay complexes and (c) model organo-clay complexes, both in sterilized and non-sterilized form. This strategy will allow the separation of effects from living micororganisms from those of extracellular enzymes and enables the detailed characterisation of microbial assisted bonding processes. NER formation will be followed by radioanalyses using 14C-xenobiotics and quantitative, enantioselective as well as compound specific isotope analyses using unlabelled substances. Further on the potential of specific enzymes (peroxidase, phenoloxidase) for NER formation will be tested.We will thus test the hypothesis that extracellular enzyme activities are the main driving force for covalent immobilization of xenobiotics to organo-clay complexes in soils.

有机粘土络合物是土壤中不可提取残留物的主要储存库。虽然已知这种结合主要是由微生物活动辅助的，但确切的机制尚不清楚。讨论了胞外酶活性与生物量贡献的竞争。因此，我们将研究微生物和稳定的胞外酶在土壤有机粘土颗粒上的共价固定过程中的作用和参与，即内分泌干扰化合物353-壬基酚（p-353-NP）和杀菌剂甲霉酯。研究了三种系统：(a)全土壤，(b)天然有机粘土复合物和(c)模型有机粘土复合物，包括灭菌和非灭菌形式。这一策略将允许从活微生物的细胞外酶的效果分离，并使微生物辅助键合过程的详细表征。在NER形成之后，将使用14c异种生物制剂进行放射性分析，并使用未标记物质进行定量、对映选择性和化合物特异性同位素分析。将进一步测试特定酶（过氧化物酶、酚氧化酶）对NER形成的潜力。因此，我们将检验细胞外酶活性是异种生物共价固定在土壤有机粘土复合体上的主要驱动力这一假设。