The detritusphere as the biogeochemical interface for bacterial and fungal degradation of MCPA

碎屑层是研究除草剂MCPA降解过程中微生物-物理化学相互作用的极好模型。鉴于在SPP 1315的第一阶段，我们专注于土壤凋落物界面的细菌和真菌丰度以及不同隔室之间的碳流，第二阶段将致力于阐明MCPA在碎屑层中降解的复杂调节机制：(1)在细胞水平上，共底物可获得性和漆酶丰度可能是重要的调节因素；(2)在群落水平上，携带不同类别TFDA基因的细菌可能控制MCPA的降解；(3)在微生境水平上，MCPA降解者与有机矿物表面的相互作用以及运输过程可能是重要的调节因素。在对土壤-凋落物界面附近的小规模微生物生长、MCPA迁移和MCPA降解进行模拟时，将纳入对MCPA降解进行分级管理的概念。

The detritusphere is an excellent model to study microbial-physicochemical interactions during degradation of the herbicide MCPA. Whereas during the first phase of SPP 1315 we focused on bacterial and fungal abundance at the soil litter interface and carbon flow between different compartments, the second phase will be devoted to elucidating complex regulation mechanisms of MCPA degradation in the detritusphere: (1) At the cellular level, co-substrate availability and laccase abundance might be important regulators, (2) at the community level, bacteria harbouring different classes of tfdA genes might control degradation of MCPA and (3) at the microhabitat level, interaction between MCPA degraders and organo-mineral surfaces as well as transport processes might be important regulators. The concept of hierarchical regulation of MCPA degradation will be included into the modelling of small-scale microbial growth, MCPA transport and MCPA degradation near the soil-litter interface.