纳米氧化锌对河流凋落物降解的影响及机制研究

Nano-ZnO is used widely because of its unique optical properties, high catalytic ability and antimicrobial activity, but it also brings harm to human beings and our environment. Currently, intensive studies are involved in the eco-toxicity of nano-ZnO on some single mode organisms, but the impact and mechanism of nano-ZnO on aquatic litter decomposition has not been reported yet. It was indicated that litter decomposition rate could be inhibited by nano-CuO and nano-Ag. Therefore, we attempt to explore the mechanism in the methods of biochemistry, molecular biology and nano-science. It will be studied including the transformation, migration and effect of nano-ZnO on decomposition rate in water-(nano-ZnO)-litter decomposition system. Changes of microbial diversity will be tracked to indicate the succession of microbial community under the influence of nano-ZnO. Furthermore, the dynamic of extracellular enzyme activity will be studied timely. We will analyze the intrinsic relationship between environmental behavior characteristics of nano-ZnO and microbial activity to fully reveal the mechanism of nano-ZnO on aquatic litter decomposition. This study can provide theory basis for research on environmental toxicology of nano-materials in aquatic ecosystem.

纳米氧化锌因其独特的光电性能、高效的催化能力和抗菌活性而倍受青睐，但同时也给人类和环境带来了一定程度的危害。目前，纳米氧化锌对单一模式生物的毒性研究较为深入，而纳米氧化锌对河流凋落物降解的影响及机制还未见报道。有研究显示，纳米氧化铜和纳米银对河流凋落物的降解过程具有抑制作用。因此，本项目拟综合运用生物化学，分子生物学以及纳米科学等方法，在水-纳米氧化锌-凋落物降解体系建立之后，探讨纳米氧化锌在该体系中的形态变化、运移规律及其对凋落物降解速率的影响效应；同时对体系内分解者微生物多样性的变化进行跟踪，揭示微生物群落在纳米氧化锌影响下的演替规律；并结合主要降解酶活性的动态变化，剖析纳米氧化锌的环境行为特征与分解者活性的相关性，从而全面揭示纳米氧化锌对河流凋落物降解的影响机制，为水域生态系统中纳米材料的环境毒理研究奠定理论基础。