循环水产养殖系统中玉米芯介导的反硝化微环境特征研究

项目名称： 循环水产养殖系统中玉米芯介导的反硝化微环境特征研究

项目编号： No.31502172

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 农业科学

项目作者： 邵留

作者单位： 上海海洋大学

项目金额： 21万元

中文摘要： 生物反硝化对循环水产养殖系统氮的去除有重要影响。前期研究发现，以玉米芯同时作为反硝化微生物碳源和载体可有效降低循环养殖水中的硝酸盐浓度，获得较高脱氮效率。本项目拟对玉米芯介导的固相反硝化微环境，特别是基质传递与微生物分布间的关系展开深入研究。借助微电极技术探究生物膜垂直方向上特征参数（氧和硝酸盐）浓度的变化规律，建立扩散-反应方程，获得氧和硝酸盐反应动力学；借助扫描电镜和激光共聚焦显微镜分别从一维及三维角度探究微生物形态变化，在冷冻微切片基础上，借助高通量测序技术分析生物膜不同层面微生物群落结构变化特征，揭示微生物形态及分布动态变化规律；综合以上实验，深入探讨微生物、氧及硝酸盐三者的动态平衡及内在关系，解析三者共同形成的微环境对玉米芯介导的反硝化工艺脱氮效果的影响。本研究将进一步揭示固相反硝化脱氮机理，为固相反硝化工艺的优化提供理论和技术支撑，对推动水产养殖可持续健康发展具有重要意义。

中文关键词： 生物膜；微电极；固体碳源；脱氮；反硝化

英文摘要： Biological denitrification has a pronounced effect on the removal of nitrogen from RAS (recirculating aquaculture system). However, to date, seldom information is available of denitrification mechanism mediated by solid carbon source in RAS.. According to previous study, we have discovered that high nitrate removal rate was found when corncob used as carbon source and biofilm carrier. In order to explore the mechanism of denitrification microenvironment clearly, in present research proposal, we will further investigate the relationship between microbial community structure and substrate transmission within biofilm. Firstly, microelectrode technique will be employed to measure the concentration of characteristic parameters (including oxygen and nitrate) with the increasing depth of biofilm. Based on the profiles, the microenvironment characteristics of exchange flux and utilization rates of oxygen and nitrate will be evaluated. And then, to make clear the change of microbial distribution with the increasing depth of biofilm, high-throughput sequencing technique will be employed to analyze the microbial community structure pretreated by frozen section. Besides, scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM) will also be used to explore microbial morphological changes from one-dimensional and three-dimensional, which help reveal the variation of the dominant microbial species on biofilm’s vertical direction. Finally, in order to get a clearer explanation about denitrification microenvironment mediated by corncob, based on the results received, the dynamic balance and internal relations among microorganism, oxygen and nitrate will be evaluated. . The present research can provide theoretical and technical support for denitrification in RAS wastewater treatment. It will be meaningful for water resource reuse and sustainable development of aquaculture.

英文关键词： biofilm;microelectrode;solid carbon source;nitrogen removal;denitrification