太湖溶藻细菌溶藻群体效应信号分子的分离鉴定和信号分子对溶藻进程的调控规律研究

It is a promising technology to control cyanobacterial blooms by use of algicidal bacteria. Algicidal bacteria usually requires a cell density threshold to start their algicidal process, which means the quorum sensing phenomenon. The concentrations of algicidal bacteria in lakes could reach the cell density threshold only in few days during a year. Based on 3 representative algicidal bacterial strains from Lake Taihu, the quorum sensing signaling molecules of algicidal bacteria will be isolated and purified using dextran gel and High pressure liquid chromatography, and the molecular structures will be resolved through high resolution mass spectrum and nuclear magnetic resonance. The algicidal cell density threshold of algicidal bacteria will be reduced through adding Quorum sensing signaling molecules in laboratory scale, the satisfied algicidal results will be achieved in low cell concentration of algicidal bacteria, and the law of active regulation and control by using Quorum sensing signaling molecules for algicidal process will be obtained. By continuous sampling analysis in 3 lake regions of Lake Taihu during 2 years, the law of related variation among concentrations of quorum sensing signaling molecules, algicidal compounds, algicidal bacteria and cyanobacteria in lake Taihu will be obtained, the natural regularity of algicidal process influenced by quorum sensing signaling molecules in four seasons of a year will be revealed. The findings will have an important value for deeply understanding the mechanism of algicidal quorum sensing, and will supply a basis for the development of biological control technology for cyanobacteria blooms in view of regulation of algicidal quorum sensing signaling molecules in low algicidal bacteria concentrations of Lake Taihu.

运用溶藻细菌控制蓝藻水华很有发展前景。溶藻细菌通常需要达到一个细胞密度阈值后才开始溶藻，即具有溶藻群体效应现象，而湖泊中的溶藻细菌浓度一年中只有很少的时段能够达到这个阈值浓度。本申请课题针对3株代表性太湖溶藻细菌，应用葡聚糖凝胶分子筛和液相色谱分离纯化溶藻细菌的溶藻群体效应信号分子，以高分辨率质谱结合核磁共振解析鉴定其分子结构；在实验室规模中通过添加信号分子以降低溶藻阈值实现低细胞浓度下溶藻细菌的有效溶藻，获得运用信号分子主动调控溶藻进程的规律；通过在太湖3个湖区的2年高密度连续取样分析，获得湖水中溶藻群体效应信号分子浓度与溶藻活性物质浓度、溶藻细菌浓度及蓝藻浓度间的相关性变化规律，揭示在一年不同季节中溶藻信号分子对于溶藻进程的自然影响规律。研究结果对深入认识溶藻群体效应机制有重要价值，为开发基于溶藻群体效应信号分子调控的、在太湖的实际低溶藻细菌浓度下应用的生物控藻技术提供研究基础。

运用溶藻细菌控制湖泊的蓝藻水华是很有潜力的发展方向，溶藻细菌通常需要达到一个细胞密度阈值后才开始溶藻，即具有溶藻群体效应现象。而自然湖泊中的溶藻细菌浓度一年中只有很少的时段能够达到这个阈值浓度。本课题从前期建立的溶藻细菌菌株库中的30株溶藻细菌中选择了2株代表性太湖溶藻细菌，应用葡聚糖凝胶分子筛和液相色谱柱分离纯化了溶藻细菌的溶藻群体效应信号分子，以高分辨率液相色谱-质谱联用和核磁共振技术解析鉴定了其分子结构；在实验室规模中通过添加信号分子以降低溶藻阈值实现了低细胞浓度下的溶藻细菌有效溶藻，获得了运用信号分子主动调控低细胞浓度下溶藻细菌溶藻进程的规律；通过在太湖3个代表性湖区的2年高密度连续取样分析，获得了实际湖水中溶藻群体效应信号分子浓度与溶藻活性物质浓度、溶藻细菌浓度及蓝藻浓度间的相关性变化规律，揭示了在一年不同季节中溶藻群体效应信号分子对于溶藻进程的自然影响规律。研究结果对深入认识溶藻细菌的溶藻群体效应机制有重要价值，为开发基于溶藻群体效应信号分子调控的、在实际水域的低溶藻细菌浓度下应用的生物控藻技术提供了研究基础。