一株新奇藻华生防功能菌的生物学特性、作用机理与应用基础

Aimed at the scientific frontier research on "environmental evolution and ecological safety in coastal waters" and based on current situation and serious problems of harmful algae blooms（HABs） in China, we will take advantage of the combination with new technologies of multi-sciences and the features of bioremediation driven by marine microbes to investigate how they regulate and control HABs, especially the algicidal effect of a special microorganism which was newly isolated by our research group and was suspected to be parasitic and non-viral but with high algicidal activity. All the research is based on the acquisition of axenic culture of HAB-causing algae and the frontier of bio-control studies of HABs. For this special algicidal microorganism, these aspects below will be concerned. Firstly, to illustrate what is it and which Taxonomic status should it be in? Then to find out its optimum algicidal conditions and algicidal rules，especially the algicidal process and mechanism. At last, to carry out relative ecological simulation experiments to study its effectivity and safety for HAB control. It is expected to obtain new and of our own property microorganisms and gene resources with regulatory functions on HABs species, and provide scientific evidence and bioremediation ways for HAB control by marine microorganisms. Results of this study will help one to expand and improve algae-microbe relationship theory and develop relative bioremediation techniques which means a lot for marine ecology security, mariculture development and human health.

本申请项目应对国家高度关注的近海环境演变与生态安全问题，瞄准有害藻华生物调控的国际前沿研究，整合多学科技术优势，采用本课题组新分离到的一株疑似寄生性、非病毒性、高效溶藻性的新奇微生物为实验材料，以自主发明的对藻细胞无菌化技术处理获得的无菌、真核藻华藻为模式生物，进行该特殊微生物强效杀灭有害藻华藻的一系列研究。首先确定其生物学本质及分类地位；进而查明其作用条件、作用规律与生态特点，尤其注重该特殊微生物对有害藻华原因种作用的关键过程与机制的阐释；再者进行利用该特殊微生物作为生防工具的相关生态模拟实验及其应用技术探讨。预期获得具有我国自主产权的、对有害藻华生物具有重要调控功能的新的微生物资源及其基因资源，拓展并完善海洋生态学理论，提供海洋微生物有效调控有害藻华的科学依据与生物防治技术。

本研究应对国家高度关注的近海环境演变与生态安全问题，瞄准有害藻华生物调控的国际前沿研究，整合多学科技术优势，从三角褐指藻平板上直径为2 cm的溶藻斑中分离得到一株特殊溶解微生物，荧光显微镜和变性梯度凝胶电泳的结果表明，该微生物在溶藻环境当中的数量相当稀少，在使用不同的培养基后，我们终于分离得到一株对三角褐指藻具有溶藻效果的微生物，命名为KD531，经鉴定，它属于红杆菌科的Labrenzia属。KD531的溶藻活性受到温度和pH值的影响，但对光照不敏感。同时KD531对多种藻类，尤其是绿藻，具有良好的溶藻活性。在KD531的破坏细胞壁作用下，目标藻的总蛋白、总磷脂及总碳水化合物的含量均发生变化。趋化实验及显微观察结果表明，KD531可以直接向目标藻细胞移动并与藻细胞直接接触，这种菌株与藻细胞的直接接触是菌株KD531溶藻机制的基础。上述研究成果帮助我们拓展了“菌-藻”关系理论，促进了生物修复技术的发展，对海洋生态安全、海洋渔业发展及人们的身体健康具有重要的意义。