铜绿微囊藻(Microcystis aeruginosa)与三种丝状蓝藻间的相互作用

Allelopathic effect between Microcystis aeruginosa and three filamentous cyanobacteria

研究了单细胞铜绿微囊藻和三种丝状蓝藻(水华束丝藻、水华鱼腥藻及土生席藻)间的相互作用,包括以下两个方面的内容:①铜绿微囊藻细胞滤出液对水华束丝藻、水华鱼腥藻及土生席藻生长的影响;②水华束丝藻、水华鱼腥藻及土生席藻细胞滤出液对铜绿微囊藻生长的影响．研究发现,当滤出液浓度为60％(滤出液与BG11的体积比为3:2)时,制绿微囊藻细胞滤出液对水华束丝藻、水华鱼腥藻的生长有显著促进效果,尤其对水华束丝藻的作用更加明屁;对土生席藻的生长却起着微弱的抑制作用,仅表现于100%细胞滤出液中,对铜绿微囊藻而言,土生席藻细胞滤出液对其的生长起着显著抑制作用,浓度越高、抑制作用越强;而水华束丝藻、水华鱼腥藻仅在100％细胞滤出液中才表现出微弱的抑制作用．为验证营养盐浓度差异是否影响滤出液的作用效果,进行了无机营养盐(NO3-N、NH4+-N、PO4-P)干扰的消除试验．结果表明,无机营养盐(NO3-N、NH4+-N、PO4-P)的改变并不影响滤出液的作用效果,从而我们推测水华蓝藻之间存在着化感作用．本研究为解释自然水体中藻类种群演替的原因,深入认识水华蓝藻的动力学机制提供了新的实验证据．

Allelopathy, the release of extracellular compounds that have an effect on the growth of other microorganisms, may be one factor contributing to formation and/or maintenance of cyanobacterial blooms. In this paper, the allelopathic effect between single-cell Microcystis aeruginosa and three filamentous cyanobacteria Aphanizomenon flos-cquae, Anabaenaflos-aquae, Phormidium mucicola was investigated. The experiment was conducted to find out the allelopathic effects of cell-free filtrate on the growth of different target organisms ： 1. the cell-free filtrate of M. aeruginosa on Aphanizomenon flos-aquae, Anabaena flos-aquae and P. mucicola ; 2. the cell-free filtrate of Aphanizomenon flos-aquae, Anabaena flos-aquae and P. mucicola on M. aeruginosa. The results demonstrated that M. aeruginosa could accelerate the growth of Aphanizomenonflos-aquae and Anabaenaflos-aquae, and slightly inhibited P. mucicola. On the other hand, the growth of M. aeruginosa was slightly suppressed by Aphanizomenonflos-aquae and Anabaena flos-aquae, but heavily inhibited by P. mucicola. The inhibition by P. mucicola was enhanced with the increase of concentration of cell-free filtrate. Furthermore, the allelopathic effect between single-cell M. aeruginosa and three filamentous cyanobacteria Aphanizomenonflos-aquae, Anabaenaflos-aquae, P. mucicola was not influenced by the change of the concentration of inorganic nutrients in cell-free filtrates. It suggests that the inter-species competition existed in cyanobacteria. The present study is implicated in illustrating dynamics of the cyanobacterial bloom.