Microcystissp are key players in the global phenomenon of toxic cyanobacteria blooms, which endanger the water quality in fresh water bodies. As such, they have been a research focus for decades.
In this research the interactions between bacteria isolates, which have been obtained from scum samples of Microcystis sp bloom in the Kinneret and from Microcystis sp cultures that were obtained from Kinneret (Microcystis MBK, Microcystis MGK), and between cyanobacteria are investigated. The interactions occur using quorum sensing systems and also alternative means. The effect of the quorum sensing signal molecule N-Acyl homoserine lactone (AHL) on Microcystis sp has been studied.
It was found that the growth rate of Microcystis MGK that has been treated with AHL was significantly lower than the control. When Microcystis MGJ was treated with AHL, the response was very different. The treated sample reached a higher density, compared to the control, and did not develop polysaccharides on the vessel walls.
Treatment of Microcystis MGK by bacteria isolated from Microcystis sp cultures did not change the growth rate compared to the control, but treatment by bacteria isolated from the scum inhibited the Microcystis MGK growth.
These results show complicated interactions between Microcystis sp and other bacteria in their surroundings. A deeper understanding of this system may provide the means to predict, exterminate, and even prevent bursts of toxic cyanobacteria blooms.
