Effects Of Different Calcium Concentrations On The Growth And Cell Wall Characteristics Of Microcystis

The harm of Microcystis blooms to environment in our country is increasingly prominent.It is not only damage the water body, but also the survival of other species in the water andwater security of domestic water. And our country’s spending on water treatment is also very handsome but unrewarding. Investigate its reason, the present stage of Microcystis blooms outbreak of cytology mechanism is still not understood clearly, that is why the problem cannot be fundamentally solved. This study from the group of Microcystis exist in natural water body is more likely to get the ecological advantages as foothold. These two different states of Microcystis in the lab are in groups （XW01） and single cell （PCC7806） we used to insight into the relationship between calcium ion and the state of Microcystis group formation. The following is the research contents and results.1、EDS techniques were used to identify the cell surface elements and confocal laser scanning microscope was used to detect the micro capsule algal intracellular calcium fluorescence intensity. The results reflected the fact that the group of Microcystis cells and its cell wall of calcium ion adsorption capacity are bothmuch higher than single cell state Microcystis. After dialysis to remove calcium ions we found that groups of Microcystis has a better ability of maintaining calcium to go through the bad environment.2、By the determination of EGTA effective inhibition concentration and microscopy results, determine the completely without calcium BG11 medium formula. PCC7806 and XW01 medium EGTA concentrations were 24.5 umol/L,42.0 umol/L. With fewer Ca²⁺ concentrations, state of algal groups began to become loose, group size smaller. In the certain concentration range, with the increased concentration of Ca²⁺, Microcystis cluster rate will also increase.3、SEM observation results showed that the group of algal polysaccharide content is much higher than single cells of algaebased on the two kinds of Microcystis. In order to study the relationship between calcium ion and Microcystis of Polysaccharide synthesis wedesigned without calcium, low calcium （5 mg/L）, high calcium （60 mg/L） in three different calcium ion concentration of BG11 medium. Then the two Microcystis extracellular polysaccharide, polysaccharide in cell wall and polysaccharide in cells were determined. The results showed that with the increase of calcium ion concentration, the ability of a certain number of algal cells to synthesize polysaccharide increased. Cells and synthesis of polysaccharide secreted extracellular mostly.4、To a comprehensive understanding of calcium ions influence on Microcystis growth, cultured with three different calcium concentrations to develop a series of physiological indexes measured the two strains of algae. From the results we concluded that, when the concentration of calcium ion beyonds 60 mg/L, Microcystis growth and the synthesis of protein produced certain inhibition. Compared to the unicellular algae, group for Microcystis inhibition of calcium ion concentration is higher. But this degree of calcium ion concentration promoted the Microcystis photosynthetic pigment, the synthesis of chlorophylla,carotenoids and nitrate reductase activity. This state of promoting role in a group is more apparently, the micro capsule group algal cells have a higher productivity. Microcystis under adversity can improve the activity of alkaline phosphatase, and group of Microcystis the alkaline phosphatase activity was much higher than that of single cell Microcystis which has higher response capacity to bad environment.According to the results of this study, groups of Microcystis cell walls are more likely to be combined with calcium. A certain amount of calcium ion concentration has a promoting effect on the synthesis of cell wall polysaccharides and the formation of the group.