Influence Of Rare-Earth Elements On The Growth Status Of Chlorella Pyrenoidosa And Microcystis Aeruginosa

For a long time,The researcher has been paid much attention to the influence of rare earth elements on algae growth and the relationship between rare earth and eutrophication.It is clear that the mechanism of action is important for controlling water eutrophication.In recent years,rare earth elements have been widely used in petroleum,chemical and other industrial fields,as well as medicine,agriculture and other aspects,The rare earth elements that exist in the lithosphere move to the hydrosphere and the biosphere gradually,finally,the rare earth content in the water environment continues to grow.In this paper,two kinds of algae,Chlorella pyrenoidosa and Microcystis aeruginosa,were cultured in the laboratory.And studied a number of aspects,including algal cell biomass(algal density and specific growth rate),photosynthetic capacity(chlorophyll a content and photosynthetic rate),Oxidase reaction system(superoxide dismutase SOD activity and catalase CAT activity),nutrient uptake(nitrate and total phosphorus),conductivity,cell membrane integrity,protein analysis(3D fluorescence analysis and protein quantitative analysis),as well as the ability of algal cells to enrich the rare earth ions and so on.The effects of eight kinds of rare earth La,Ce,Pr,Nd,Ho,Tm,Lu and Y on the growth status of two kinds of algae were studied,which provides strong evidence for the influence of rare earth elements on ecosystems,and provides the basis for the prevention and control of rare earth pollution.Under the experimental conditions,it can be concluded that the rare earth elements have the effect of "low and high inhibition" on the growth of the two algae cells,but the dosage range of different algae is different.When the concentration of rare earth elements was less than 100?g / L,the growth of Chlorella pyrenoidosa was promoted(P <0.05),but inhibited more than 1000?g / L(P <0.05),While Microcystis aeruginosa was more resistant to rare earth elements than chlorella,When the concentration of rare earth elements reached 1000?g / L,the growth of Microcystis aeruginosa could be promoted(P <0.05),and be strongly inhibited at 2000?g / L(P <0.05).The results of further studies indicate that the addition of rare earth elements can change the chlorophyll a content of algae,affect the photosynthetic efficiency of algal cells,change the photosynthetic capacity of algal cells,and change the algal cells to absorpt nutrient(nitrate and total phosphorus),the conductivity of the culture medium,Thereby promoting the algal cells to start their own defense mechanism,resulting in SOD and CAT to resist the adverse environment,algal cell membrane integrity and protein content also be changed.