Toxicity Mechanism Study Of Microcystis Phycobiliprotein As Photosensitive Insecticide

Harmful algal blooms,caused by water pollution has become the environmental issues of common concern,which induced by Microcystis blooms in freshwater bodies against the most serious category.The purpose of this test is from algae blooms which caused by outbreaks of advantage kind of extracting phycobiliprotein of Microcystis,according to their physico-chemical and biological properties used as photosensitive agent conduct insecticidal experiments.This way not only will make effective use of Microcystis but also overcome traditional organic pesticide residues from pesticides,bio-resistance problems and environmental issues.This paper,by model organism Drosophila melanogaster,Caenorhabditis elegans and the mutant CF1038,studies on phycobiliprotein of Microcystis photoactivated toxicity.By measuring the mortality of Drosophila melanogaster and Caenorhabditis elegans,we know the LC50 and lethal dose of Microcystis phycobiliprotein on Drosophila melanogaster and Caenorhabditis elegans.Microcystin-LR is toxic substances,produced by the metabolism of Microcystis.This study found that a certain amount of phycobiliprotein from Microcystis can degrade a certain amount of Microcystin-LR.Through researching phycobiliprotein of Microcystis on Spodoptea Frugiperda 21(SF21)of proliferation inhibition rate,the generation of intracellular malondialdehyde,the change of reduced glutathione in cells and through observing the site of action which phycobiliprotein of Microcystis on Caenorhabditis elegans by the fluorescence microscope,we study on phycobiliprotein of Microcystis of photosensitive effect and mechanism of the pesticide.Through the experiments,we conclude the results as follows:1.We determined that the LC50 of Drosophila melanogaster was 750?g/ml,and the lethal dose of phycobiliprotein of Microcystis in C.elegans was 4000?g/ml,and the LC50 of C.elegans(N2)was 80?g/ml,and the lethal dose of MC-PBP in C.elegans was 400?g/ml.While the control group hematoporphyrin monomethyl ether light-sensitive pesticide of LC50 to Drosophila melanogaster and C.elegans was 1000?g/ml and 400?g/ml,respectively.So phycobiliprotein of Microcystis has a better insecticidal effect when compared with hematoporphyrin monomethyl ether(HEME).2.50?g/mL of phycobiliproteins can make the 2?g/mL microcystin degradation in the sunlight.This shows that even if there is a small amount of microcystin remaining in the process of extracting phycobiliproteins,it will not cause algae toxin residueing in the course of using.3.The cell viability of Spodoptea Frugiperda 21(SF21)cells,the output of MDA and the content of GSH were assayed when SF21 cells were treated with PBP.(1)The inhibition rate of SF21 was 45%and65%at 24h and 48h post PBP treatment with irradiation,respectively.(2)The results obtained with TBA method showed that photoactivated PBP could induce MDA increasing in dose dependent manner.When the treatment concentration of PBP was 400?g/ml,the output of MDA at 24h and 48h post treatment were 86.79nmol/L and 137nmol/L,respectively.(3)The GSH level,however,exhibited a contrary tendency.When the treatment concentration of PBP was 400?g/ml,the GSH content decreased by 42%and 53%at 24h and 48h compared with the same concentration treatment without irradiation.All the evidence indicated that PBP had induced oxidative damageto SF21 cells.4.Treated with different concentrations of microcystins phycobiliprotein,observation of site of action of C.elegans by fluorescence microscope.Results found:in experimental group compared with the control group the C.elegans intestinal and gonad parts suffered different degrees of cell apoptosis.