Study Of Microcystis Phycobiliprotein Used As Photosensitive Bactericider And Antifungal

Because of human activities, the intensified eutrophication in water lead to freshwater algae blooms,and the accumulation of large number of algal body in the water form water blooms. Accumulation of blue-green algae in the water affect the ecological landscape and tourism seriously, they can also decline the quality of drinking water and the production of aquaculture.Coping with water blooms,direct fishing is the most direct measures.But pulled in cyanobacteria direct piled up together, if did not handle in time,the harmful material such as MC will be easy to release after the death of algae.So recycling the algaes can relieve cyanobacteria hydration phenomena, avoid secondary pollution, and achieve the purpose of rational utilization of resources.Microcystin algae is the dominant algae of the chaohu algal bloom, the cells of it contains abundant of microcystin algae PBP. The high purity of PBP is a kind of high value-added products. The PBP is a kind of photosensitizer. Rational utilization of microcystin algae PBP spectral characteristics to product the corresponding development of products will have great business interests.In conclusion we carried out in chaohu lake cyanobacteria extract of microcystin algae PBP, the study of the photosensitive properties of the concrete research include the following three parts:1. The extraction of microcystin algae PBPIn this experiment, using the method of swelling burst, burst the cell wall extraction PBP. The maximum absorption peak of PBP is 620 nm, maximum fluorescence peak at 650 nm, which indicate its main composition is phycocyanin. Extraction of PBP purity was 0.9, and HPLC testing proved that there is not MC residue in it, which meet the requirements of the purity of food grade PBP. The PBP income rate is 10.50%.2. The research of photosensitive damage for prokaryotic cells of PBPThis experiment using microcystin algae PBP to estimate the photosensitive damage for E. Coli, P.aeruginosa, S.aureus, B. subtilis (Illumination intensity:26 klx). The experimental results showed that in natural light(Illumination intensity:26 klx) PBP on S.aureus and B. subtilis photodynamic damage half lethal dose is 75 mu g/mL, for e. coli and P.aeruginosa the damage is not obvious. It shows that microcystin algae PBP for gram positive bacteria have better photodynamic killing effect, for gram-negative bacteria have not obvious effect. The result of confocal laser research shows PBP can through gram-positive bacterial cell walls into the plasma membrane, but could not enter inside the cell membrane of gram-negative bacteria. Indicate PBP photosensitive destruction results associated with the cell wall structure of gram-negative bacteria.3. The research of photosensitive damage for eukaryotic cells of PBPEukaryotic microorganism A. flavus, A. niger photosensitive killing experiment results show that:under the condition of photodynamic damage (Illumination intensity:26 klx) the PBP to A. flavus, A. niger half fatality rate is 75 mu g/mL. It shows that the photodynamic damage for eukaryotic cells of microcystin algae PBP have obvious effect. During photosensitizer microcystin algae PBP photosensitive destruction generate increased ROS, which shows that exist type I photosensitive reaction in the process of photosensitive killing. Under the dark state with PBP incubation mammalian cells 2h after laser confocal detection showes that PBP can enter the cytoplasm, but unable to enter the nucleus. And PBP are dispersed in the cytoplasm that is likely to locate on the type of lysosome structure. After Photodynamic damage laser confocal observation results show that the nucleus mass ratio down, PBP can enter the nucleus, and positioning in the region of the nucleolus of PBP quantity is more. The possible reason is that the PBP gathered in the region of the nucleolus than other areas, or after PBP together with the substance in nucleoli can enhance the fluorescence. PBP in cells is more likely to be negatively charged, thus could combine with alkaline proteins in nucleoli to increase its content in the nucleolus or change its fluorescence properties.To sum up, the PBP extracted from chaohu microcystin algae has certain commercial potential.The PBP can be developed as disinfectant or agricultural fungicide in the field of public health. And the maximum absorption wavelength is at 620 nm, with a larger penetrability,it can be used as a photosensitizer in photodynamic therapy.