Degradation And Preliminary Application Analysis Of Environmental Enzymes To Microcystis In Lake Erhai

Objective：1. To study on the growth law and some physiological characteristics of Microcystisaeruginosa isolated from lake Erhai.2. To make environmental enzymes and screening the algicidal algae to Microcystisfrom lake Erhai, select the strongest Algicidal effect of apple enzyme to researchand discuss the algicidal mechanism; ultimately, research the Algicidal effect ofenvironmental enzymes to wild algae of lake Erhai.Methods：1. Purified Microcystis aeruginosa was separated with water droplets method and thespread plate method. microscopic was used to count the density of algal cells;chlorophyll and carotenoid were extracted with90%acetone and ELIASAdetermination of its content.2.10%(v/v) of environmental enzyme was add to algal that including0.457μg/mLof initial chlorophyll-a. Ultimately, determine the change of chlorophyll-a.3. The content of chlorophyll-a and the clearance rate that were determined onadding apple enzyme with the volume from0to3ml, the dilution of0to10-5times, and different processing[the stoste, the stoste needs to be collated twicethrough the filter of0.22μm, high-temperature sterilization(121℃,0.1Mpa,20minutes), centrifugation of15minutes with12000r/min and0.25%trypsintreatment15minutes in Microcystis.4. Collect the samples from algae bloom of lake Erhai and environmental enzymeswere in accordance with the different doses to confirme the efficiency.Results:1. Microcystis aeruginosa cells density in a linear relationship with OD665, R2=0.9931, Algal cell growth rate in sixth days to reach a maximum of0.524,Chlorophyll and Carotenoid content increased gradually change over time.2. Compared with the control group，All the samples had decrease in the content of chlorophyll-a，especially apple enzyme had the greatest reduction. Furtherresearch shows that: With the increasing of apple enzyme，the clearance ofchlorophyll-a increased and then decreased，and the function was maximum whenadd0.6ml apple enzyme into the fluid of microcystis;94.475%chlorophyll-a wasdumped at the fourth day. Diluting the apple enzyme with distilled water, and thecleaqrance of chlorophyll-a increased and then decreased with the increasingdilution multiple; when it was diluted by10-1times,95.271%chlorophyll-a wasdumped at the fourth day. The apple enzyme dealed with different ways hasalgicidal function，and the clearance of these different treatments at the fourth dayare as follows: stoste is81.400%, the stoste needs to be collated twice through thefilter of0.22um is84.358%, high-temperature sterilization(121℃,0.1Mpa,20minutes) is80.177%, centrifugation of15minutes with12000r/min and radius of3cm is79.524%and that of resposed15minutes with0.25%trypsin is79.299%.3. With the increasing of environmental enzyme，the clearance of chlorophyll-aincreased and then decreased，and the function was maximum when add2%(v/v)of environmental enzyme into the fluid of microcystis.Conclusions:1. This Microcystis aeruginosa growth is in line with the “S” shaped curve; celldensity and absorbance is linearly related and the growth rate of the maximum onthe sixth day.2. These environmental enzymes have Algicidal effect to Microcystis, especially,apple enzyme has the strongest Algicidal effect and Algicidal curve is stable.Furthermore, the Algicidal mechanism is indirect action and produce an hightemperature resistance of nonprotein substance to Microcystis. Besides,Environmental enzymes can Algicidal many kinds of the mixed wild algae andhave maximum effect to remove algae at its rate to2%of volume.