The Research On Extraction Microalgae Lipid By Enzyme Hydrolyzation

The research of this paper focused on collecting cells and breakingcell, in order to extract lipid. It found a solution for preparing thebiodiesel.60%ion degree of the CPAM is used for flocculating chlorellavulgaris fermentation process. The concentration is0.05‰, PH is10,the settlement reached20min, almost all chlorella vulgaris subside. R(TSS) is99%. Four cell broken methods, enzyme hydrolysis, acidmethod hot water and enzymatic hydrolysis by pretreatment werecompared in the paper. The concentration of chlorella vulgaris was25g/L, With the addition of4g/L neutral protease (temperature of42°C,pH of7, and reaction time of4h), the extraction rate of lipid reached80%. The enzyme efficiency of neutral protease was better thancellulose and alkaline protease. Tween hydrolysis process, lipidextraction rate increased by about5%. The mixture of enzymes wereused in the experiment. The optimum rate was cellulase and neutralprotease4:3, cellulase and alkaline protease2:1.Acid method played a obvious role in cell broken. Therefore, the high lipid extraction rate could be obtained with the algae and2mol·L-1hydrochloric acid at100°C for10min, using hexane extraction. When thetemperature of hot water is60°C, the lipid extraction rate is low. But theextraction rate increased rapidly with increasing temperature. Hot waterhas also always had some degree in cell broken. The100percent ethanolwas used to extraction pigment and extraction rate reached90%.However, the pigment was broken down at60°C. whatever pigment is insour environment, alkaline environment, it can be broken down.After hot water remained90°C for one hour, the concentration ofcellulose fell0.5g/L. Similarly, with the neutral protease enzymatichydrolysis, lipid yield increased by5%. When the temperature of hotwater was80°C, the concentration of alkaline protease fell from4g/L to3.5g/L. However, when hot water was60°C for4h, the concentration ofneutral protease and alkali protease was3.5g/L,3g/L respectively. Oilextraction rate was up to85%. Lipid extraction rate was70%with theconcentration of cellulase was2g/L, hot water remained80°C for5h.Optimization of process by the pretreatment of0.5mol/LOrthophosphoric acid, oil extraction rate is70%. Similarly, Afterchlorella vulgaris by the pretreatment of0.1mol/L Orthophosphoric acid,the concentration of neutral protease was2g/L, lipid yield reached85%.when the concentration of alkaline protease was2.5g/L, oil extraction ratenear to80%.