Screening Of Dominant Algae Strains For Lipid Accumulation Of Scenedesmus Bijuga Under ARTP Radiation

In recent years,the development and utilization of microalgae biodiesel have become the focus of global biomass energy.More and more attention has been paid to biomass energy with the promotion of China’s "the belt and road " and "13th Five-Year Plan".In this paper,the growth morphology,triglyceride accumulation,photosynthetic activity and other characteristics of Scenedesmus bijuga FACHB-78 were studied under the conditions of Na Cl concentration of 0～45 ‰ and the optimal salt stress condition was determined.And the microalgae strains were screened out after atmospheric room temperature plasma ARTP)radiatio for facilitate further research on the production and utilization of microalgae biodiesel,which had great advantages for the accumulation of triglycerides under the conditions of salt stress.For the starting microalgae strain FACHB-78 under the conditions of Na Cl concentration of 0～45 ‰,the results showed that with the increase of salinity,the density of algae cells gradually decreased,the ratio of chlorophyll a content to carotenoid content gradually increased,but the accumulation of triglyceride increased first and then decreased.When the salinity was 10‰,the density of algae cells was26.30 % lower than that in normal medium,and the content and production of triglyceride were both increased to maximum values of 250.88 mg/L and 33.41 %respectively,which were 97.05 % and 82.09 % higher than those in normal medium,and the photosynthetic activity was good.It was determined that at a salinity of 10‰,the triglyceride accumulation was optimal under the premise of no significant loss in growth rate of the microalgea cells.The FACHB-78 cultured at a salinity of 10‰ was subjected to ARTP irradiation.By comparing the growth rate,triglyceride accumulation,chlorophyll fluorescence parameters and lethality,then inoculate the microalgea that irradiation time was80 s and 120 s onto solid medium.Finally,two mutant microalgae strains 80-W and80-X with good genetic stability were selected.For mutant microalgae strains 80-W,80-X,under the conditions of Na Cl concentration of 0～45 ‰,the results showed that with the increase of salinity,the overall trends of the density of algae cells,the the ratio of chlorophyll a content to carotenoid content,the accumulation of triglyceride,and the chlorophyll fluorescence parameters were same as thses of the starting strain.However,the optimal salt stress conditions of 80-W was changed,and its salt tolerance was improved.The yield of triglyceride became highest under the salinity of 15‰,which was 220.01 mg/L.wasThe salt tolerance of 80-X had no change,but its triglyceride yield reached 296.14 mg / L under the salinity condition of 10 ‰,which was 18.04 % higher than the starting plant under the same salinity.After comprehensive comparison of various indicators,for the production of biodiesel,under the stress of salinity of 10‰,Scenedesmus bijuga FACHB-78 cells had greater advantages than algae cells cultured under normal medium.Screening microalgae strains 80-W and 80-X after ARTP irradiation has great advantages for the accumulation of triglycerides under stress conditions of salinity of 15‰ and 10‰,respectively.