Isolation And Fatty Acids Analysis Of An Oil-producing Cyclotella Sp.

With the rapid population growth,the demand for edible oil is also increasing.Because microalgae is rich in polyunsaturated fatty acids,easy to cultivate,and low in cost,it has become a new breakthrough in the production of edible oils.In this study,a strain of Cyclotella in Shanxi Province was isolated from Manghe Nature Reserve in Shanxi Province.In order to find the the optimal culture conditions and maximum oil yield,the strain was cultivated under different salinity and different light conditions.This study can provide a theory and basis for the further development of microalga edible oils and oil productivity.The main findings are as follows:(1)Water samples were collected from the Manghe Nature Rserve in Shanxi Province,and a plankton diatom was isolated.Microscopic observation and molecular biological identification were performed to determine that the algae strain was Cyclotella menegheniana.Analysis of the fatty acid composition revealed that the fat content was 13.45%.Its fatty acids are mainly palmitic acid(C16: 0),myristic acid(C14: 0),and eicosapentaenoic acid(C20: 0).(2)To investigate the growth of Cyclotella menegheniana and the effect of oil content at different salinity levels.In this study,five different salinity gradients of 0 g/L,5 g/L,15 g/L,25 g/L,35 g/L,and 45 g/L were set,and their OD values,biomass,photosynthetic activity and oil content.The results showed that when the salinity was 5 g/L,15 g/L,25 g/L,the biomass of the algal strain was higher than that of the control group.And its pigment content and photosynthetic activity were significantly higher than those of the control group(p<0.05).When the salinity is 15 g / L,the growth condition is the best,and its biomass and fat content are 0.27 g / L and 21% respectively.From this,it is known that 15 g / L is the optimum growth salinity of the algae strain.(3)In order to explore the growth of the algae strain and its effect on oil content under different light conditions.Three photometric gradients of 40 μmol photons/(m2 · s),80 μmol photons/(m2 · s),and 120 μmol photons/(m2 · s)were set up,and their OD values,biomass,and photosynthetic activity and fat content were measured.The results show that the final biomass is the highest at 40 μmol photons/(m2 · s),and the fat content was 18.7%.From this,40 μmol photons/(m2 · s)was determined as the optimal light intensity for photosynthesis of this algae strain.