The Effect Of Carbon Resource On Lipid Accumulation In The Scenedesmus Sp Cells

As a clean and green renewable energy,biomass energy has an great important significance for the crisis of energy shortages and global greenhouse effect. The work is aim to investigate the carbon resource demand for biomass production and the lipid accumulation in cells, to probe the impact of the amount of carbon added for carbonic anhydraseand photosynthesis system activity.The growth curve of Scenedesmuswith carbon source added and without supplemental carbon source show that, added carbon sourceis essential for Scenedesmus cells growth. When cultured in the low CO;concentration range, the biomass production has an increase with increasing concentrations of CO2. Whenthe CO2concentration attain0.5mmol/L, the biomass had the highest production3.86g/L, lipid content got to46%and lipid productivity was1.8g/L. From the result of Carbonic anhvdrase activity under different concentrations of CO2, we found when cultured in the low concentrations of CO2, algal cell extracellular carbonic anhydrase activity is high, reached to10.5EU. When inhibit the carbonic anhydrase activity, photosynthesis efficiency of algal cells are also inhibition. Fv/Fm values decreased from7.1to5.9. Solar energy thermal damage NPQ value increased from0.26to0.43.Extracellular carbonic anhydrase activity was significantly reduced or even disappeared as the CO2concentration increasing to0.5mmol/L, the photosynthesis efficiency is no longer influencedby carbonic anhydrase activity of cells.The results show that, the carbon source with a preferred supplementary concentration range is0.5-0.6mmol/L. in this concentration range, carbon added are both efficient for biomass and lipid accumulation in cells, and also to avoid the waste of the carbon source. Extracellular Carbonic anhydrase start CCM Mechanism when the carbon concentration is below that concentration range. The results has important significance for rational utilization of the carbon source to culture microalgae cells, improve biomass accumulation and intracellular lipid content. At the same time, the study also provides a theoretical basis for the Scenedesmus sp to large-scale ecological farm.