产油微藻的筛选及其培养过程优化分析.docx

ABSTRACT
The dilemma involved fossil fuel conducted to the passion of biofuel. But the existing biofuel was inapplicability. Combined with the adaptability of land and water, high growth rate and lipid content microalgae contributed to the feasibility of microalgae biofuel (biodiesel) production.
In current study, a native marine oleaginous microalgae was isolated and identified as Nannochloropsis gaditana. In consistent with previous study, N. gaditana Q6 was influenced by macronutrients, with NH4HCO3 and NaH2PO4 as the optimal nitrogen and phosphate resources respectively. Moreover, NH4HCO3 exerted positive effect on biomass but negative one on lipid accumulation, while the correlation between NaH2PO4 and biomass production was in agreement with that involved lipid accumulation. Different with above, carbon addition exhibited negative influence on
N. gaditana Q6; NaHCO3 resulted in severe co-precipitation of biomass with insoluble salts, which exerted negative impact on the harvesting and lipid extraction, whilst glycerol-induced lower photosynthesis efficiency and stress condition contributed to lower biomass and lipid yield. Thus, autotrophic cultivation without carbon supplement was the optimal trophic type for N. gaditana Q6.
As the essential micronutrients, Fe and Mn play critical role in biomass accumulation. And N. gaditana Q6 was more sensitive to the variation of initial Fe concentration than that of Mn. The total biomass production process was positive influenced by Fe, and Fe-induced high nitrogen assimilation conducted to stress condition and lipid accumulation in the later stage.
As a marine microalgae, N. gaditana Q6 was positive affected by salinity. Attributed to the inhibition on photosynthesis and nutrient assimilation, high light intensity exhibited negative impact on biomass production but positive one on lipid accumulation. The promotion of inoculum size on biomass production was only valid in the early stage, with 20 mg·L-1 as the optima