Effect Of Fe³⁺ On Growth And Lipid Accumulation And The Expression Of Correlative Genes Of Three Typical Microalgae

The exhaustion of conventional fossil fuels, increasing of combustion-generated pollutants, and the raise in the price cause the development of new energy sources more and more important. The biodiesel is the clean renewable energy and the high quality substitute for traditional diesel. The biodiesel is the emblematical "the green energy", so strengthen the development of biodiesel will be propitious to the sustainable development of economy, the advancement of energy substitution, the reducing of the environment pressure, the control of the city air pollution. Microalgae are one of the most promising feedstoek owing to their higher oil yields and fast growth. Moreover, microalgae can grow in places away from the farmlands and free from fresh water, thus minimizing the damages caused to the eco-and food-chain systems. However, the produetion of algae for biodiesel has not yet been undertaken on a commereial scale, and one of the key factors is the produetion of organisms.Lipids content and the dry matter yield of microalgae could be modified by environmental conditions. To optimize the cultural conditions for inereasing lipids produetivity in some microalgae, and to explore some metabolic controlled factors relevant to lipids accumulation, the effect of iron Mg2+,Cu2+,Ca2+,Fe3+ in C. sorokiniana CS-01 and the effect of Fe3+ in Phaeodactylum tricornutum,C. sorokiniana CS-01,Isocrydid galbana on growth and lipids accumulation was investigated. In the last part of the work, pilot study of a conceptual process for producing biodiesel from microalgal oil was made. The primary subjects of the work include three parts as follows:(1) The effect of iron Fe3+,Mg2+,Cu2+,Ca2+ on growth and lipids accumulation in C. sorokiniana CS-01 respectively by haemacytometer and OD680 was investigated. The results showed that all the four irons had positive influence to growth and lipids accumulation, and the infection of Fe3+ was being prominent.(2) The effect of iron Fe3+ on growth and lipids accumulation in Phaeodactylum tricornutum,C. sorokiniana CS-01,Isocrydid galbana respectively by haemacytometer and OD68o was investigated. The results showed that Fe3+ had promoted the growth and lipids accumulation of this three microalgaes, and the infection of Fe3+ to C. sorokiniana CS-01 was in evidence.(3) The different expression of accD,rbcL and acc1 in microalgae exposed to different concentration of Fe3+ was studied. The result showed that accD had relationship with lipid accumulation, acc1 was concerned with some functionality compounds so the correlation between acc1 and lipid accumulation was not evident. rbcL had close relationship with growth.