Abstract:Analysis of fatty acids of Phaeodactylum tricornutum at different growth phases (exponential , the end of exponential, stationary and death phase) , indicated that the percentage of eicosapentaenoic acid (EPA) in total fatty acid peaked at the end of the exponential growth phase. The gene expression pattern of Δ5 desaturase at different growth phases of P. tricornutum was analyzed by Real-Time quantitative PCR. The results showed that it was most highly expressed at exponential growth phase . In order to study the effects of temperature on the growth and fatty acids composition in the microalgae . Phaeodactylum tricornutum was cultured in batch with varied temperatures .Its growth and fatty acids composition were examined. The results showed that the alga grows fast at higher temperatures than at the lower ones, the higher the temperature the faster the growth of the alga. The main fatty acids were C14:0、C16:0、C16:lΔ9、cl8:lΔ9、c18:2Δ9,12、 C20:5n3 (EPA).The percentile content of fatty acids increased first and then decreased to the highest.Microalgal cell which was cultured in 15℃ had the higher content EPA(25.71%).
