Renewable culture of microalgae Isochrysis Galbana

This aim of this paper is to research on culturing marine algae with high efficiency. Using microalgae Isochrysis Galbana as a model organism, a rapid growth regularity of microalgae in 4.5-L bioreactor was discovered under optimized culture condition, namely, specific growth rates of microalgae from the fourth day to the seventh day at maximum phase (631~905×10⁴ cells·mL^-1·day^-1). Accordingly, a renewable model of culture microalgae was proposed, namely, at the end of exponential growth, microalgae of 2-L was taken from the bioreactor of 4.5-L, and then sterile natural seawater (SNSW) of 2-L was added into the bioreactor with remaining microalgae of 2-L, now microalgae density was approximately 1800 × 10⁴ cells/mL, with which Isochrysis Galbana will grow under maximum specific growth rate. After two days, density of microalgae reached to 4000 × 10⁴ cells/mL. We repeated the culture process of 2 day three times. Compared with the traditional model of culture microalgae, more than 42% microalgae biomass in per day was obtained in a 4.5-L bioreactor through the renewable culture. Here the renewable model of culture microalgae offered great potential for supplying raw materials of microalgae bioenergy.