Growth Characteristic of the Oleaginous Mi-croalga <i>Chlorella ellipsoidea</i> SD-0701 with Lipid Accumulation

Abstract

Microalgae have great advantages as a new biomass source for fuel production. But microalgae are photosynthetic microorganisms, which normally grow in the light. Because of this growth condition, the commercial viability of microalgal biofuel is limited by current production systems. To obtain microalgal biofuel, fermentation is a more convenient, more economical and practical industry model. In this study, we asked whether and why the dark fermentation of C. ellipsoidea SD-0701 could be achieved by changing the culture medium formula. We focused the research on carbon-containing compounds and the initial pH of media. The results indicated that glucose was the optimum carbon-containing compound, which provided C. ellipsoidea SD-0701 with energy and carbon skeleton for accumulating organic compounds including lipids. When C. ellipsoidea SD-0701 was cultivated in the add-nutrition medium containing glucose, the optimum initial pH for the growth of C. ellipsoidea SD-0701 was pH 7.71. Therefore, if the suitable medium is used, C. ellipsoidea SD-0701 can grow normally in the dark, which is the same condition as the fermenter, and high microalgal biomass (0.50 g&middotL -1 ) and lipid yield (232.90 mg&middotL -1 ) can be achieved.