Fractionation and Bioconversion of Micro-Algae Into Bioethanol

Fractionation method for micro-algae using enzymes and microorganism was investigated. Micro-algae, Schizocytrium sp contain approximately 25% lipids, 20% carbohydrates, protein, ash etc. Due to its high Docosahexaenoic acid (DHA) content (~30% of lipids), Schizocytrium sp is currently used for DHA production in the US. In our method, bioethanol and lipids can be produced and recovered in liquid form and thus remaining solid has high protein content. During hydrolysis of micro-algae, lipid components can be obtained with no additional chemical extraction process in this method. Bioethanol production was achieved by enzyme hydrolysis followed by ethanol fermentation using Escherichia coli KO11.

In this work, the appropriate conditions for the productions of lipids (DHA), sugar monomers, and ethanol were explored. To assess the effectiveness of fractionation, the composition of lipids and remaining solids were examined.