Alga-Based Biodiesel Production and Optimization Using Sugar Cane as the Feedstock

The alga Chlorella protothecoides is known to produce oil suitable for biodiesel preparation by heterotrophic cultivation in media containing glucose as a carbon source. In this study, sugar cane juice was used as alternative carbon supply for oil production. As a result, the highest oil content of 53.0% by cell dry weight was achieved. Fermentation in a 5 L bioreactor showed that algae using sugar cane juice hydrolysate (SCH) grow faster thin) that using glucose. Conversion ratios of sugar/biomass and sugar/oil using SCH were 15.2 and 8.8% higher than that using glucose, respectively. Biodiesel prepared from algal oil by transesterification is mainly composed of 9-octadecenoic acid methyl ester, 9,12-octadecadienoic acid methyl ester, and hexadecenoic acid methyl ester. Our results suggest that sugar cane is a good feedstock for biodiesel production. Response surface methodology upon exploring the effect of C/N and concentration of yeast extraction (YE) on the yield of biomass and oil was performed. The optimal production with the highest output-cost coefficient of 0.061 +/- 0.004 was achieved when C/N was 26.9 and YE was 0.60 g L-1.