Bioethanol production via different saccharification strategies from H-tetrachotoma ME03 grown at various concentrations of municipal wastewater in a flat-photobioreactor

Biodiesel and bioethanol are currently the biofuels with the largest production scales. This study was aimed to evaluate feasibility of Hindakia tetrachotoma ME03 grown at various concentrations (0%, 25%, 50%, 75% and 100%) of wastewater as a potential biomass feedstock to produce bioethanol in a flat-photobioreactor. In addition, we examined the different hydrolysis strategies such as acidic, alkaline, and enzymatic hydrolysis for saccharification of microalgal biomass and optimized fermentation process via Saccharomyces cerevisiae. The results revealed that maximum bioethanol content and percent yield of H. tetrachotoma ME03 were 11.2 +/- 0.3 g L-1 and 94 +/- 2.2%, respectively, after fermentation of S. cerevisiae at 36 h in 50% of wastewater. Enzymatic hydrolysis with beta-glucosidase/cellulase + alpha-amylase had the highest amounts of saccharification with 92.3 +/- 0.9%. These findings indicate H. tetrachotoma ME03 grown in wastewater can be a promising candidate for bioethanol production after bacterial and fungal contamination problems are solved via filtration technologies.