Enhancing Downstream Processing Of Algal-Based Biofuel Using Novel Fused Bacteria And Green Solvents

Abstract

The present study investigated the utilization of algal biomass to produce bio-oil and acetone, butanol, and ethanol (ABE) products. Novel Clostridia fusants (C. beijernickii + C. thermocellum-CbCt and C. acetobutylicum + C. thermocellocum-CaCt) were developed using protoplast fusion technique and subsequently subjected to UV radiation for strain enhancement. Resultant mutated fusants showed improvement in thermal stability and higher resistance to biobutanol toxicity. Algal biomass was initially subjected to various hydrolysis treatments prior to fermentation. Combination treatment of thermal, chemical, and enzymatic resulted in maximum sugar release of 27.78 g/L. Maximum biobutanol concentration from fermentation using CbCt resulted in 7.98 g/L. Fermentation using CaCt produced a concentration of 7.39 g/L. Oil extraction from virgin algae investigated a green, bio-based approach using terpenes with ultrasonication and a modified, Bligh and Dyer method, separately. Combination method, ultrasonication followed by the modified Bligh and Dyer, resulted in oil yield of 46.27% (dlimonene) and 39.85% (p-cymene). Oil extraction was also produced from an algae sample following fermentation. Combined extraction method using fermentation sample resulted in oil yield of 65.04%.