Optimising microalgae-derived butanol yield

Abstract

Rapid global urbanisation emphasises the necessity to explore sustainable energy resources to fulfill escalating energy demands. Biobutanol emerges as a promising biofuel due to heightened energy density and molecular similarity to petrol. Microalgae, rich in carbohydrates, offer a potential glucose source for biobutanol fermentation. The current study shows that varying CO2 concentrations affect carbohydrate content in the biomass of P. kessleri bh-2 and Scenedesmus sp.k-7. The introduction of 1% CO2 significantly improved carbohydrate productivity, reaching 74.5% for P. kessleribh-2 and 71.0% for Scenedesmus sp.k-7. Enzymatic hydrolysis was found to be most effective for ABE fermentation, with optimal results obtained at enzyme loads of 8 mg g−1 cellulase and 2 mg g−1 amylase for both strains. When C. acetobutylicum cells were cultivated with pretreated P. kessleribh-2 biomass, the biobutanol yield amounted to 4.8 gL-1 at a glucose concentration of 5.30 gL-1, demonstrating strain's superior performance compared to Scenedesmus sp.k-7.