Sucrose-to-ethanol microalgae-based platform using seawater

(These authors contributed equally)


Highlights

• Bioprospecting for native sucrose-accumulating microalgal strains

• Induction of sucrose and lipid accumulation using seawater

• Mild sugar-extraction conditions and direct conversion into ethanol

• Modeled productivity of 4200 L ethanol·ha−1·year−1 in raceway ponds in Brazil

Abstract

Microalgal biomass is increasingly considered a promising feedstock for the production of bioethanol because it has simpler biochemical composition and structural features than plant feedstocks. However, it still requires hazardous and/or expensive acid or enzymatic saccharification processes before its conversion into ethanol by fermentation. To bypass this limitation, we identified microalgal strains that accumulate up to 10% (w/w) of sucrose, a readily fermentable sugar. Conditions were optimized to produce sucrose in half-strength seawater, as well as efficient extraction by very mild procedures, and conversion into ethanol. We present a model based on cultivation in environmental photobioreactors that predicted a productivity of 4200 L ethanol·ha−1·year−1 in raceway ponds in Brazil, approaching the average sucrose and ethanol productivity from sugarcane.

Keywords

  • Biofuels
  • Saccharification
  • Sugars
  • Bioethanol
  • Biorefinery
  • Water footprint
Publicación: Sucrose-to-ethanol microalgae-based platform using seawater