Quantification and mitigation of byproduct formation by low-glycerol-producing Saccharomyces cerevisiae strains containing Calvin-cycle enzymes

Background: Anaerobic Saccharomyces cerevisiae cultures require glycerol formation to re-oxidize NADH formed in biosynthetic processes. Introduction of the Calvin-cycle enzymes phosphoribulokinase (PRK) and ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) has been shown to couple re-oxidation of biosynthetic NADH to ethanol...

Recovery of acetate by anion exchange with consecutive CO₂-expanded methanol desorption: A model-based approach

Production of bio-based acetate is commonly hindered by the high costs of the downstream processing. In this paper, a model is developed to describe a new method that recovers acetate salts using anion exchange resins, and subsequently desorbs and upgrades them using CO₂-expanded alcohol. The model consists of equilibrium...

A new laboratory evolution approach to select for constitutive acetic acid tolerance in Saccharomyces cerevisiae and identification of causal mutations

Background: Acetic acid, released during hydrolysis of lignocellulosic feedstocks for second generation bioethanol production, inhibits yeast growth and alcoholic fermentation. Yeast biomass generated in a propagation step that precedes ethanol production should therefore express a high and constitutive level of acetic acid tolerance before...