Sequential proteolysis and cellulolytic hydrolysis of soybean hulls for oligopeptides and ethanol production

•Proteolysis of soybean hulls allowed removal of around 60% of proteins as small peptides.•Weak-acid pretreatment of deproteinized biomass released around 60% of hemicellulose.•Conversion (cellulose to glucose) of 55% was reached after 48–72h of cellulolytic hydrolysis.•Ethanol productivity for the integrated process was around 0.20g/L/h.