Scale-up for esters production from straw whiskers for biofuel applications.

•Scale-up of anaerobic acidogenesis of wheat straw by a UASB culture.•The process was promoted by culture immobilization on kissiris.•Organic acids were produced from straw without a separate hydrolysis step.•1-Butanol was the best solvent for acids recovery from the fermentation broth.•Enzymatic esterification of the acids with 1-butanol resulted to 90% yield.