BACKGROUNDThe final prices of fermentative culture broths must be reduced in order to extend biotechnological processes to an industrial scale. In this way, residual lees from the beer, cider and wine industries were evaluated as a source of nitrogen and micronutrients for xylitol production by Debaryomyces hansenii. RESULTSThe liquid fraction of wine or beer lees was employed as suitable culture media for xylitol production (Q(P) = 0.30-0.24 g L-1 h(-1), respectively). Complete beer lees diluted to 25% produced 27.2 g L-1 after 168 h (Q(P) = 0.16 g L-1 h(-1)). Autolysis of beer lees produced 15.6 g L-1 of xylitol using whole lees (Q(P) = 0.11 g L-1 h(-1)), or 34.8 g L-1 using the solid fraction (Q(P) = 0.36 g L-1 h(-1)). The specific xylitol productivity (0.12 g g(-1) h(-1)) achieved with the solid fraction was even higher than that obtained with the synthetic control (q(P) = 0.074 g g(-1) h(-1)). CONCLUSIONSResidual lees can be used as economical nutrients. In some cases, autolysis treatments are necessary to increase the amount of available nitrogen thus improving the fermentative parameters. (c) 2014 Society of Chemical Industry