Cheese whey exploitation in a biorefinery manner is proposed involving anaerobic acidogenesis by a UASB mixed anaerobic culture and alcoholic fermentation by kefir. Both cultures were immobilized on gamma-alumina. The produced organic acids (0As) and ethanol could be esterified to obtain a novel ester based biofuel similar to biodiesel. During acidogenesis, lactic acid-type fermentation occurred leading to 12 gL(-1) total 0As and 0.2 gL(-1) ethanol. The fermented substrate was subsequently supplied to a second bioreactor with immobilized kefir, which increased the OAs content (15 gL(-1)), especially lactic acid, and slightly the ethanol concentration (03-0.4 gL(-1)). To further increase ethanol concentration, a second experiment was conducted supplying whey firstly to the immobilized kefir bioreactor and then pumping the effluent into the acidogenesis bioreactor, resulting in 40% increase of OAs and 10-fold higher ethanol content. The residual sugar was,,50% of the initial whey lactose; consequently, future research could result to further increase of ethanol and OAs. (C) 2017 Elsevier Ltd. All rights reserved.