PRODUCTION OF VOLATILE FATTY ACIDS FROM CHEESE WHEY WITH IMMOBILIZED CELLS Extended abstract

Dairy industry is practised all over the world for the production of milk, butter, yogurt, ice cream, cheese, and other milk derivates. This activity generates big amounts of highly COD containing effluents. Since their disposal requires a treatment step in dedicated plants aimed at abating the wastes organic content, their valorization within biorefinery schemes represents a valuable opportunity. In that frame, there is a strong interest on producing volatile fatty acids (VFAs) for the subsequent biotechnological production of biopolymers (namely, polyhydroxyalkanoates (PHAs)). Some investigations, which employed cheese whey (CW) as the PHA process feedstock, were reported in the literature (Pais et al., 2009). Such a waste is one of the dairy industry effluents exerting higher organic contamination, mainly due to its high lactose content. Thus, it represents a good raw material candidate for biorefinery processes. Few experiences about CW anaerobic acidogenic digestion for the production of ethanol and lactic acid with immobilized cells by employing a membrane bioreactor or packed-bed column were already described (Kosseva et al., 2009). However, almost no experiments for VFAs production with immobilization, from CW, have been reported.