Strategies for utilisation of food-processing wastes to produce lipases in solid-state cultures of Rhizopus oryzae

The aim of the present study was to investigate the feasibility of several food-processing wastes as support substrate for lipolytic enzymes production by the fungus Rhizopus oryzae under solid-state conditions. Different experiments were conducted to select the variables that allow obtaining high levels of lipolytic enzyme activity. In particular, the use of inert and non-inert solid materials and lipidic and surfactant compounds was evaluated. It was observed that the addition of Triton X-100 together with barley bran involved lipolytic production values tenfold higher than the cultures exclusively grown on an inert support. In addition, from preliminary thermoinactivation kinetics studies, it was concluded that the strategy proposed in this investigation entails another benefit in terms of resistance of the produced enzymes against thermoinactivation.