Reutilisation of food processing wastes for production of relevant metabolites: application to laccase production by Trametes hirsuta

The aim of the present study was to investigate the feasibility of kiwi fruit wastes as a support-substrate for laccase production by the white-rot fungus Trametes hirsuta under solid-state conditions. Different experiments were conducted in order to select the variables that allow obtaining high levels of laccase activity. In particular, the effect of the initial ammonium concentration, the amount of support employed, the need for pre-treating the support and the part of kiwi fruit wastes utilised (peelings or peelings plus pulp) was evaluated. The highest laccase value (around 90,000 nkat/l) was obtained operating at an initial ammonium concentration of 0.150 g/l and with 2.5 g of pre-treated peelings of kiwi fruit. This activity is higher than that reported to date with no inducers addition. These promising results open the way for the value-added utilisation of other similar food processing wastes.