Chestnut shell and barley bran as potential substrates for laccase production by Coriolopsis rigida under solid-state conditions

The potential of two lignocellulosic wastes chestnut shell and barley bran for laccase production by the white-rot fungus Coriolopsis rigida under solid-state conditions was assessed. These materials were selected due to their availability and low cost, since they are by-products of the food processing industries abundant in most countries. Barley bran gave the highest laccase activities, showing a maximum value of 3 · 105 nkat/L, which was around 25-fold higher than the value attained in the chestnut shell cultures. In addition, the ability to degrade three structurally different dyes (Indigo Carmine, Methyl Orange and Methyl Green) by the extracellular liquid from the barley bran copper-supplemented cultures (1 mM) was analysed. Nearly complete decolourization was obtained for the dyes Indigo Carmine and Methyl Green, whereas Methyl Orange showed more resistance to decolourization.