Use of ligninolytic mushrooms for bioremediation

Several studies regarding bioremediation by means of fungi and their enzymes have been performed in the Institute of Agro-Environmental & Forest Biology (CNR) for many years. The ligninolytic mushrooms resulted active in applications for soil decontamination and wastewater treatment, producing degradation of phenols, oxytetracycline [1] and polycyclic aromatic hydrocarbons (PAHs). In particular the bioaugmentation technique was applied with the addition of mycelium for the treatment of Olive Mill Wastes, with a strong reduction of phenols and the production of fungal biomass, useful for the extraction of high added value compounds like glucans and chitin [2]. Pleurotus ostreatus ability in PAHs degradation was tested utilizing a creosote contaminated soil and creosote-treated wood (sleepers). Results showed a good PAHs degradation in both cases [3, 4]. Ligninolytic mushrooms are known to produce the enzymes laccases both in the presence of lignocellulosic substrates and constitutively, in some phases of their life cycle. Since laccases are extracellularly produced, their purification is simple and cheap. They can be particularly suitable for biotechnological applications, because their thermal stability and resistance to pH and chemical agents can be increased immobilizing them on solid supports. A new laccase based biocatalyst supported on a natural clinoptilolite was prepared in IBAF, which resulted efficient in chlorophenols removal [5].