Studies on fungal lipase production for biological pitch control

Biological pitch control in the pulp and paper manufacturing is a biotechnological approach that has recently been developed, in order to obviate the troublesome pitch by hydrolysing the wood extractives present in the resins. Fungal lipases are an efficient tool for reduction of pitch, which can be used either directly to hydrolyze the triglycerides after chemical or mechanical pulping, or by inoculating wood chips with lipolytic fungi. This work was undertaken to select lipolytic fungal strains to be applied during the pulp and paper processing, and to optimize lipase production. In order to determine the best lipase producers, a screening was carried out with several fungal strains belonging to our collection, and that have been used in earlier studies concerning lignocellulosic materials biodegradation. Four different methods were tested and compared in order to select a rapid assay to detect lipase activity, using either mycelial plugs or fungal extracts. Production of extracellular lipase by the selected strains on olive oil medium was studied and compared.