Extracellular laccase from <i>Pleurotus sajor-caju</i>: Fermentative conditions and influence of nitrogenous sources

Abstract

The present paper describes the production of extracellular laccase, a lignolytic enzyme, through fermentation of molasses salt medium (MSM) by <i>Pleurotus sajor-caju</i>, an edible mushroom, under stationary condition. MSM supported better growth of the fungus as well as laccase production compared to the other two media used, <i>viz</i>., whey and potato dextrose broth. Both laccase and edible biomass production attained the maximum value after 15 d of fermentation and depended on the fungal species, physico-chemical conditions of fermentation, and nature and composition of the fermentation media. Increase in laccase and biomass production to the extent of 9.1-48.0% and 4.2-76.4%, respectively was achieved by supplementing the medium with different organic and inorganic nitrogen sources. The positive effects of supplementation of MSM with nitrogen sources on enzyme production resulted from higher biomass yield. About 2.5-fold increase in laccase activity was obtained in comparison with the non-optimized medium. The results establish the importance of <i>P. sajor-caju</i> for the production of lignolytic extracellular enzyme, laccase.