Induction of laccase activity in the edible straw mushroom, Volvariella volvacea.

Volvariella volvacea, strain V14, produces multiple forms of extracellular laccase when grown in submerged culture in a defined medium with glucose as sole carbon source, and on cotton waste 'compost' representative of the conditions used for industrial-scale mushroom cultivation. In liquid culture, enzyme synthesis is associated with the onset of secondary growth, and is positively regulated by copper (up to 200 microM CuSO(4)) and by various aromatic compounds. In solid-state systems, only low levels of laccase are detectable during the vegetative growth phase but enzyme activity increases sharply at the onset of fruiting and during sporophore development.