Cellulose content decreased in both substrates 9.6% for ES
and 14.3% for Populus sawdust. On the other hand, hemicellolose
increased for ES 23.6% but decreased for PS 41.04%. Lignin content
decreased in both treated substrates 48.3% for ES and 34.18% for PS.
This values were lower compared with those obtained with other
species. Nazareth and Sampy (2003) reported that the decrease in
lignin and cellulose content of hardwood sawdust by Panus tigrinus
(=L. tigrinus) after a 4-month incubation period was 56% and 64%,
respectively, while, in Lechner and Papinutti(2006),the decrease of
lignin and cellulose content in wheat straw was 21.49% and 53.26%,
respectively, in a similar period of time for the same species.
We observed that when G. pampeanus was grown on PS, the
holocellulose content drastically diminished (55%) showing the
preference of the mushroom for this compound in this substrate.
On the other hand, for ES, the holocellulose increased (13.98%) but
lignin content decreased 48.3%; thus results showed that when
G. pampeanus grows on Populus it prefers to degrade holocellulose,
meanwhile when it grows on Eucalyptus, it prefers to degrade
lignin. Lignin breakdown by white rot fungi is performed by a complex
panel of oxidizes such as phenol oxidase, the production and
activity of all these enzymes is physiologically coordinated (Cullen
and Kersten, 2004)