Evaluation of fungal endophytes for lignocellulolytic enzyme production and wood biodegradation

Wood-inhabiting fungal endophytes of Chilean tree species Drimys winteri and Prumnopitys andina were isolated and assayed for lignocellulolytic enzymes production and wood biodegradation. Using an increment wood borer, four endophyte fungi were isolated: in D. winteri a basidiomycete identified as Bjerkandera sp., and a Deuteromycete classified as Mycelia sterilia (Dw-2), whilst in P. andina an unidentified Basidiomycete (Pa-1) and also a M. sterilia (Pa-2) were found. In agar solid media, the Basidiomycetes displayed positive reaction to phenoloxidase (PO) and cellulase, and did not show iron-reducing activity. A weak reaction to the cellulase and iron-reducing assay but not for PO activity was detected in both M. sterilia isolates. PO activity was detected in liquid cultures of both basidiomycetes. After treating D. winteri wood chips with Bjerkandera sp. presented the following weight and component losses: weight of 13.3 +/- 1.5%, total lignin of 13.2 +/- 1.2%, glucan 16.9 +/- 4.4%, polyoses 22.6 +/- 3.8% and extractives 16.0 +/- 1.7%. For Pa-I. weight and component losses were: weight of 5.6 +/- 0.0%, total lignin of 8.0 +/- 0.6%, glucan 7.0 +/- 0.3%, polyoses 9.0 +/- 0.5% and extractives 7.7 +/- 0.1 % in 45 days were detected. These results indicate that isolated fungal basidiomycete endophytes are able to develop a non-selective white-rot wood decay pattern. (C) 2006 Published by Elsevier Ltd.