Characterizing Fungal Decay of Beech Wood: Potential for Biotechnological Applications.

The biotechnological potential of nine decay fungi collected from stored beech logs at a pulp and paper factory yard in Northern Iran was investigated. Beech blocks exposed to the fungi in a laboratory decay test were used to study changes in cell wall chemistry using both wet chemistry and spectroscopic methods. Pleurotus ostreatus, P. pulmonarius, and Lentinus sajor-caju caused greater lignin breakdown compared to other white-rot fungi, which led to a 28% reduction in refining energy. Trametesversicolor caused the greatest glucan loss, while P. ostreatus and L. sajor-caju were associated with the lowest losses of this sugar. Fourier transform infrared spectroscopy (FTIR) analyses indicated that white-rot fungi caused greater lignin degradation in the cell walls via the oxidation aromatic rings, confirming the chemical analysis. The rate of cellulose and lignin degradation by the T.versicolor and Pleurotus species was high compared to the other decay fungi analyzed in this study. Based on the above information, we propose that, among the fungi tested, P. ostreatus (27.42% lignin loss and 1.58% cellulose loss) and L. sajor-caju (29.92% lignin loss and 5.95% cellulose loss) have the greatest potential for biopulping.

Comparison of the Decay Behavior of Two White-Rot Fungi in Relation to Wood Type and Exposure Conditions.

Fungal wood decay strategies are influenced by several factors, such as wood species, moisture content, and temperature. This study aims to evaluate wood degradation characteristics of spruce, beech, and oak after exposure to the white-rot fungi Pleurotusostreatus and Trametesversicolor. Both fungi caused high mass losses in beech wood, while spruce and oak wood were more resistant to decay. The moisture content values of the decayed wood correlated with the mass losses for all three wood species and incubation periods. Combined microscopic and chemical studies indicated that the two fungi differed in their decay behavior. While T. versicolor produced a decay pattern (cell wall erosion) typical of white-rot fungi in all wood species, P. ostreatus caused cell wall erosion in spruce and beech and soft-rot type I (cavity formation) decay in oak wood. These observations suggest that P. ostreatus may have the capacity to produce a wider range of enzymes/radicals triggered by the chemical composition of wood cell walls and/or local compositional variability within the cell wall.