By Safa Abd El-Kader Mohamed Hamed, Maisa Mohamed Ali Mansour
The current study aims to elucidate and compare ultrastructure alterations that occurred in larch wood
(Larix decidua Mill.) and beech wood (Fagus sylvatica) which were artificially infested with the selected fungi;
Aspergillus niger, Pencillium chrysogenum, Chaetomium globosum, (soft-rot fungi) Trichoderma viride and
Alternaria alternata (surface mold). Environmental scanning electron microscope were utilized to examine the
wood samples which were left three years. Microscopic examination showed differences in the patterns and
mechanism of decay in the two wood species and cell types invaded by the selected fungi. A. nigar and P.
chrysogenum can cause wood degradation more aggressively than C. globosum. Surface mold fungi, e.g. T.
viride and A. alternata may cause alterations in wood ultrastructurally like soft-rot fungi. The results of this
study encourage adding stain fungi and surface mold to wood destroying fungi classification, also
recommending examination their enzymatic system.