A. Tsuneda et Rg. Thorn, INTERACTIONS OF WOOD DECAY FUNGI WITH OTHER MICROORGANISMS, WITH EMPHASIS ON THE DEGRADATION OF CELL-WALLS, Canadian journal of botany, 73, 1995, pp. 1325-1333
Interactions of two wood decay fungi, Lentinula edodes and Pleurotus o
streatus, with other wood inhabiting microorganisms were investigated
on agar and in fagaceous wood, primarily by scanning electron microsco
py. Micromorphologically, there were two principal modes of cell wall
degradation: (i) selective removal of amorphous wall components, follo
wed by the degradation of skeletal microfibrils, and (ii) simultaneous
degradation of all wail components. These two modes were observed in
three different degradation systems: (i) sapwood wall degradation by t
he wood decay fungi, (ii) hyphal wall degradation by mycoparasitic Tri
choderma, and (iii) hyphal wall degradation by pathogenic bacteria. Th
e simultaneous-type wall degradation in the systems i and ii was usual
ly caused by hyphal tips. In addition to the three systems, bacterioly
sis by the wood decay fungi was also studied. The bacterial cell walls
, as well as microfibril bundles of wood cellulose and fungal chitin,
were all fragmented into minute granules at later stages of microbial
degradation and the granules were further degraded into smaller units.
Frequency of occurrence and strength of mycoparasitic activity of Tri
choderma harzianum were influenced by the degree of wood decay where t
he interaction occurred. Presence of both cellulose and chitin microfi
brils apparently enhanced the mycoparasitic activity. In Quercus wood,
P. ostreatus showed a unidirectional growth toward bacterial colonies
, which formed as the result of decomposition of dead nematodes, and c
onsumed the unidentified bacteria. In nitrogen-deficient wood, fungal
and bacterial cell walls may serve as an important reservoir of nitrog
en for wood inhabiting microorganisms.