Litter-decomposing Fungi Research Articles

A green pigment similar to the pg fraction of P type humic acids and related compounds produced by litter-decomposing fungi

Abstract The coloring matter of fruiting bodies which were formed by wood-decomposing fungi (Ascoroycetes, Xylariaceae) was investigated. Alkali-soluble green pigments showing absorption spectra similar to that of Pg were obtained from the fruiting bodies of three species, Hypoxylon annulatum, Hypoxylon sp., and one unidentified fungus. Alkali-insoluble perylene-quinones were detected in all the fruiting bodies examined. The organisms most likely to produce Pg and/or its precursor were selected from the viewpoint of the chemical nature of the pigments and the ecology of the organisms. It was concluded that a mycorrhiza former (Cenoccocum graniforme), and five litter decomposers (Alternaria tenius, Aureobasidium pullulans, Hypoxylon annulatum, and two others) were producers of Pg and/or its precursor. On the other hand, Elsinoe sp., Cercosporina sp., and Cladosporium sp. which are parasites and whose pigments were found to be chemically different from Pg, were not considered to be main producers of the Pg ...

On the use of mycelium suspensions for substrate inoculation in studies of fungus growth

In investigations on fungi incapable of producing spores, conidia, or oidia under laboratory conditions the liquid media used for growth experiments are, according to the ordinary technique, inoculated with mycelium bits cut from colonies of the fungi grown on solid agar media in tubes or Petri dishes. The difficulties and disadvantages met with in employing this method are discussed. A new method is described using mycelial suspensions for inoculation of liquid substrates. The suspensions are prepared by shaking bits of mycelial mats with glass beads, about 6 mm in diameter, and distilled water or “physiological” salt solution under sterile conditions. The large mycelial particles are allowed to settle. The supernatant suspension is pipetted into a sterile flask and diluted to the propervolume. The suspended particles may be washed by sedimenting in a centrifuge, resuspending in distilled water or salt solution, and recentrifuging under sterile conditions. Of course the method may be modified in different ways. The new method is now used on a routine scale in this institute in investigations on mycorrhiza-forming and litter-decomposing fungi.