Observations on the cell-wall compositions of the bracket fungi Laetiporus sulphureus and Piptoporus betulinus

Homogenized tissues and their alkali-soluble and alkali-insoluble fractions of fruiting bodies of the basidiomycetes Laetiporus sulphureus and Piptoporus betulinus were investigated using X-ray diffraction, infrared spectrometry and chemical methods. The presence of (13)--d-glucan, (13)--d-glucan and chitin was established. The relative amounts of these polysaccharides were different in the two species and differences were also found between context and trama. The proportion of (13)--d-glucan was exceptionally high in the context of L. sulphureus (about 78%). In addition, the trama of both species contained a substance resembling a cyclic wax by its X-ray pattern and solubility properties. The substances identified are considered to belong to the hyphal wall