Polysaccharide cytochemistry in maturing Aspergillus flavus sclerotia

Polysaccharide content and the dynamics of its accumulation was studied during sclerotial growth and differentiation in Aspergillus flavus. Using cytochemical methods and enzymic digestion with α-amylase on ultrathin sections, it was confirmed that glycogen represented the main polysaccharide storage material. During sclerotial development glycogen progressively accumulated in the cytoplasm in the form of α- and β-particles, while in the vacuolar system it appeared only as β-particles. In mature sclerotia most of the glycogen was found in the cytoplasmic rather than the vacuolar form and it is therefore suggested that the cytoplasmic form of glycogen is the main storage polysaccharide accumulated for survival and germination.