Abstract: | The enzymic degradation of cellulose from Valonia macrophysa was observed by electron microscopy and evaluated by electron diffraction. Two types of Valonia samples were subjected to digestion; firstly, intact fragments cut from cell wall material and, secondly, cellulose microcrystals resulting from the acid hydrolysis of entire vesicles. These two substrates, when subjected to the action of crude cellulase complexes either from Trichoderma reesei or Schizophyllum commune were readily degraded. During the degradation, each microfibril or microcrystal became fibrillated into longitudinal crystalline sub-elements having widths ranging from below 2 nm to the full size of the initial Valonia microfibrillar width. These observations are evaluated in term of current theories concerning the topological action of cellulases. |