[Localization of ribonucleases in the mycelium of the fungus Aspergillus clavatus].

The localization of ribonucleases in Aspergillus clavatus mycelium was studied using differential centrifugation of mycelial homogenates, preparation of protoplasts, by cytochemical and immunochemical studies. The RNase activity was represented mainly by guanylic and nonspecific RNases and was not associated with the intracellular structures. The cytochemical and immunochemical observations revealed the presence of a nonspecific RNase activity in the periplasm, mitochondria, perinuclear space and vesicular structures. The presence of this RNase in the periplasmic space and vesicular structures of A. clavatus suggests that it may be secreted through a fusion of the vesicular membranes with the cytoplasmic membrane, and then from the periplasm through the cell wall into the surrounding medium.