Exploration of fungal spores as a possible storehouse of proteolytic biocatalysts

Abstract

Studies were carried out to define the relation between enzyme production and fungal sporulation, in solid-state cultivation conditions of the filamentous fungus Aspergillus oryzae NRRL 2217 to get information on possible links between metabolite synthesis and differentiation phenomena. The efforts taken to explore the possibility for the presence of a neutral protease inside the spores of this fungus was to increase the overall enzyme yield. Results showed that the production of enzyme (neutral protease) and biomass (total protein) were synchronised, both reaching their respective maximum levels at 48 h of fermentation, and decreasing thereafter. Neutral protease synthesis was not related to sporulation. The spores produced were subjected to various permeabilisation procedures, and the increase in the levels of neutral protease was monitored. Mechanical shear was the sole technique that was able to disrupt spores but even this failed to increase enzyme titres, confirming the absence of intra-spore proteases.