Abstract:
Protease is an enzyme that carries out the proteolysis of proteins. The global market for industrial
enzyme sales exceeds 3 billion dollars, and proteases account for around 60% of total sales. This class
of enzymes finds applications in waste treatment, bio-remediation processes, detergents and the leather
industry. However, the search for microbial sources of proteases is arousing the curiosity of researchers,
but fungal proteases remain the key tools of biotechnology and increasingly reflect the importance and
infinite role of molds in different applications, presenting many advantages such as: substrate
specificity, ease of genetic manipulation, stability under unfavorable conditions, separation of
mycelium by simple filtration. The aim of this research work is to characterize the crude extract of
fungal proteases in terms of temperature, PH, metal ions, substrate specificity, inhibitors and
surfactants. Filamentous fungi were isolated from soil samples taken from various locations in the
Adekar wilaya region of Bejaia. The strains identified and isolated were tested for their ability to
produce proteases, then various waste products such as wheat bran, soybean meal, poultry feathers,
orange peel and potato peel were tested by solid and submerged fermentation. Significant results were
achieved with wheat bran, poultry feather and potato peel. Preliminary tests, however, were carried out
on wheat bran, as the best yields were obtained with the latter. Experiments were carried out on two
fungal strains A05 et A22. Thanks to the results of the enzymatic extract characterization, we were able
to set a temperature of 45°C - 40°C respectively, and a pH of 7 for strain A05 and 12 for strain A22. Both
stimulating and non-stimulating effects were recorded at metal ion level for the strains. With regard to
substrate specificity, strong proteolytic activities were reported with casein for both filamentous fungi.
Positive and negative effects were observed for inhibitors and surfactants
