PROTEOLYTIC ENZYMES OF MYCELIAL FUNGI

Abstract

The literature and the original experimental data on the synthesis of proteolytic enzymes by mycelial fungi, properties and application of proteases were analyzed. The wide distribution of the ability to produce proteases was demonstrated among fungi of various genera. Fungal proteases are distinguished by substrate specificity and broad range of optimal values for substrate hydrolysis, pH-and thermal stability. The multiple application aspects of fungal proteases and their catalytic characteristics determine the commercial prospects of fungi as the industrial enzyme producers. K e y w o r d s : mycelial fungi-producers, proteolytic enzymes, properties, hydrolysis, application. Proteolytic enzymes affiliated to hydrolases catalyze reaction of protein hydrolysis to peptides or free amino acids. Proteases are involved in the normal physiological processes of protein and cellular peptide biogenesis in the living species and in abnormal pathological processes. They can be applied in diverse industries, medicine, agriculture and are indispensable as research tools. Proteases originating from plants (papain, bromeline) and animals (trypsin, chemotrypsin, pepsin, rennin) are well-known and thoroughly examined [47]. Microorganisms are the most attractive sources of proteolytic enzymes, hardly limited by scale of production. Proteolytic enzymes are synthesized by various microbial cultures-bacteria, yeasts, streptomycetes, fungi [7, 12, 20, 37, 40, 47]. Bacteria of genera Bacillus, Lactobacillus, Fervidobacterium, Pseudomonas, Microbacterium, Yersinia are recognized as producers of serine, cysteine and metal proteases, aminopeptidases [20, 47]. Bacteria of genus Bacillus are applied for industrial production of neutral and alkaline proteases. Representatives of genera Candida and Trichophyton synthesize aspartyl proteases, aminopeptidases, carboxypeptidases, dipeptidylpeptidases, Streptomyces-serine proteases [7, 37]. Mycelial fungi are the most promising cultures for large-scale manufacturing of proteolytic enzymes. They synthesize extracellular proteases belonging to various families and subfamilies, showing activity