There are many methods of determining the activity of cellulolytic enzymes and numerous ways of expressing this activity. Since, however, the remits obtained in different research centres are almost completely incomparable, an attempt has been made to introduce a uniform system for expressing a unit of enzyme activity. This system is based on the relationship between the degree of enzyme dilution and the enzyme activity.
The slope coefficient "a", determined experimentally, is constant for a given method of determining enzyme activities by reducing sugars irrespective of the substrate used, time of reaction or composition of cellulolytic complex.
The presented method of expressing activities of celhilases and hemicelhflases eliminates graphic descriptions which are very inconvenient in serial determination procedures.
The present paper describes a mathematical dependence which permits accurate determination of the activities of cellulolytic enzymes, irrespective of the substrate which they affect, and of the conditions applied for determining the activities.
Materials and Methods
Cellulolytic Enzymes
Different strains of moulds (Aspergillus, Trichoderma and Chaetomium) were cultivated in different media (Pyd, et al. 1977;Siwifiska and Galas 1977 ;Mandels and Weber 1969) under optimum conditions for each strain. The culture filtrates were treated as initial enzyme solutions with A 0 activities or were diluted (1-5,000 times)with 0.025 M acetate buffer, pH 4.6, resulting in enzyme solutions with A activities.