[Non-steady state kinetics for action of a multienzyme cellulase system toward insoluble cellulose].

A kinetic theory for multienzyme cellulase systems in non-steady state conditions (in relation to intermediate metabolites) of hydrolysis of insoluble cellulose has been developed. To verify the kinetic regularities obtained the action of 12 different cellulases from the fungi Trichoderma, Geotrichum and Aspergillus as well as from bacterial cells Thermomonospora sp. and Rapidase preparation has been studied with respect to ball milled cotton linters and microcrystalline cellulose. The experimental data were discussed in the framework of mechanism of enzymatic hydrolysis of cellulose suggest by us recently and the main routes for glucose and cellobiose formation from insoluble cellulose have been elucidated. The effects of concentrations of cellulase preparations and the initial substrate on (i) time lags for glucose formation, (ii) stationary rate of glucose formation, and (iii) kinetics of cellulose conversion to glucose at low and high conversion degrees, were studied. A theoretical analysis of maxima and inflection points on the kinetic curves for intermediates (oligosaccharides and cellobiose) was performed. The effects and intensity of stirring on the time lag values for glucose formation were studied and the relative role of kinetic and diffusional factors in this process was evaluated. The data obtained are unequivocally indicative of the common mechanism of conversion of cellulose to glucose by cellulase complexes irrespective of their source and composition.