[Cloning of the Penicillium canescens endo-1,4-beta-glucanase gene egl3 and the characterization of the recombinant enzyme].

The gene egl3 of the filamentous fungus Penicillium canescens endo-1,4-beta-glucanase, belonging to family 12 glycosyl hydrolases, was cloned and sequenced. The gene was expressed in P. canescens under the control of the strong promoter of gene bgaS, coding for beta-galactosidase of this fungus, and efficient endoglucanase producer strains were obtained. The recombinant protein was isolated from the culture liquid of the producer strain EGL3-13 and purified to homogeneity; its specific activity was 31.7 IU; molecular weight, 26 kDa; and pH and temperature optimums, 3.2 and 54 degrees C, respectively. The Km and Vm values for CMC hydrolysis were determined; they amounted to 17.1 g/1 and 0.31 microM/(mg s), respectively.