Zurbriggen B D, Penttilä M E, Viikari L, Bailey M J
VTT, Biotechnical Laboratory, Espoo, Finland.
J Biotechnol. 1991 Feb;17(2):133-46. doi: 10.1016/0168-1656(91)90004-f.
Endo-beta-glucanase I (EGI) of Trichoderma reesei was produced in laboratory and pilot scale using recombinant strains of "bottom-fermenting" Saccharomyces cerevisiae. The gene eg/1 was integrated in the chromosome or an expression cassette was inserted on a multicopy plasmid. Expression levels were compared in a laboratory scale bioreactor. The best EGI-producing strain was cultivated in pilot scale. Adsorbent treatment was used to remove endogenous yeast proteins and other impurities from the culture filtrate during concentration. Effective pilot scale one-step purification of the EGI protein was obtained using DEAE-Sepharose, on which EGI was weakly bound. The purified enzyme reacted with antibodies prepared against T. reesei EGI and catalyzed the hydrolysis of both insoluble and soluble substrates.