Abstract:

This research was to prove whether there is some special protein in cellulaseproducing microorganism acting as a cellulaseactivityenhancing protein，thus exploring its potential application in lignocellulose hydrolysis.An extracellular protein without cellulase activity was separated and purified from culture medium of Trichoderma Koningii through a series of procedures, including ultrafiltration, ammonium sulfate precipitation, octylSepharose CL4B and Sephadex G75 column chromatographyThe molecular weight of the prtotein was estimated to be 30×103 by SDS-PAGEWith the addition of this protein(400μg per g filter paper）into the reaction mixture containing filter paper and cellulase(0.06 IU per g filter paper ), the reducing sugar released during 48 h was observed to increase greatly, 1049% greater than that of the control hydrolysisMoreover, it was found that this purified protein enhanced the activity of exoglucanase, one of the three components of fungi cellulase, while endoglucanase and β-glucosidase activities did not change muchMass spectrometry analysis indicated that this purified protein was an unknown proteinBased on these results, this purified extracellular protein originated from Trichoderma Koningii could be regarded as a cellulase activityenhancing protein, which was different from the reported plant expansin and swollenin.