Abstract:

In order to get the strains of high-yielding cellulase, to alleviate the present bad situation: the activity of most cellulase is relatively low; the supply of cellulase has failed to keep pace with demand. Some higher cellulase-producing strain were picked from the nature and then carried them on mutation breeding under the UV light and 60 Co-γrays to obtained mutants of those high-produced. The original stains gained by screening had been preliminarily identified as the Actinomycete XZ-33 by observing the form of bacterial colony, mycelium and spores. According to the interrelation between the fatality rate, mutation doses and mutation rate ,it could be deduced that the most appropriate conditions of induced mutation is that exposing them under UV-irradiation for 7 minute and γ rays-irradiation up to 0.6KGy. After a series of mutation breeding a high cellulase-producing mutant stain have been obtained, named as mutant UV-Co16, its CMCase enzyme activity reached at the level of 66.15 IU/mL, and PFAase enzyme 2.91 IU/mL, it is respectively 3.17 times and 2.42 times higher than the original screened strains. The success to get a high cellulase-producing mutant stain laid the foundation of the technology that using special microorganism to ferment to produce ethanol.