Screening Strains For High Efficiently Degrading Cellulose And Ion Implantation Research

Cellulose is the most abundant organic material on the earth,and half of the world's annual production of organic material is cellulosic materials,but it's very difficult to be hydrolyzed and used.Only a small part of them have been used and the vast majority have been disposed,how to more effectively use cellulose resources has become a hot topic in today's world.Most of the cellulose materials are degradated by the microorganism in nature,So it's an important way to use cellulose in the future by screening and artificial transformating strains for degrading cellulose.In this study, cellulose degradation fungus have been screened from different materials,and high efficient degradation cellulose mutant has been gotten by low-energy ion implantating.It is analysized the molecular change of CBH gene for the mutant strain. The main experimental results are as follows:1.Six cellulose degradation strains have been found from fuye in the soil,sewerage in the paper mills and decaying wood.Through comparison the relative activity enzyme,an high efficient degradation cellulose strain named 280TS have been obtained at last.Through observation of 280TS morpHologic and identification of ITS sequence,we identify it as Penicillium.2.After optimizing the single factor of The cellulose degradation strain of 280TS,it is found that the optimum temperature is 30℃,the suitable pH is 6.0 and the peak of fermentation time is 120 hours.3.Use low-energy ions Ar⁺ to implantate Spores,and study the survival rate and mutation rate of cellulose degradation capacity.The result shows that the appropriate implantation dose is 2.08×10¹⁵ Ar⁺/cm² when the Implantation energy is4.Finally a high efficient degradation cellulose mutant has been gotten by low energy ion implantation aider two rounds of radiation andscreening,the results show that the genetic performance of the mutant is stable,and the activity of mutant CMC increased 3.4 times and FPA increased 4.3 times.5.Amplified cbhâ…¡gene by RT-PCR.After analysied by Blast,The result shows that it has over 80%homologenization with cbhâ…¡gene of Trichoderma viride.Through the comparison of cbhâ…¡gene between the mutant strain and the original strain,it has been found that six changes and four differences in its amino acid sequence.This result provides a molecular basis for the further study on the change of degradation cellulose strain.