Study On Key Genes Of Beta-Glucosidase From Penicillium Betulinum

Cellulase system can be divided into circumscribed-?-1,4-glucanase,cut inside-?-1,4-glucanase and ?-glycosidase enzymes,including ? glycosidase enzymes is generally low in cellulose enzyme hydrolysis of the main causes of low efficiency,and ? glycosidase enzymes produced by the hydrolysis of cellulose fiber oligosaccharides and cellobiose and feedback inhibition enzyme and enzyme hydrolysis activity,further the ability to inhibit the hydrolysis of cellulose.We propose to improve the hydrolysis efficiency of the whole hydrolytic system by increasing the activity of ?-glucosidase.In order to improve the activity of ?-glycosidase enzymes,we must clarify the role of key genes of ?-glucosidase,thus laying the foundation for further improving the hydrolysis efficiency of cellulase system.Penicillium cypress is a kind of lignocellulosic degrading bacteria,which can metabolize cellulose hydrolysates quickly.The common biological method is to modify penicillium cyclamate by genetic engineering,so as to improve its lignocellulose degradation ability and increase its cellulase production.In this study,the function of the key genes of ?-glucosidase in penicillium cynanensis was studied,thus laying a foundation for the next genetic modification.The results showed that the activity of ?-glucosidase and filter paper enzyme of over-expressed Peng 1582 accounted for 50.57%and 38.43%of the control strain,respectively;The ?-glucosidase and filter paper enzyme activities of Peng 3441 accounted for 85.06%and 70.86%of the control strains,respectively;The ?-glucosidase and filter paper enzyme activities of Peng 1797 were only 50.59%and 19.12%of those of the control strain,respectively;The ?-glucosidase activity and filter paper enzyme activity of Peng 2535 mutant strain were 1.17 and 3.05 times of the control strain respectively.Two knock-out Mutants Peng 1797 and Peng 3441 were obtained.The results showed that the activity of ?-glucosidase of the mutant strain Peng 1797 was 59.85%higher than that of the control strain 9-3,the activity of exonucleotide enzyme was 62.76%higher,and the activity of filter paper was 24.17%higher.Initial speculation is that the gene is a negative regulatory transcription factor of ?-glucosidase.