Trichoderma And Aspergillus Niger With High Yield Fiber Decomposition Enzyme By Mutagenesis And The Optimization Of Fermentation Process

There is a bid gap in China is energy resources,with the annual corn import volume reaching 3.3 million tons in 2016.Straw production is rich,containing a lot of potential energy value.But the content of straw fiber is high,which is not easy to be digested and used by animals.1.The high-yielding fibrinolytic enzyme strains were screened out by the DNS enzyme activity measurement and corundum culture medium method of maize straw for 7strains of fungus,providing references for the efficient screening.2.The screen of trichoderma strains and aspergillus Niger to mutagenesis breeding,preservation of bacteria(laboratory)(uv,diethyl sulfate and diethyl sulfate compound mutagenesis)to obtain high cellulose decomposition enzyme mutation of bacteria,and the enzyme production ability of fermentation conditions and the hydrolysis of straw were studied.(1)mucor and aspergillus Niger were screened out by combined mutation of ultraviolet,diethyl sulfate and diethyl sulfate.Compared with the original bacteria,the uh-1xylanase of candida kongens increased by 42.7% and the cellulase by 78.5%.Aspergillus Niger x1u4-1 filter paper enzyme increased 66.7%.(2)Kang Shimu mildew UH-1 the optimal amount of solid-state fermentation conditions for ammonium sulfate added 2%,the quantity of 1.1 ml 84 h,water content of67%,fermentation time,under the condition of the filter paper enzyme activity reached0.86 U/g,cellulose enzyme activity 99.81 U/g,xylanase live 1150.32 U/g.Aspergillus Niger X1U4-1 the optimal solid-state fermentation conditions for the fermentation time of72 h,corn cobs,bran = 3:7,quantity of 1.2 ml,ammonium sulphate 4%,under the condition of the filter paper enzyme activity reached 0.77 U/g 93.8 U/g,cellulose enzyme,acid protease 4727.4 U/g,xylanase live 9383.18 U/g.(3)studies on the ability of mutant bacteria to hydrolyze straw indicate that the reducing sugar content of aspergillus Niger x1u4-1 increases by 6.8% at 12 h,while the glycosidase of micron-glucoside increases by 22.3%.The extracorporeal glucosaminase of e.coli uh-1 was increased by 71.8%,and the amount of reducing sugar was increased by67.8% at 12 h.The results showed that the complex mutagenesis could improve the enzyme production performance and straw hydrolysis ability.3.After induced mutations in the fungus aspergillus Niger and molds Kang Shimu UH X1U4-1-1 mixed fermentation,enzyme production when inoculation ratio of 9:1 ability stronger than aspergillus Niger fermentation separately,the higher the proportion of aspergillus Niger vaccination when circumscribed glucanase live,beta wood poly glycosides enzyme enzyme activity,the higher the beta glycosidase enzymes enzyme activity.When the activity of xylanase was consistent,aspergillus Niger and candida kongensis could produce high yield of reducing sugar by fermentation alone.This study shows that the combined mutation of uv-diethyl sulfate can effectively carry out mutagenesis breeding of mucor and aspergillus Niger and improve its enzyme production performance and straw hydrolysis ability.