The Condition Optimizing About Cellulose Enzyme Production Of Aspergillium Nige(AS3.316) And Using Heavy-ion Mutagenesis Technology To Select The High-yield Strains

Aspergillus niger is an important Industrial strains, which can produce amylase,acid protease, Cellulose enzyme, pectinase, glucose oxidase, citric acid, gluconic acidand gallic acid. In the production of cellulose enzyme, especially in the food industryand feed industry, Aspergillus niger has been to the focus of research.Using Aspergillus niger（AS3.316）, provided by China Center of IndustrialCulture Collection, which can produce cellulose enzyme, choosing the best mediumand culture conditions then using heavy-ion beam(¹²C⁺⁶) irradiation provided by statekey laboratory of Institute of Modern Physics, Chinese Academy of Sciences to makethe mutant strain breeding.（1） Adopting the cellulose enzyme vitality for the index, using single factorexperiment and orthogonal test to choose the best medium and culture conditions forAspergillus （AS3.316）. Finally, obtaineding the best medium for Aspergillusniger（AS3.316） to produce the cellulose enzyme is corn straw powder60g, bran40g,Tween-804ml,（NH₄）₂SO₄8g, KH₂PO₄0.5g, NaCl0.15g, FeSO₄0.05g, MgSO₄0.2g, MnSO40.16g, H₂O1000ml, making strains accessed into the best mediumaccording to the inoculation amount9%, putting in shaker ferment72h, which in thecondition of temperature28℃, initial pH4.5, revolution220r/min. Through thedetermination, filter paper enzyme vitality, end-glucanase enzymes vitality,exo-glucanase enzymes vitality and β-glucosidase enzymes vitality respectively for71.3U/ml,116.2U/ml,29.9U/ml,35.9U/ml, the production of enzymes is good.（2） Choosing20Gy,40Gy,60Gy,80Gy,100Gy,120Gy,140Gy doses ofheavy-ion beam to induced mutation for Aspergillus niger（AS3.316）, studing therelationship between irradiation dose and the death rate as well as the relationship between irradiation dose and mutation rate, getting the lethal dose is140Gy.Through the Initial screening and complex screening to choose12strains mutants,there are T1-1, T1-2, T2-1, T2-2, T3-1, T5-1, T5-2, T5-3, T6-1, T6-2, T6-3, T6-4,which have higher cellulose enzyme vitality. In120Gy radiation doses,getting4trains mutants, The cellulose enzyme activity of T6-4is the highest, filter paperenzyme vitality, end-glucanase enzymes vitality, exo-glucanase enzymes vitality andβ-glucosidase enzymes vitality respectively for71.3U/ml,116.2U/ml,29.9U/ml,35.9U/ml, compared with original Aspergillus niger （AS3.316）, the cellulose enzymevitality are increased by2.91,3.79,3.11,2.70times in turn.（3） The result of stability testing for12strains mutants,getting5strains mutantsshown the stability, there are T2-1, T3-1, T5-1, T6-3, T6-4, and5mutants celluloseenzyme are sorted from strong to the weak is T6-4> T6-3> T5-1> T3-1> T2-1,through stability testing of9generation,the rangeability of the cellulose enzymevitality is within5%.