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Study On The Mutation Of White-Rot Fungi And Aspergillus Niger By Radiation Of ~(60)Co Gamma Rays And Biodegradation To Lignin

Posted on:2004-12-18Degree:MasterType:Thesis
Country:ChinaCandidate:B Y ZhangFull Text:PDF
GTID:2120360122998232Subject:Animal Nutrition and Feed Science
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White-rot fungi (5.132 coriolus versicolor fome) and Aspergillus Niger (3.316) are all filar fungus, white rot fungi (5.132) excretes laccase and Mn-peroxidase(Mnp); Aspergillus niger(3.316) excretes endoglucanase (EG), xylanase(EC) and B-glucosidase ( BG), Two species have high degradability to cellulose ,hemi-cellulose and lignin.The degradability of White-rot fungi (5.132) and Aspergillus Niger (3.316)were investigated to bagasse by solid-state fermentation for thirty days, the result shown :(1) The degradability of white-rot fungi to neutral detergent fibre (NDF) is 16.87% and to Klason lignin is 26.63%.(2) After Aspergillus Niger (3.316) degraded, neutral detergent fibre (NDF) and Klason lignin is higher than before.In this study , Sporule suspension of white-rot fungi (5.132) and Aspergillus Niger (3.316) are radiated with 60Co gamma rays under the different radiate dose and different radiate time. Enzyme vitalities of laccase and Mn-peroxidase, endoglucanase (EG) and B-glucosidase (BG)were mensurated. compared with original strains ,their Enzyme vitalities are higher than original strains. 60Co gamma rays have physiological and biochemical effect on fungus sporules which is radiated. Enzyme vitality enhancing attributed two effects or single effect, biochemical effect include gene mutation .Byseveral multiply and repeated isolated, getting six high produced strains of white rot fungi, study shown, six isolated strains of white rot fungi have higher enzyme vitality and mycelial weightiness, and that enzyme vitality have good stabilization, mutation strains have no difference in the demand of carbon source and nitrogen source from original strains. The research of solid-state fermentation of bagasse indicated, six high produced strains of white-rot fungi have higher degradability to cellulose and lignin than original strains ,the difference is evident. The result shown :(1) The effect of 60Co gamma rays on white-rot fungi and Aspergillus Niger is evident. Under the 0.6kgy dose, white-rot fungi deadly rate is 94.6%, Aspergillus Niger deadly rate is 99.49%; under 1.2kgy dose, livability rate of white-rot fungi is 0.0045%, livability rate of Aspergillus Niger is 0.0026%.Result of isolation for positive mutation of Aspergillus Niger is zero.(2) white-rot fungi laccase vitality enhance 157.7%, Mnp vitality enhance 137.24%. mutiply four times, laccase and Mn-peroxidase vitality have good stabilization.(3) After solid state fermentation, original strains degradability to bagasse NDF is 16.87%, to Klason lignin is 26.63%, mutation strains degradability of NDF to bagasse is 28.01%, to Klason lignin is 40.75%.
Keywords/Search Tags:White-rot fungi, Aspergillus Niger, 60Co gamma rays, Bagasse Solid-state, Fermentation
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