Dissertation > Excellent graduate degree dissertation topics show

Mutation and Application of Raw Starch-Digesting Glucoamylase Strain

Author: ZuoYuXiu
Tutor: PangZongWen
School: Guangxi University
Course: Fermentation Engineering
Keywords: raw starch-digesting glucoamylase response surface analysis mutation enzymology properties
CLC: TQ925
Type: Master's thesis
Year: 2011
Downloads: 59
Quote: 0
Read: Download Dissertation

Abstract


Rhizopus sp.2 stored in our laborator is a strain that can produce raw starch-digesting glucoamylase at high level. In this experiment, raw starch-digesting glucoamylase produced by Rhizopus sp.2 was applied in ethanol fermentation, and the conditions of ethanol fermentation under 37℃using raw cassava srarch with was studied. By single factor experiment and response surface analysis optimization, the optimum fermentation conditions were:pH 4.6, fermentation time 68.9 h, enzyme 173.00 U/g, material/liquid 1:3.5, yeast inoculum size 108/mL, urea 0.2%(w/v). Fermenting under these conditions, the predictive value of alcohol concentration was 9.90%(v/v), and the actual alcohol concentration was 9.95%(v/v). Besides, shaker fermentation、adding glucoamylase and adding a-amylase had no significant improvement on the alcohol fermentation. High-gravity fermentation of cassava ethanol fermentation was preliminary studied，the material water ratio was 1:3.5，when fermentation time was 60 h, the maximum alcohol concentration reached 12.89%(v/v)Using Rhizopus sp.2 as the starting strain, mutant strain UL16 was obtained, and its raw starch-digesting glucoamylase activity increased by 28.29% average than that of the starting strain. At the same time, resistant mutant strain was screened by adding 2-D-deoxyglucose, mutant strain K7 was obtained, its enzyme activity rised in an average of 25.44%. The enzyme production of UL16 and K7 were very steady through passage experiments.Raw starch-digesting glucoamylase was initially purified by ammonium sulfate, and enzymology properties of raw starch-digesting glucoamylase was partly studied. The optimum temperature was 40℃. The optimum pH was in the range of 4.0～4.8. Enzyme was more stable under 50℃, and its activity declined sharply when over this temperature. The enzyme performed stably in range of pH 4.8 to 9.0 and the residual enzyme activity maintained more than 80%. Hg2+、Ni2+、Ag+ and Fe3+ showed inhibition to the enzyme activity, K+、Fe2+ and Na+ had no effect on the enzyme, Li+、Co2+、Zn2+、Cu2+、Mg2+、Pb2+、Ca2+ and Mn2+ could activate the enzyme activity, Mn2+ had great activation on the enzyme activity especially, which increased by 88.42%.

Related Dissertations

  1. Purification of Endogenous Proteases from (Litopenaeus Vannamei) Shrimp Head and Their Enzymology Properties,S985.21
  2. Breeding of Fungal α-amylase High-producing Strain by Genome Shuffling,TQ925
  3. Screening, Bio-Characteristics and Biopulping Application of a High Pectin-Degrading Baeterial Strain by Ultraviolet-Ray Mutation,TS713
  4. Research on the Mutation Breeding of Flavomycin and Regulation of Fermentation Techniques,TQ920.6
  5. Effect of Single and Double Mutations of Yeast H3K79L、H4K20L on the Function of ELP3 and Expression of SSA3,Q75
  6. The Ethnology Research of Awe-inspiring Gong and Drum,J632.5
  7. The Structural Domain Analysis of p53 N-terminal Transcriptional Activation Domain Interaction with Actin,R730.2
  8. Development on the Sleep Improvement Functional Beverage Rice Wine,TS262.8
  9. Study on Enzymatic Hydrolysis Technology of Tuna By-products,TS254.9
  10. Whole Exome Capture Sequencing Identifies Candidate Genes Related to HCC,R735.7
  11. Modelling and Engineering Optimization of Ethylene Oxychlorination in Fluidized Bed Reactors,TQ221.21
  12. Screening Mutational Sites That Enhance Protein Thermostability by High Temperature Molecular Dynamics Method,Q51-33
  13. Two Novel Mutations of DSRAD Gene in Chinese Families with Dyschromatosis Symmetrica Hereditaria,R758.5
  14. Study on the Regulatory Mechanism of the Gene slr0280 from Synechocystis Sp. PCC6803,Q943
  15. Study on the Correlation between Genetic and Epigenetic Alterations of PTEN Gene in Soft Tissue Sarcomas,R738.6
  16. The Analysis of BRCA1 Exon 11、24 Mutations in the Patients with Early Onset Breast Cancer and Affected Relatives Live in Shandong, China,R737.9
  17. Gene Analysis of Glucose-6-phosphate Dehydrogenase(G6PD) in Neonates of Guangdong,R722.1
  18. Gene Mapping and Mutation Detection of A CIN with Hearing Impairment Family,Q987
  19. The Yangla copper pyrite comprehensive utilization of resources Xuanye test,TD913
  20. Study of Mutation and Breeding of Griseofulvin Produccing Strain FS80,TQ927
  21. Analysis of BRCA1 Gene Mutation in Ningxia Hui and Han People,R737.9

CLC: > Industrial Technology > Chemical Industry > Other chemical industries > Fermentation industry > Enzyme preparation ( enzyme )
© 2012 www.DissertationTopic.Net  Mobile