Dissertation > Excellent graduate degree dissertation topics show

The Reform and Study Ofsite-directed Mutagenesis of Acid Xylanase XynⅢ from Aspergillus Niger

Author: HuangZhongZuo
Tutor: LiuLiangWei
School: Henan Agricultural University
Course: Microbiology
Keywords: Xylanase pH stability over-1ap PCR site-directed mutagenesis
CLC: TQ925
Type: Master's thesis
Year: 2011
Downloads: 3
Quote: 0
Read: Download Dissertation

Abstract


Although xylanases have widely been used in the paper industry, the feed industry the brewing, the energy industry as well as in the foodstuff industry. For example they can be u`sed in biological bleaching of paper pulping, improving the environment and the nutritive value of the forage . The application of xylanases in industry have the different requirements in pH. In most condition,we require them reaction in the low pH condition. for example,in the feed industry, as the feed additive xylanases should effect in the low pH condition.But,the most acid resistance of the much xylanases are very poor.,it is essential to improve the properties of xylanases acid resistance for broader applications.In this experiment, we dislodge the extra alignment by PCR, and link the pET-20b. The results show that the extra alignment impact the character of xylanases.In our study, we change the amino acid which after the amino acid Y to amino acid S, because the Amino acid diad YS was Negative correlation to the XynⅢenzyme about pH in former study.We got 9 Mutated xylanase gene, by PCR and overlap PCR, and link them to pMD19-T Vector respectively, then digest with NdeⅠand XhoⅠ, and connected with the digested pet-20b. and now we have connected No.1, No.2 and No.4 to expression vector pet-20b, then transformed the recombinant plasmids with the mutant gene to BL-21 and got expressed, then we got the proteins with the activity of xylanase.After the research of the character of the recombinases, we find that The optimum pH of the reformed xylanase was about 4.0, both the No.1 No.4 of the mutant xylanase were lower than the reformed xylanase, and the change of No.2 was not obvious.

Related Dissertations

  1. Cloning and Expression of Xylanase Gene from Thermobifida Halotolerans YIM 90462~T,Q78
  2. Study of a Thermophilic Bacteria Chitin-binding Domain and Its Application in Immobilized Enzyme,Q814
  3. Isolation of Xylanase Producing Bacteria from the Large Intestine of Adult Inner Mongolia Black Sow and Its Enzyme Producing Factors,S816.7
  4. The Effect of High-level Copper and Zinc Addition on the Performance, Digestibilities and Gastrointestinal Enzyme Activities of Weaned Piglets,S828.5
  5. Characterization and Reaction Kinetic of Biphenyl Hydrolase from Rhodococcus sp. R04,Q55
  6. Bovine prochymosin gene mutagenesis and enzymatic properties of,Q814
  7. Stability of Recombinant Enzyme Preparation of α-CGTase,Q814
  8. Improving Thermostability of the Penicillium Expansum Lipase by Molecular Mutagensis,Q55
  9. High-effective Catalytic Characteristics of Glycerol Dehydratase from K.pneumoniae XJPD-Li,Q814
  10. Effects of Enzyme Preparation on Growth Performance and Nutrient Digestibility in Ducks,S834.5
  11. Construction of Gene Engineered Bacteria of Xylanase and Its Recombined Enzymatic Properties,Q78
  12. Construction of Pichia Pastoris Engineering Strain for Degumming Pineapple Leaf Fiber and Its Expression、Application,Q78
  13. The study of the original strain of the xylanase enzyme nature visits,Q814
  14. The xylanase Y3 screening and nature of the visits,X172
  15. Improvement of Thermostability of Bacillus Amyloliquefaciens BS5582 β-1,3-1,4-glucanase Through Vitro Evolution,TQ925
  16. Gene Cloning and Expression of a Novel (S)- Carbonyl Reductase from Candida Parapsilosis,TQ925
  17. Cloning and Expression of Bacillus Subtilis β-mannanase Gene,TQ925
  18. Screen of Strain Producing Xyalnase , Optimization of Production Conditions and Effect of Xylanase on Perormance of Broilers,S831.5
  19. Engineering of Volvariella Volvacea Glycoside Hydrolase Family 5 Endoglucansel for Improved Thermostability,Q946
  20. Through site-directed mutagenesis of methyl parathion hydrolase improve the thermal stability of MPH,X592

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