微生物发酵法生产丁酸

论文编号:SW179  论文字数:15366,页数:32  附任务书，开题报告，文献综述

摘 要：丁酸（butyric acid）作为一种广泛应用于食品、化学和医药等行业的有机酸，其生产工艺以化学合成法为主，但随着人们环保意识的增强和石油能源的减少，生物合成法越来越受到社会的关注，本课题重点研究利用木薯淀粉、甘蔗废糖蜜和木糖渣等可再生资源微生物发酵法生产丁酸。
 丁酸发酵是一种终产物抑制发酵，因此微生物发酵法生产丁酸收率低而经济效益差，目前尚难替代化学合成法。本文探讨了丁酸的代谢合成途径；介绍了利用代谢工程手段选育丁酸梭菌突变株的最新进展以及固定化纤维床反应器和萃取发酵技术在丁酸发酵中的应用；分析了发酵法生产丁酸的存在问题，并对微生物发酵法生产丁酸的研究方向进行展望。
 本课题以酪丁酸梭菌Clostridium tyrobutyricum ATCC 25755为生产菌，葡萄糖为参照物，重点研究了木薯淀粉、甘蔗废糖蜜和木糖渣的预处理方法对菌体生长和发酵的影响。
 
键词：丁酸；酪丁酸梭菌 ；微生物发酵法

Abstract: Butyric acid is an organic acid widely used in food, chemical and pharmaceutical industries. Its production process bases chemical synthesis, but with the public awareness of environmental protection and the oil reduction, biological synthesis receives more and more concern of the community. This paper focuses on renewable resources like cassava starch, sugar cane molasses and xylose waste residue for the microbial fermentation to produce butyric acid.
     Because of butyric acid fermentation inhibited by its end products, microbial fermentation is both low productive and expensive nowadays and difficult to compete with chemical synthesis. The metabolic pathway of butyric acid is discussed here. Present advance in selective breeding of butyric-acid-producing bacteria by the means of metabolic engineering and applications of immobilized fibrous-bed bioreactor and extractive fermentation are introduced. After the problems in butyric acid production by microbial fermentation are analyzed, some ideas about its further development are presented.
   The paper used Clostridium Clostridium tyrobutyricum ATCC 25755 for the production of butyric acid and made glucose reference. It focused on the influence of the pretreatment of cassava starch, sugar cane molasses and xylose waste residue on the cell growth and the fermentation.

Keywords：butyric acid ;Clostridium tyrobutyricum ;microbial fermentation

目  录
中文摘要 I
英文摘要 II
目录 III
1. 绪论..1
 1.1 引言1
 1.2 丁酸的理化性质..1
 1.3 丁酸的生产菌株..2
 1.4 丁酸的作用和应用3
 1.5 丁酸的发酵工艺..4
 1.6 丁酸的生产方法..4
      1.6.1 化学合成制丁酸..4
      1.6.2 生物发酵法制丁酸5
 1.7 代谢合成途径及其调控..6
 1.8 本课题研究的意义和内容7
      1.8.1 研究意义..7
     1.8.2 研究内容..7
2. 材料与方法..8
 2.1 材料8
 2.1.1 菌种的来源8
 2.1.2 培养基及培养条件8
 2.1.3 主要仪器..8
 2.2 方法9
    2.2.1 原料预处理方法..9
     2.2.2 分析方法.10
  2.2.3 在搅拌反应器中的分批发酵..11
  2.2.4 FBB发酵.12
3. 结果与讨论.14
 3.1 原料预处理..14
 3.1.1 木薯淀粉酸水解.14
 3.1.2 甘蔗废糖蜜的稀释处理.14
 3.1.3 木糖渣的酸水解和酶水解..15
 3.2 生长曲线.17
 3.2.1 木薯淀粉水解液和葡萄糖为碳源..17
     3.2.2 不同稀释度的糖蜜为碳源..17
     3.2.3 木糖渣水解液为碳源18
 3.3 分批发酵.19
     3.3.1 以木薯淀粉水解液和葡萄糖为碳源19
     3.3.2 以甘蔗废糖蜜为碳源19
     3.3.3 以木糖渣水解液为碳源.20
 3.4 FBB发酵..21
     3.4.1 以木薯淀粉水解液和葡萄糖为碳源21
     3.4.2 以甘蔗废糖蜜为碳源22
4．总结与展望.23
 4.1 总结..23
 4.2 展望..24
致谢.25
参考文献26

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