微生物發(fā)酵法生產(chǎn)丁酸

生物工程論文編號:SW179  論文字數(shù):15366,頁數(shù):32  附任務(wù)書，開題報告，文獻綜述

目  錄
中文摘要 I
英文摘要 II
目錄 III
1. 緒論..1
 1.1 引言1
 1.2 丁酸的理化性質(zhì)..1
 1.3 丁酸的生產(chǎn)菌株..2
 1.4 丁酸的作用和應(yīng)用3
 1.5 丁酸的發(fā)酵工藝..4
 1.6 丁酸的生產(chǎn)方法..4
      1.6.1 化學合成制丁酸..4
      1.6.2 生物發(fā)酵法制丁酸5
 1.7 代謝合成途徑及其調(diào)控..6
 1.8 本課題研究的意義和內(nèi)容7
      1.8.1 研究意義..7
     1.8.2 研究內(nèi)容..7
2. 材料與方法..8
 2.1 材料8
 2.1.1 菌種的來源8
 2.1.2 培養(yǎng)基及培養(yǎng)條件8
 2.1.3 主要儀器..8
 2.2 方法9
    2.2.1 原料預(yù)處理方法..9
     2.2.2 分析方法.10
  2.2.3 在攪拌反應(yīng)器中的分批發(fā)酵..11
  2.2.4 FBB發(fā)酵.12
3. 結(jié)果與討論.14
 3.1 原料預(yù)處理..14
 3.1.1 木薯淀粉酸水解.14
 3.1.2 甘蔗廢糖蜜的稀釋處理.14
 3.1.3 木糖渣的酸水解和酶水解..15
 3.2 生長曲線.17
 3.2.1 木薯淀粉水解液和葡萄糖為碳源..17
     3.2.2 不同稀釋度的糖蜜為碳源..17
     3.2.3 木糖渣水解液為碳源18
 3.3 分批發(fā)酵.19
     3.3.1 以木薯淀粉水解液和葡萄糖為碳源19
     3.3.2 以甘蔗廢糖蜜為碳源19
     3.3.3 以木糖渣水解液為碳源.20
 3.4 FBB發(fā)酵..21
     3.4.1 以木薯淀粉水解液和葡萄糖為碳源21
     3.4.2 以甘蔗廢糖蜜為碳源22
4．總結(jié)與展望.23
 4.1 總結(jié)..23
 4.2 展望..24
致謝.25
參考文獻26

摘 要：丁酸（butyric acid）作為一種廣泛應(yīng)用于食品、化學和醫(yī)藥等行業(yè)的有機酸，其生產(chǎn)工藝以化學合成法為主，但隨著人們環(huán)保意識的增強和石油能源的減少，生物合成法越來越受到社會的關(guān)注，本課題重點研究利用木薯淀粉、甘蔗廢糖蜜和木糖渣等可再生資源微生物發(fā)酵法生產(chǎn)丁酸。
 丁酸發(fā)酵是一種終產(chǎn)物抑制發(fā)酵，因此微生物發(fā)酵法生產(chǎn)丁酸收率低而經(jīng)濟效益差，目前尚難替代化學合成法。本文探討了丁酸的代謝合成途徑；介紹了利用代謝工程手段選育丁酸梭菌突變株的最新進展以及固定化纖維床反應(yīng)器和萃取發(fā)酵技術(shù)在丁酸發(fā)酵中的應(yīng)用；分析了發(fā)酵法生產(chǎn)丁酸的存在問題，并對微生物發(fā)酵法生產(chǎn)丁酸的研究方向進行展望。
 本課題以酪丁酸梭菌Clostridium tyrobutyricum ATCC 25755為生產(chǎn)菌，葡萄糖為參照物，重點研究了木薯淀粉、甘蔗廢糖蜜和木糖渣的預(yù)處理方法對菌體生長和發(fā)酵的影響。
 
鍵詞：丁酸；酪丁酸梭菌 ；微生物發(fā)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