跳到主要內容

臺灣博碩士論文加值系統

(44.210.149.205) 您好!臺灣時間:2024/04/16 18:58
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果 :::

詳目顯示

我願授權國圖
: 
twitterline
研究生:李如月
研究生(外文):Lee, Ruth
論文名稱:纖維二糖�忖圻X成及其固定化應用
論文名稱(外文):Production and immobilization of β-glucosidase (cellobiase)
指導教授:阮若屈;李文乾
指導教授(外文):Ruann,Ruoch Chyu;Lee,Ween Chein
學位類別:碩士
校院名稱:中原大學
系所名稱:化學工程研究所
學門:工程學門
學類:化學工程學類
論文種類:學術論文
論文出版年:1994
畢業學年度:82
語文別:中文
論文頁數:101
中文關鍵詞:水解β-葡萄糖菌絲連結的纖維二糖纖維雙糖固定化褐藻膠鈣
外文關鍵詞:Hydrolysisβ-GlucosidaseMycelial-associated cellobiase
相關次數:
  • 被引用被引用:1
  • 點閱點閱:301
  • 評分評分:
  • 下載下載:0
  • 收藏至我的研究室書目清單書目收藏:0
來自 Trichoderma reesei QM9414 之β-葡萄糖(即纖維二糖) ,目
前已證實它在 T. reesei 的纖維分解複合體內將纖維素完全水解成葡
萄糖中扮演重要的角色。因為此酵素主要是與 T. reesei的菌絲體連結在
一起, 僅少部份會分泌至培養液內, 因此若能生產含高活性酵素的菌絲
體, 並將其固定化, 將可提高此酵素在纖維素水解過程中的使用效率。本
研究首先以 T. reesei QM9414 進行液態培養, 探討其最佳合成條件, 以
期得到含高酵素活性之菌絲體。結果是以0.2%葡萄糖為碳源時, 在 30℃
、250rpm下培養 24h 後( 此時葡萄糖已即將耗盡 ),直接加入纖維雙糖當
做誘導劑, 加入纖維雙糖之含量為 0.05%, 再培養四天回收其菌絲體 ,
此時可得與菌絲連結的較高活性之纖維二糖,其活性為0.324U/mg dry
wt mycelium 。不加任何誘導劑, 僅以0.2%葡萄糖培養五天時, 其組成性
之酵素活性為 0.101U/mg dry wt mycelium。若以較高濃度即0.3%之葡萄
糖為碳源培養一天後, 以纖維雙糖誘導所得到的酵素明顯偏低, 顯示誘導
劑的添加時機以葡萄糖將耗盡時較佳。將含纖維二糖活性之菌絲體固定
於2%的褐藻膠鈣球顆粒, 可用來催化水解纖維雙糖為葡萄糖, 完成纖維素
水解的最後步驟。褐藻膠鈣球內所固定的菌絲體濃度對纖維雙糖的水解動
力學有相當程度的影響, 實驗結果配合水解的數學模式發現, 除了基質及
產物進出褐藻膠鈣球內的擴散效應外, 菌絲體濃度增加酵素的最大活性會
下降, 其原因可能為密集的菌絲會造成立體阻礙作用或是產物(葡萄糖)的
回饋抑制作用使得菌絲上可用酵素活性減低。本研究所提的數學模式, 配
合實驗數據可求得動力學參數的固定值, 這些參數值為設計反應器所必需

Beta-Glucosidase (cellobiase) of Trichoderma reesei QM9414 has
been shown to play a key role in the hydrolysis of cellulose
to glucose by the cellulase complex of T. reesei. Because
this enzyme is mainly associated with mycelium of T. reesei
and only partially released into the medium, it would be
produced in the mycelium-bound form and immobilized on solid
support for the ap- plication to cellulose hydrolysis. In this
work, the best condition for the synthesis of cello- biase
were investigated in order to obtain a higher activity of
mycelial-associated cellobiase from T. reesei by
submerged culture. The one-day old culture on glucose (0.2%)
medium was incubated with cellobiose (0.05%) as the inducer
for cellobiase production. The activity of mycelial-
associated cellobiase reached 0.324 U/mg dry wt. mycelium on
fourth day after addition of inducer. The good time for
inducer addition was when the glucose in the medium was
exhausted. However, the mycelia produced constitutive
cellobiase with an activity of 0.101 U/mg dry wt. mycelium in
5-day culture on glucose medium. The immobilization of the
mycelial-associated cellobiase was carried out by encapsulating
the harvested mycelia in 2% calcium alginate beads. This
immobilized cellobiase was then employed to hydrolyze
cellobiose. Experimental results revealed that the biomass
concentration in the matrix harboring myucelial- associate
cellobiase was the most important factor to influence the
kinetics of cellobiose hydrolysis. Besides the effect of
diffusion limitation for substrate and product, the
higher biomass concentration would lead to an effect of
steric hin- drances which reduced the maximum reaction rate
of cellobiose hydrolysis. The intrinsic kinetic parameters
were obtained by fitting the experimental data with
mathematicalmodel.
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top