利用寬口產鹼桿菌生產聚羥基烷酸酯之饋料批次發酵策略之研究

Studies on the production of polyhydroxyalkanoate by Alcaligenes latus using strategies of fed-batch fermentation

蘇裕隆(Yu-Long Su)

指導教授 ： 陳文章

國立臺北科技大學/工程學院/化學工程所/碩士(2005年)

摘要

為了將降低生產聚羥基烷酸酯(PHA)的生產成本，本研究採用便宜的營養基質來進行發酵培養，以搖瓶培養與發酵槽培養找出適合的發酵生產條件。
本研究利用蔬菜與水果當做原料經高溫高壓處理之後所得之果菜液來當培養基質，所使用菌株為寬口產鹼桿菌(Alcaligenes latus) 。以搖瓶實驗進行菌株馴化與找尋適合菌株生長的條件，實驗發現適合菌株生長的pH範圍約在6.0~8.0，在中心混成實驗發現在2g/L的硫酸銨，3.5g/L的磷酸二氫鉀與磷酸氫二鈉有最高PHA產量，而減少果菜液水份對菌株生長與PHA生產是有提升的效果。批次發酵槽實驗僅改變攪拌轉速下，對於A. latus菌株在果菜液中生長速率之提升有一定的範圍侷限，在轉速600rpm下菌株生長情形最好。進行饋料批次發酵實驗時，依不同比例的蔗糖與果菜液探討饋料培養條件與因子是否會對PHA產量影響效應大小，採用pH-stat的饋料方式，隨著蔗糖與果菜液之饋料濃度增加，PHA的產量也有提升，以5%、10%、20%蔗糖濃度之果菜液饋料，PHA產量分別為2.9、5.9、7.1g/L。以間歇式饋料策略發現高低不同濃度蔗糖之果菜液的饋料培養基會對菌株造成階梯式的生長情形，而對PHA的囤積情形則是持續快速上升再趨緩。以珠磨法破碎細胞所得產物之回收率約44%，以化學法所得產物之回收率約7%。

關鍵字

聚羥基烷酸酯 ； 寬口產鹼桿菌 ； 饋料批次發酵

並列摘要

Using inexpensive carbon sources for polyhydroxyalkanoate (PHA) fermentation could reduce the costs of production. So we used cheaper substrates for microbial cultivation. We used both the shaking cultivation and the fermentor cultivation to find suitable fermentation conditions.
In this study, Alcaligenes latus (BCRC 15440) was cultivated and the usage of vegie hydrolysate as the carbon sources was investigated for the production of PHA. We obtained higher productivity of organism via acclimation of A. latus in shaking culture. Best microbial growths occured over the pH range 6.0~8.0. In optimization and verification experiment via central composite method, the higest PHA yield occurred at 2 g/L of ammounium sulfate and 3.5 g/L of phosphate concentration. The rates of cell growth and production of PHA by transforming the vegie hydrolyate is good. When we changed the agitation speed in batch fermentation, the microbial growth rates could increase in very lmited range. The microbial growth in 600rpm was good. We also studied the effect of feeding solution at different ratio of sucrose and vegie hydrolysate on the production of PHA. When increasing sucrose concentration of fed-batch medium, the PHA yield could increase.The PHA yield was 2.9, 5.9, 7.1 g/L in 5%, 10%, 20% sucrose concentration of fed-batch medium. Higher concentration of fed-batch medium could increase cell growth but also improve PHA yield. The recover rate of purified PHA produced was 44% with bead mill method. The recover rate of purified PHA produced was 7% with chemical method.

並列關鍵字

polyhydroxyalkanoate ； Alcaligenes latus ； fed-batch fermentation

參考文獻

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