加电固定化膜式反应器生产L-丙氨酸

L-Alanine production by electric membrane bioreactor of immobilized cells

选用突变株P .dacunhaeDQ p1菌 ,利用加电固定化细胞膜式反应器生产L 丙氨酸 ,旨在消除产物L 丙氨酸对L 天冬氨酸 β 脱羧酶的竞争性抑制。研究结果表明 :加静电优于通电流 ;随着静电压的加大 ,表观米氏常数Km′变小 ,说明该反应器的使用一定程度地解除了产物的抑制 ;结果还表明对于表观抑制常数Ki′存在阈值 ,本实验范围内阈值约为 9～ 1 2V ,外加静电压超过阈值时 ,Ki′显著增大。底物转化率与停留时间反应器动力学方程的数学模型为τ =ax +bln[1 /( 1 -x) ]。

This paper reports the production of L alanine with the electric membrane bioreator of immobilized P. dacunhae DQ p1 cells. It is aimed at overcoming the competitive inhibition of the product L alanine on L aspartate β decarboxylase. Experimental results show that static electricity is superior to current. The higher the static voltage is, the less the K m′ will be. It shows that the electric membrane bioreator of immobilized cells can partly overcome the inhibition of the L alanine product. It also shows that there is a K i′ threshold whose value is 9 12V. Once the static voltage exceeds the threshold, the K i′ become bigger dramatically. Finally the model of reaction kinetics is established as: τ=a x+b ln[1/(1- x )].