以吲哚和DL-丝氨酸为底物固定化酶法合成L-色氨酸

The Biosynthesis of L-tryptophan from Indole and DL-serine by Immobilized Enzyme

以化学合成的吲哚和DL-丝氨酸为底物,通过大肠杆菌Escherichia coli色氨酸酶促转化,生成L-色氨酸的同时也可获得D-丝氨酸,将DL-丝氨酸的拆分和L-色氨酸的合成同步化。下游工艺上,使用包埋法进行固定化酶促反应,进行了包埋条件的优化和固定化反应体系及反应条件的确立。最终,100mL反应体系中,包菌量16g,37℃反应24h,L-色氨酸可累积10.5g,相应吲哚转化率达75.5%。

The tryptophanase released from Escherichia coli was utilized to produce L-tryptophan from substrates of indole and DL-serine. Depending on the catalytic activities of tryptophanase,the biosynthesis of L-tryptophan was carried out through immobilized enzyme. As the result,10.5g L-tryptophan was formed in 100ml reaction mixture shaking for 24h at 37℃ when operating in the optimizing conditions of the down-stream technology,the conversion rate of indole reached 75.5 %.