基因工程在L-色氨酸生产中的应用研究进展

Advances in synthesis of L-tryptophan by genetic engineering

尽管L-色氨酸的生产已取得诸多进展,但由于其合成代谢途径长、调控复杂,故一直未能达到工业化生产的要求。本文主要概述近年来通过构建色氨酸合成酶和色氨酸酶基因工程菌株与酶法相结合来生产L-色氨酸方面的进展及其局限性,并从增加前体物质代谢流、限速酶量和消除途径抑制因素等方面着重论述第三代基因工程———代谢工程在L-色氨酸生产方面的研究状况,指出代谢工程育种为今后色氨酸育种的主要方向。

Although great progress has been made in the research on L-tryptophan synthesis in recent years, it is still not satisfactory in meeting the economic demands for industrial production, because of the long metabolic pathway and complex regulation mechanism in L-tryptophan synthesis. The advances in the construction of an engineering bacterium related to tryptophan synthase and tryptophanase, as well as in the synthesis by enzyme methods are reviewed and their disadvantages are discussed. The metabolic engineering, known as the third generation of gene engineering brings new perspectives to this field. The possibility in enhancing L-tryptophan synthesis by increasing the copies of key enzymes and supply of precursors, and removing some limiting factors in the metabolic pathway is mainly discussed. Undoubtedly, modification of L-tryptophan breeding by metabolic engineering will become an important aspect in the research on L-tryotophan synthesis in the future.