ENGINEERING BACTERIA FOR PRODUCING DL-ALANINE AND METHOD FOR PRODUCING DL-ALANINE BY USING ENGINEERING BACTERIA

摘要

The present invention discloses a DL-alanine-producing engineering bacterium. This DL-alanine-producing engineering bacterium itself was inactivated in lactate dehydrogenase, pyruvate formate lyase, alcohol dehydrogenase, acetate kinase, fumarate reductase, alanine racemase, and methylglyoxal synthase; moreover, onto the chromosome thereof an exogenous L-alanine dehydrogenase gene and alanine racemase gene were integrated. In the present application, by integrating the exogenous L-alanine dehydrogenase gene into the chromosome of the engineering bacterium, the intermediate of glycolysis, pyruvic acid, was converted into L-alanine; by further integrating the exogenous alanine racemase gene, partial L-alanine was converted into D-alanine, achieving the direct production of DL-alanine from raw material saccharides, thereby decreasing the production cycle of DL-alanine, and increasing the yield of DL-alanine.

主权项

1. A DL-alanine-producing engineering bacterium, characterized in that: each of the lactate dehydrogenase gene, pyruvate formate lyase gene, alcohol dehydrogenase gene, acetate kinase gene, fumarate reductase gene, alanine racemase gene and methylglyoxal synthase gene on chromosome of an original bacterium is inactivated; and onto the chromosome thereof an exogenous L-alanine dehydrogenase gene and exogenous alanine racemase gene are integrated, and then, the DL-alanine-producing engineering bacterium is obtained by screening.