Method for preparing l-2-aminobutyric acid through whole cell biotransformation

Abstract

The invention relates to a method for preparing L-2-aminobutyric acid through biotransformation of whole cells. The method is as follows: expressing threonine deaminase and leucine dehydrogenase in series, cloning the chloramphenicol resistance expression vector, realizing the co-expression of the two enzymes in the same bacterium; cloning the formate enzyme into kalamycin Express on the resistant pET-28a vector, and express in tandem with the pcnB gene in the rate-limiting step of the coenzyme I metabolic pathway in E. coli to achieve high expression of the two enzymes; transform the two resistant expression vectors into the same bacterium Co-expression in the same genus of the four enzymes was achieved, and the expression of four enzymes in the same genus was realized; the whole cell of E. coli containing the four enzymes was fermented and expressed in E. coli, and the synthesis from threonine to L-2-aminobutyric acid was realized. Bioreductive transformation. The invention realizes high-efficiency conversion of 2-ketobutyric acid in the conversion system without adding coenzymes, and has low cost and simple method.

Description

technical field [0001] The invention relates to a method for preparing L-2-aminobutyric acid through biotransformation of whole cells. Background technique [0002] L-2-aminobutyric acid is an important pharmaceutical intermediate and chemical raw material, and the market demand is very large, with an annual market of more than 2,000 tons. At present, the industry mainly uses chemical methods for synthesis. The advantage of the chemical method is that the preparation cost is low, but it pollutes the environment seriously. With the improvement of the country's requirements for environmental protection, the preparation of L-2-aminobutyric acid by the biological method is favored by people. The advantage of the biological method is that the pollution is small and the environment Friendly, which belongs to green industrial products, is the direction of development. However, the current biotransformation method has many steps, involves enzyme preparation, and needs to add coenz...

AI Technical Summary

Problems solved by technology

However, the current biotransformation method has many steps, involves enzyme preparation, and needs to add coenzymes to the bioreduction transformation system, and the cost cannot be compared with chemical synthesis.