L-THREONINE OVERPRODUCING MICROORGANISM WHICH CONSTRUCTED BY SPECIFIC GENETIC MODIFICATIONS AND METHOD FOR PREPARING L-THREONINE USING THE SAME

摘要

A mutant microorganism is provided to produce L-threonine with high yield and provide accurate information regarding genetic characteristics of an L-threonine producing microorganism, thereby being used to develop an additional. A method for preparing an L-threonine producing mutant microorganism comprises a step of inducing mutation of a microorganism such as bacteria, yeast and fungus through: (a) deletion of a gene encoding a repressor of a lac operon, a gene encoding a homo-serine O-succinic transferase, a gene encoding diaminopiperate dicarboxylase and a gene encoding an L-threonine dehydrogenase; (b) mutation of genes encoding aspartokinase I and aspartokinase III for preventing the activities inhibition of the aspartokinase I and aspartokinase III; and (c) substitution of an L-threonine operon promoter or a promoter of acetyl coA synthetase with a strong promoter, wherein the bacteria is selected from the group consisting of Corynebacterium sp., Brevibacterium sp. and E. coli.