| 摘要 |
FIELD: biotechnology, microbiological industry, amino acids. ^ SUBSTANCE: method involves preparing L-leucine using microorganism belonging to genus Escherichia that produces L-valine, L-isoleucine and L-homoleucine in the amount less 1% of the amount of produced L-leucine. This effect is caused by inactivation of gene ilvE encoding the branch-chain-amino-acid aminotransferase. This microorganism produces the enhanced amount of L-leucine due to elevating activity or aromatic-amino-acid transaminase encoding by gene tyrB. Invention provides enhancing yield of L-leucine in reducing production of L-valine, L-isoleucine and L-homoleucine. ^ EFFECT: improved preparing method, valuable properties of strain. ^ 8 cl, 1 dwg, 1 tbl, 3 ex |
