Preliminary study on metabolic regulation and control of L-valine fermentation in a newly screened L-valine producing Brevibacterium flavum strain

Abstract

A L-valine hyper-producer Brevibacterium flavum XQ-6 (Leul, Ilel, AHVr, -ABhr, 2-TAhr) was obtained, which could be resistant to high concentration of -amino-butyric acid (-AB) and 2-thiazolealanaine (2- TA). The metabolic network of XQ-6 was regulated with the addition of amino acids, organic acids,
vitamins, bases and other organic things. The carbon flux was directed to L-valine by manipulating the specific activity of -ketoglutarate dehydrogenase complex (KGDH). With a combinational regulation strategy, the highest L-valine concentration of 67.7 g/L was achieved.