通電透析発酵法のＬ‐リジン発酵への応用

Abstract

Aspartate kinase of Brevibacterium flavum QL-5 is inhibited by L-lysine plus L-threonine. Ele-ctrodialysis fermentation was applied to L-lysine production to reduce this inhibition. After 72 hr, the amount of L-lysine produced by electrodialysis fermentation was 57.2 g, which was 1.2 times greater than that by non-electrodialysis fermenta-tion (46.9 g), and similar to that by diffusion dialysis fermentation (57.0g). In electrodialysis fermentation, the L-lysine concentration in dialyz-ing solution was only 0.2%, while that in the fermentation broth was about 2%. It was sug-gested that production of L-lysine was limited by transport of L-lysine across the hollow fiber wall. L-Lysine monohydrochloride was added to the cul-ture broth at various culture stage, but the produc-tion of L-lysine was not influenced by the L-lysine added. Therefore, it was considered that the inhibition by L-lysine plus L-threonine in L-lysine production by Brevibacterium flavum QL-5 was not alleviated even when the L-lysine concentration in the fermentation broth was maintained at low by electrodialysis fermentation or diffusion dialysis fermentation.