Fig. 3

Enhancing α-ketoisovalerate production through increasing α-acetolactate synthase expression. (a) Biomass, substrate consumption, and α-ketoisovalerate generation of K. oxytoca KIV-2. (b) By-products generation by K. oxytoca KIV-2. (c) Metabolic flux of K. oxytoca KIV-2. Solid circles represent accumulated products; hollow circles indicate non-accumulated products; the area of the circles represents the carbon ratio of different products to glucose. The carbon ratio (%) was defined as the ratio of the theoretical amount of glucose required for production of different products to the total consumed glucose