Fig. 3

Reduction of glycerol production by expression of an alternative oxidase pathway. A Scheme of the alternative oxidase pathway comprising the mitochondrial external NADH oxidase Nde1 and the heterologous inner membrane enzyme Aox1, which shuttles reducing equivalents directly from ubiquinone (UQ) to oxygen. B Production of 2,3-BDO from glucose by the PDC-negative strain HGS7 overexpressing bdhA. The fermentation was performed in 50 ml medium in a shake flask. C Production of 2,3-BDO from glucose by strain HGS21 expressing Nde1 and Aox1. The fermentation was performed in 50 ml medium in a shake flask. D Production of 2,3-BDO from glucose by strain HGS31 in which GPD2 is replaced by NDE1. E Production of 2,3-BDO from glucose by strain HGS38 in which both GPD1 and GPD2 are replaced by NDE1