A recombinant yeast cell functionally expressing: a) a nucleic acid sequence encoding a protein comprising phospho-ketolase (PKL) activity (EC 4.1.2.9 or EC 4.1.2.22) and/or a nucleic acid sequence encoding a protein having phosphotransacetylase (PTA) activity (EC 2.3.1.8) and/or a nucleic acid sequence encoding a protein having acetate kinase (ACK) activity (EC 2.7.2.12); and/or) a nucleic acid sequence encoding a protein having transketolase activity (EC 2.2.1.1), wherein the expression of the nucleic acid sequence encoding the protein having transketolase activity is under control of a promoter (the TKL promoter), which TKL promoter has an anaerobic/aerobic expression ratio for the transketolase of (2) or more.