C12Y106/06

RECOMBINANT YEAST CELL

A recombinant yeast cell functionally expressing: a) a nucleic acid sequence encoding an enzyme having NADH-dependent nitrate reductase activity and/or a nucleic acid sequence encoding an enzyme having NADH-dependent nitrite reductase activity; and b) 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.