Expression profiles of the gene pac1 and the homologues of palC and palF genes in the microarray data. A) Expression of the genes in cultures of the strain QM9414 at pH 3, 4.5 and 6. B) Expression of the genes in cultures of the Δpac1 strain and in QM9414 at pH 6. Expression level of the genes is the normalised signal in the microarray data (not log2 transformed values), data on the three biological replicates is averaged. The time point and pH of the culture, as well as the strain, is indicated in the X axis labels. QM is an abbreviation for QM9414.