Functional classification of the genes affected by the PACI transcription factor. A, genes that are either up-regulated or down-regulated in the pac1 deletion strain as compared to the parental strain QM9414. Blue bars indicate the number of genes up-regulated in the Δpac1 strain as compared to the parental strain, and red bars the number of genes down-regulated in the Δpac1 strain as compared to the parental strain; B, candidate genes under PACI regulation according to statistically significant difference in expression at different pH and in comparison of the parental strain and the ∆pac1 strain Classification is based on Eukaryotic orthologous groups. Glycoside hydrolase, carbohydrate esterase and polysaccharide lyase genes were annotated according to . The genes that are up-regulated at high pH are designated as “High pH up-regulated”, and the genes up-regulated at low pH are designated as “Low pH up-regulated”.