Enhancement of Acetic Acid Tolerance in Saccharomyces cerevisiae by Overexpression of the HAA1 Gene, Encoding a Transcriptional Activator

Haa1 is a transcriptional activator required for Saccharomyces cerevisiae adaptation to weak acids. Here we show that the constitutive HAA1-overexpressing strain acquired a higher level of acetic acid tolerance. Under conditions of acetic acid stress, the intracellular level of acetic acid was significantly lower in HAA1-overexpressing cells than in the wild-type cells.