In a previous paper, it was shown that the spoilage yeast
Zygosaccharomyces bailii was resistant to a variety of toxic weak acids, due to a long “tail” of increasingly resistant cells within the population
(Stratford et al., 2013).
The resistant sub-population exhibited crossresistance
to all other weak acids, showing that resistance was not
dependent on the acid structure and implying a mechanism thatlowered uptake of all acids.
The theory that the resistant subpopulation had a lower cytoplasmic pH, which reduced the quantity of weak acids accumulated, was proposed.