Genetic manipulation of 6-phosphofructo-1-kinase and fructose 2,6-bisphosphate levels affects the extent to which benzoic acid inhibits the growth ofSaccharomyces cerevisiae

The mechanisms by which the weak acid preservative benzoic acid inhibits th e growth of Saccharomyces cerevisiae have been investigated, A reduction in the pyruvate kinase level, which decreases glycolytic flux, did not increa se the sensitivity of yeast to benzoic acid, However, a decrease in 6-phosp hofructo-1-kinase (PF1K), which does not affect glycolytic flux, did increa se sensitivity to benzoic acid. Also, resistance was increased by elevating PF1K levels. Hence, resistance to benzoic acid was not dependent upon opti mum glycolytic flux, but upon an adequate PF1K activity. Benzoic acid was s hown to depress fructose 2,6-bisphosphate levels in YKC14 a mutant with low PF1K levels, This effect was partially suppressed by overexpressing consti tutively active 6-phosphofructo-2-kinase (pfk26(Asp644)) or by inactivating fructose-2.6-bisphosphatase (in a Delta fbp26 mutant). The inactivation of PF2K (in a Delta pfk26 Delta pfk27 mutant) increased benzoic acid sensitiv ity, Therefore, the antimicrobial effects of benzoic acid can be relieved, at least in part, by the genetic manipulation of PF1K or fructose 2,6-bisph osphate levels.