Knockout Mutations in the Genes Encoding Phosphate Transporters Impair Adaptation of Saccharomyces cerevisiae to Ethanol Consumption

Phosphate transporters in yeast cells are responsible for phosphorus homeostasis and are also indirectly involved in the regulation of various adaptive processes. One of these processes is the adaptation to ethanol consumption, which requires significant changes in phosphorus metabolism. We have demonstrated that knockout mutations in the genes PHO87, PHO89, PHO90, and PHO91, encoding phosphate transporters, impair the adaptation of Saccharomyces cerevisiae to ethanol consumption at an ethanol concentration of 4%. For these mutant strains, an extension of the lag phase and a decrease in the growth rate at the active stage were observed. Mutant cells differed from the parental strain in the content of inorganic polyphosphates, but not orthophosphate: they contained less long-chain polyphosphates when cultivated on ethanol, but not on glucose. When cultivated in a medium containing 4% ethanol, the strain with a knockout mutation in the PHO84 gene encoding the transporter of phosphate and divalent metals, as well as knockout strains for the PHM6 and PHM7 genes responsible for the polyphosphate overplus, did not show any growth differences compared to the parent strain in the medium with 4% ethanol. The possible role of phosphate transporters and inorganic polyphosphates in the adaptation of yeast to ethanol consumption is discussed.