Saccharomyces cerevisiae displays an increased growth rate and an extended replicative lifespan when grown under respiratory conditions in the presence of bacteria.

Individual cells of the budding yeast Saccharomyces cerevisiae have a limited replicative potential, referred to as the replicative lifespan. We have found that both the growth rate and average replicative lifespan of S. cerevisiae cells are greatly increased in the presence of a variety of bacteria. The growth and lifespan effects are not observable when yeast are allowed to ferment glucose but are only notable on solid media when yeast are forced to respire due to the lack of a fermentable carbon source. Growth near strains of Escherichia coli containing deletions of genes needed for the production of compounds used for quorum sensing or for the production of the siderophore enterobactin also still induced the lifespan extension in yeast. Furthermore, the bacterially induced increases in growth rate and lifespan occur even across gaps in the growth medium, indicating that the bacteria are influencing the yeast through the action of a volatile compound.