Data underlying the study on Functional analysis of Saccharomyces cerevisiae FLO genes through optogenetic control

Flocculation in <em>Saccharomyces cerevisiae</em>, the calcium-dependent aggregation of yeast cells, is a critical phenotype with ecological and industrial significance. This study aimed to functionally dissect the contributions of individual <em>FLO</em> genes (<em>FLO1</em>, <em>FLO5,</em> <em>FLO9</em>, F<em>LO10</em>) to flocculation by employing an optogenetic circuit (OptoQ-AMP5) for precise, light-inducible control of gene expression. A <em>FLO</em>-null yeast strain (IMK1060) was engineered via CRISPR-Cas9 and homologous recombination, allowing the expression of individual <em>FLO</em> genes without native background interference. Each <em>FLO</em> gene was reintroduced into the <em>FLO</em>-null background under the control of OptoQ-AMP5. Upon light induction, strains expressing <em>FLO1</em>, <em>FLO5</em>, or <em>FLO10</em> demonstrated strong flocculation, with <em>FLO1</em> and <em>FLO5</em> forming large and structurally distinct aggregates. <em>FLO9</em> induced a weaker phenotype. Sugar inhibition assays revealed distinct sensitivities among flocculins, notably <em>FLO9</em>’s novel sensitivity to fructose and maltotriose. Additionally, <em>FLO</em>-induced changes in cell surface hydrophobicity were quantified, revealing that <em>FLO10</em> and <em>FLO1</em> conferred the greatest hydrophobicity, correlating with their aggregation strength. This work establishes a robust platform for investigating flocculation mechanisms in yeast with temporal precision. It highlights the phenotypic diversity encoded within the <em>FLO </em>gene family and their differential responses to environmental cues. The optogenetic system provides a valuable tool for both fundamental studies and the rational engineering of yeast strains for industrial fermentation processes requiring controlled flocculation.