The administration of L-cysteine and L-arginine inhibits biofilm formation in wild-type biofilm-forming yeast by modulating FLO11 gene expression.

Microbial biofilms are undesired in food manufacturing, drinking water distribution systems, and clinical realms. Yeast biofilms are particularly problematic because of the strong capacity of yeast cells to adhere to abiotic surfaces, cells, and tissues. Novel approaches have been developed over recent years to prevent the establishment of microbial biofilms, such as through the use of small molecules with inhibiting and dispersing properties. Here, we studied the inhibitory activity of 11 different amino acids on the biofilm formation ability of three wild-type Saccharomyces cerevisiae strains and the reference strain ∑1278b. Subsequent evaluation of different concentrations of the two most effective amino acids, namely, arginine and cysteine, revealed that they acted in different ways. Arginine prevented biofilm formation by reducing FLO11 gene expression; its addition did not affect cell viability and was even found to enhance cell metabolism (vitality marker) as determined by phenotype microarray (PM) analysis. On the contrary, the addition of cysteine reduced both cell viability and vitality as well as FLO11 expression. Thus, the use of cysteine and arginine as agents against biofilm formation can be diversified depending on the most desired action towards yeast growth.