Saccharomyces cerevisiae— a model to uncover molecular mechanisms for yeast biofilm biology

Abstract

Microbial biofilms can be defined as multi-cellular aggregates adhering to a surface and embedded in an extracellular matrix (ECM). The nonpathogenic yeast, Saccharomyces cerevisiae, follows the common traits of microbial biofilms with cell-cell and cell-surface adhesion. S. cerevisiae is shown to produce an ECM and respond to quorum sensing, and multi-cellular aggregates have lowered susceptibility to antifungals. Adhesion is mediated by a family of cell surface proteins of which Flo11 has been shown to be essential for biofilm development. FLO11 expression is regulated via a number of regulatory pathways including the protein kinase A and a mitogen-activated protein kinase pathway. Advanced genetic tools and resources have been developed for S. cerevisiae including a deletion mutant-strain collection in a biofilm-forming strain background and GFP-fusion protein collections. Furthermore, S. cerevisiae biofilm is well applied for confocal laser scanning microscopy and fluorophore tagging of proteins, DNA and RNA. These techniques can be used to uncover the molecular mechanisms for biofilm development, drug resistance and for the study of molecular interactions, cell response to environmental cues, cell-to-cell variation and niches in S. cerevisiae biofilm. Being closely related to Candida species, S. cerevisiae is a model to investigate biofilms of pathogenic yeast.

Characterization of the archaeal community fouling a membrane bioreactor

“…Additionally, fungal organisms, such as Saccharomyces sp. and Cryptococcus sp., are also present in both the anoxic and aerobic sludge and form biofilms on the MBR membranes (Ravi et al, 2009;Bojsen et al, 2012).…”

Architecture and Biosynthesis of the Saccharomyces cerevisiae Cell Wall

“…Some mannoproteins have or are predicted to have enzymatic activity as hydrolases or crosslinkers; others may have structural roles or mediate "social activity" by serving as mating agglutinins or flocculins. Among the latter, Flo1 and Flo11 promote formation of extensive mats of cells, or biofilms (Reynolds and Fink 2001;Beauvais et al 2009;Bojsen et al 2012).…”

“…However, activation of individual FLO genes confers the ability to flocculate (Guo et al 2000;Van Mulders et al 2009). Flo11/Muc1, a diverged Flo protein (Lambrechts et al 1996;Lo and Dranginis 1996), is not involved in flocculation, but is required for pseudohypha formation by diploids, invasion of agar by haploids, and biofilm development (Lo and Dranginis 1998;Guo et al 2000;Reynolds and Fink 2001;Dranginis et al 2007;Bojsen et al 2012).…”

Global Regulation of a Differentiation MAPK Pathway in Yeast

“…During filamentous growth, major changes occur to cell polarity (Gimeno et al 1992;Roberts and Fink 1994;Pruyne and Bretscher 2000;Cullen and Sprague 2002;Bi and Park 2012), cell-cycle progression (Kron et al 1994;Edgington et al 1999), and cell adhesion (Lambrechts et al 1996;Lo and Dranginis 1998;Guo et al 2000), which results in formation of branched chains of interconnected invasive filaments. Filamentous cells form complex communities during biofilm formation (Reynolds and Fink 2001;Verstrepen and Klis 2006;Bojsen et al 2012). Many fungal species undergo filamentous growth.…”