Fungal biofilm formation and quorum sensing: Regulatory mechanisms and control strategies.

Biofilm is a specialized communal mode of microbial existence, composed of self-produced extracellular polymeric substances including polysaccharides, proteins, lipids, and other macromolecules. Its formation typically proceeds through five sequential stages: adsorption, adhesion, formation of microcolonies, maturation, and dispersion. Once established, biofilms significantly enhance microbial environmental adaptability, interspecies competitiveness, and antimicrobial resistance compared to their planktonic counterparts. However, research on fungal biofilms lags considerably behind that on bacterial biofilms. Quorum sensing (QS) is a cell-to-cell communication mechanism in microbes, and biofilm development is tightly linked to QS systems. Fungal quorum sensing molecules (QSMs) are particularly complex and include self-secreted pheromones, extracellular signaling molecules (e.g., farnesol and tyrosol), components of the cAMP/PKA signaling pathway, and environmental cues such as CO₂ concentration. These QSMs collectively regulate fungal biofilm formation. This review provides a comprehensive summary of recent advances in understanding the development of fungal biofilms, the role of QSMs, and quorum quenching strategies. Additionally, it offers a comparative analysis with bacterial biofilms. The overarching goal is to furnish theoretical insights for the effective control of pathogenic biofilms and to facilitate the exploration of fungal QS systems.