Analysis and engineering of quorum sensing-based communications between bacteria and fungi.

Bacteria and fungi ubiquitously coexist, with their interactions critically influencing human health and industrial processes. Quorum sensing (QS) is a core regulatory mechanism that enables density-dependent coordination and phenotypic responses across these two kingdoms. While bacteria and fungi utilize their respective QS systems to engage in competitive or cooperative interactions to enhance their environmental adaptability, the current understanding of QS-based communications between them remains scattered, and a systematic summary of this field is still lacking. In this review, we examine the intricate dialog between bacteria and fungi, focusing on its role in microbial network assembly and ecosystem function, to provide a comprehensive analysis and engineering perspective on QS-based cross-kingdom communication. Specifically, we will first briefly delineate the core architecture of bacterial and fungal QS systems and the phenotypes they govern. Then, we will analyze QS-based interactions across diverse environments between different bacteria and fungi, categorizing natural QS interactions based on various phenotypes, including biofilm co-assembly and metabolic complementation. We further compare and analyze synthetic biology strategies, including promoter engineering and directed evolution of QS regulatory components, for reprogramming bacterial-fungal interactions and their applications. By synthesizing and contrasting these natural paradigms with synthetic designs, we provide a blueprint for achieving modular control over bacterial-fungal communities in diverse environments. Finally, by outlining persistent challenges and future trends, we aim to propel this field forward, enabling the deciphering of complex microbial interactions and ultimately increasing our capacity to engineer microbial consortia for diverse applications.