Diverse quorum sensing systems regulate microbial communication and biogeochemical processes in deep-sea cold seeps

Abstract

Quorum sensing is a fundamental chemical communication mechanism that enables microorganisms to coordinate behavior and adapt to environmental conditions. In deep-sea cold seep ecosystems, where diverse microbial communities thrive, quorum sensing is likely a key mechanism driving microbial interactions. However, the distribution, mechanisms, and ecological roles of quorum sensing in cold seeps remain poorly understood. To address this, we analyzed 173 metagenomes, 33 metatranscriptomes, and 18 metabolomes from 17 global cold seep sites. We identified 299,355 quorum sensing genes from the seep non-redundant gene catalog, representing 34 gene types across six quorum sensing systems, with distribution patterns influenced by sediment depth and seep type. These quorum sensing genes were present in 3,576 metagenome-assembled genomes from 12 archaeal and 108 bacterial phyla, revealing a complex network of intraspecies and interspecies communication. Microbial groups involved in key metabolic processes, such as sulfate-reducing bacteria, anaerobic methanotrophic archaea, diazotrophs and organohalide reducers, were extensively regulated by quorum sensing, influencing biogeochemical cycles of carbon, nitrogen, and sulfur. Phylogenetic analysis and protein domain identification highlighted the functional roles of key quorum sensing-related proteins (e.g., PDEs, CahR, RpfC/G and LuxR) in modulating microbial behaviors, such as motility and chemotaxis. Heterologous expression and metabolomic profiling further confirmed the activity of representative LuxI-R pairs and identified inhibitors of quorum sensing in cold seep sediments. Overall, these findings highlight complexity and significance of quorum sensing in microbial interactions, ecological adaptation, and biogeochemical cycling within cold seep ecosystems, advancing our understanding of microbial communication in the deep biosphere.