Abstract
Bacteria play a crucial role in marine biogeochemistry by releasing, consuming and transforming organic matter. Far from being isolated entities, bacteria are involved in numerous cell–cell interactions. Among such interactions, quorum sensing (QS) allows bacteria to operate in unison, synchronizing their actions through chemical communication. This review aims to explore and synthesize our current knowledge of the involvement of QS in the regulation of bacterial processes that ultimately impact marine biogeochemical cycles. We first describe the principles of QS communication and the renewed interest in its study in marine environments. Second, we highlight that the microniches where QS is most likely to occur due to their high bacterial densities are also hotspots of bacterially mediated biogeochemical transformations. Many bacterial groups colonizing these microniches harbor various QS systems. Thereafter, we review relevant QS-regulated bacterial processes in marine environments, building on research performed in both complex marine assemblages and isolated marine bacteria. QS pathways have been shown to directly regulate organic matter degradation, carbon allocation and nutrient acquisition but also to structure the community composition by mediating colonization processes and microbial interactions. Finally, we discuss current limitations and future perspectives to better characterize the link between QS expression and the bacterial mediation of biogeochemical cycles. The picture drawn by this review highlights QS as one of the pivotal mechanisms impacting microbial composition and functions in the oceans, paving the way for future research to better constrain its impact on marine biogeochemical cycles.
Highlights
IntroductionHeterotrophic prokaryotes degrade up to 50% of the carbon (C) fixed by marine primary producers (Azam et al, 1983) and allow its reinjection to higher trophic levels through the quorum sensing (QS) Impacts Biogeochemical Cycles in the Ocean microbial loop (Pomeroy, 1974; Azam et al, 1983)
Cell–cell communication systems are increasingly being studied in marine environments, where they allow prokaryotes to cooperate with or compete against each other, especially in dense microniches such as marine aggregates, microbial mats and the microalgal phycosphere
QSbased regulations may be important for marine biogeochemical cycles, as they are involved in many ecologically relevant bacterial processes
Summary
Heterotrophic prokaryotes degrade up to 50% of the carbon (C) fixed by marine primary producers (Azam et al, 1983) and allow its reinjection to higher trophic levels through the QS Impacts Biogeochemical Cycles in the Ocean microbial loop (Pomeroy, 1974; Azam et al, 1983) In doing so, they remineralize nutrients that support the growth of primary producers (Azam and Malfatti, 2007; Pomeroy, 2007). As DOM contains compounds ranging from low to high molecular weight, bacteria implement different strategies to exploit them Some, such as Rhodobacterales, specialize in the uptake of small compounds that can be directly incorporated into the cells (Landa et al, 2017; FerrerGonzález et al, 2021). A third widespread strategy was recently discovered: “selfish” bacteria can bind polysaccharides on their cell surface and uptake the partially degraded products into their periplasmic space, resulting in a minimal diffusive loss of the substrates to other cells (Reintjes et al, 2017, 2019)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
