Sulfate-reducing prokaryotes in mangrove wetlands: diversity and role in driving element coupling

Abstract:

Mangrove ecosystems are important coastal wetlands with highly efficient nutrient dynamics in the tropics and subtropics, and the hot zones driving the cycling of elements such as carbon, nitrogen, and sulfur. Sulfate-reducing prokaryotes (SRPs), one of the oldest microbial life forms on Earth, play a key role in driving early geological evolution and modern biogeochemical cycles of the Earth, while their role in mangrove wetlands remains to be studied. Only by fully understanding the processes and characteristics of the element biogeochemical cycles that SRPs participate in mangrove ecosystems can we capture the key aspects and clarify the coupling mechanisms. The development of bioinformatics has led to the discovery of more and more uncultured SRPs. In this paper, we systematically summarized the classification of sulfate-reducing bacteria and expand the taxa of SRPs based on the Genome Taxonomy Database prokaryotic genomes. We then introduced the distribution of SRPs in mangroves at home and abroad in recent years and the factors affecting the distribution to reveal the horizontal distribution diversity of SRPs in mangrove ecosystems. Further, we expounded the role of SRPs in the intertwined cycles of carbon, nitrogen, sulfur, and iron in mangrove wetlands, with emphasis on the molecular processes of SRPs in the sulfur cycle, especially dissimilatory sulfate reduction. Finally, we made an outlook on the future research directions of SRPs, aiming to provide references for further research on the element biogeochemical cycling and coupling driven by SRPs.