Heterotrophic activity, primarily driven by sulfate-reducing prokaryotes, has traditionally been linked to nitrogen fixation in the root zone of coastal marine plants, leaving the role of chemolithoautotrophy in this process unexplored. The researchers show that sulfur oxidation coupled to nitrogen fixation is a previously overlooked process providing nitrogen to coastal marine macrophytes. In their study, they recovered 239 metagenome-assembled genomes from a salt marsh dominated by the foundation plant Spartina alterniflora, including diazotrophic sulfate-reducing and sulfur-oxidizing bacteria. Based on the findings, the researchers propose that the symbiosis between S. alterniflora and sulfur-oxidizing bacteria is key to ecosystem functioning of coastal salt marshes. The study's co-authors include School of Biological Sciences researchers: Jose Louis Rolando, Maxim Kolton, Tianze Song, Roth Conrad, Y. Liu, P. Pinamang, Professor and Associate Chair of Research Joel Kostka, and Professor Kostas Konstantinidis. (Konstantinidis is also professor in the School of Civil and Environmental Engineering.)