Heterogeneous nitrogen fixation rates confer energetic advantage and expanded ecological niche of unicellular diazotroph populations.

ABSTRACT: Nitrogen fixing plankton provide nitrogen to fuel marine ecosystems and biogeochemical cycles but the factors that constrain their growth and habitat remain poorly understood. Here we investigate the importance of metabolic specialization in unicellular diazotroph populations, using laboratory experiments and model simulations. In clonal cultures of Crocosphaera watsonii and Cyanothece sp. spiked with ¹⁵N₂, cellular ¹⁵N enrichment developed a bimodal distribution within colonies, indicating that N₂ fixation was confined to a subpopulation. In a model of population metabolism, heterogeneous nitrogen (N₂) fixation rates substantially reduce the respiration rate required to protect nitrogenase from O₂. The energy savings from m

SUBMITTER: Masuda T 

PROVIDER: S-EPMC7156374 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature