Nitrogen-fixing organisms are of importance to the environment, providing bioavailable nitrogen to the biosphere. Quantitative models have been used to complement the laboratory experiments and in situ measurements, where such evaluations are difficult or costly. Here, we review the current state of the quantitative modeling of nitrogen-fixing organisms and ways to enhance the bridge between theoretical and empirical studies.

Department of Earth Atmospheric and Planetary Sciences Massachusetts Institute of Technology Cambridge MA USA

Institute of Microbiology The Czech Academy of Sciences Opatovický mlýn Třeboň Czech Republic

School of Oceanography University of Washington Seattle WA USA

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Gruber N., Galloway J.N. An Earth-system perspective of the global nitrogen cycle. Nature. 2008;451:293–296. PubMed

Sohm J.A., Webb E.A., Capone D.G. Emerging patterns of marine nitrogen fixation. Nat Rev Microbiol. 2011;9:499–508. PubMed

Zehr J.P., Capone D.G. Changing perspectives in marine nitrogen fixation. Science. 2020;368:eaay9514. PubMed

Vitousek P.M., Cassman K., Cleveland C., Crews T., Field C.B., Grimm N.B. Towards an ecological understanding of biological nitrogen fixation. Biogeochemistry. 2002;57(58):1–45.

van Rhijn P., Vanderleyden J. The Rhizobium-plant symbiosis. FEMS Miccrobiol Rev Rev. 1995;59:124–142. PubMed PMC

Patriarca E.J., Tatè R., Iaccarino M. Key role of bacterial NH4+ metabolism in Rhizobium-plant symbiosis. Microbiol Mol Biol Rev. 2002;66:203–222. PubMed PMC

Herridge D.F., Peoples M.B., Boddey R.M. Global inputs of biological nitrogen fixation in agricultural systems. Plant Soil. 2008;311:1–18.

Bohlool B.B., Ladha J.K., Garrity D.P., Georg T. Biological nitrogen fixation for sustainable agriculture: a perspective. Plant Soil. 1992;141:1–11.

Noar J.D., Bruno-Bárcena J.M. Azotobacter vinelandii: the source of 100 years of discoveries and many more to come. Microbiol (United Kingdom) 2018;164:421–436. PubMed

Peoples M.B., Herridge D.F., Ladha J.K. Biological nitrogen fixation: an efficient source of nitrogen for sustainable agricultural production? Plant Soil. 1995;174:3–28.

Karl D., Letelier R., Tupas L., Dore J., Christian J., Hebel D. The role of nitrogen fixation in biogeochemical cycling in the subtropical North Pacific Ocean. Nature. 1997;388:533–538.

Singh A., Gandhi N., Ramesh R. Surplus supply of bioavailable nitrogen through N2 fixation to primary producers in the eastern Arabian Sea during autumn. Cont Shelf Res. 2019;181:103–110.

Kuypers M.M.M., Marchant H.K., Kartal B. The microbial nitrogen-cycling network. Nat Rev Microbiol. 2018;16:263–276. PubMed

Karl D.M., Church M.J., Dore J.E., Letelier R.M., Mahaffey C. Predictable and efficient carbon sequestration in the North Pacific Ocean supported by symbiotic nitrogen fixation. PNAS. 2012;109:1842–1849. PubMed PMC

Shiozaki T., Bombar D., Riemann L., Sato M., Hashihama F., Kodama T. Linkage between dinitrogen fixation and primary production in the oligotrophic South Pacific Ocean. Global Biogeochem Cycles. 2018;32:1028–1044.

Berg J.M., Tymoczko J.L., Stryer L. 7th edition. and Company:; New York: 2010. Biochemistry.

Michal G. Wiley & Spektrum; Heidelberg: 1999. Biochemical pathways: an atlas of biochemistry and molecular biology.

Lengeler J.W., Drews G., Schlegel H.G. Thieme; Stuttgart: 1999. Biology of the prokaryotes.

Madigan MT, Martinko JM, Parker J (2000.) Brock Biology of Microorganisms. 9th edition. Prentice-Hall, inc.: Upper Saddle River, New jersey.

Jungermann K., Kirchniawy H., Katz N., Thauer R.K. NADH, a physiological electron donor in clostridial nitrogen fixation. FEBS Lett. 1974;43:203–206. PubMed

Chen Y.-P., Yoch D.C. Reconstitution of the electron transport system that couples formate oxidation to nitrogenase in Methylosinus trichosporium OB3b. J Gen Microbiol. 1988;134:3123–3128.

Klucas R.V., Evans H.J. An electron donor system for nitrogenase-dependent acetylene reduction by extracts of soybean nodules. Plant Physiol. 1968;43:1458–1460. PubMed PMC

Seefeldt L.C., Hoffman B.M., Dean D.R. Mechanism of mo-dependent nitrogenase. Annu Rev Biochem. 2009;78:701–722. PubMed PMC

Seefeldt L.C., Yang Z.Y., Lukoyanov D.A., Harris D.F., Dean D.R., Raugei S. Reduction of substrates by nitrogenases. Chem Rev. 2020;120:5082–5106. PubMed PMC

Capone DG (1988.) Benthic nitrogen fixation. In: Blackburn, T.H. and Sorensen, J., eds. Nitrogen Cycling in Coastal Marine Environments. pp. 85–123.

Bombar D., Paerl R.W., Riemann L. Marine non-cyanobacterial diazotrophs: moving beyond molecular detection. Trends Microbiol. 2016;24:916–927. PubMed

Inomura K., Bragg J., Riemann L., Follows M.J. A quantitative model of nitrogen fixaion in the presence of ammonium. PLoS ONE. 2018;13 PubMed PMC

Martínez-Pérez C., Mohr W., Löscher C.R., Dekaezemacker J., Littmann S., Yilmaz P. The small unicellular diazotrophic symbiont, UCYN-A, is a key player in the marine nitrogen cycle. Nat Microbiol. 2016;1:1–7. PubMed

Zehr JP, Shilova IN, Farnelid HM, Muñoz-Maríncarmen M del C, Turk-Kubo KA (2016) Unusual marine unicellular symbiosis with the nitrogen-fixing cyanobacterium UCYN-A. Nat Microbiol. 2: 16214. PubMed

Udvardi M., Poole P.S. Transport and metabolism in legume-rhizobia symbioses. Annu Rev Plant Biol. 2013;64:781–805. PubMed

Nieves-Morión M., Flores E., Foster R.A. Predicting substrate exchange in marine diatom-heterocystous cyanobacteria symbioses. Environ Microbiol. 2020;22:2027–2052. PubMed

Rai A.N., Bergman B. Cyanobacterium-plant symbiosis. New Phytol. 2000;147:449–481. PubMed

Berman-Frank I., Cullen J.T., Shaked Y., Sherrell R.M., Falkowski P.G. Iron availability, cellular iron quotas, and nitrogen fixation in Trichodesmium. Limnol Oceanogr. 2001;46:1249–1260.

Ward B.A., Dutkiewicz S., Moore C.M., Follows M.J. Iron, phosphorus, and nitrogen supply ratios define the biogeography of nitrogen fixation. Limnol Oceanogr. 2013;58:2059–2075.

Fu F.-X., Mulholland M.R., Garcia N.S., Beck A., Bernhardt P.W., Warner M.E. Interactions between changing pCO2, N2 fixation, and Fe limitation in the marine unicellular cyanobacterium Crocosphaera. Limnol Oceanogr. 2008;53:2472–2484.

Sañudo-Wilhelmy S.A., Kustka A.B., Gobler C.J., Hutchins D.A., Yang M., Lwiza K. Phosphorus limitation of nitrogen fixation by Trichodesmium in the central Atlantic Ocean. Nature. 2001;411:66–69. PubMed

Crews T.E., Farrington H., Vitousek P.M. Changes in asymbiotic, heterotrophic nitrogen fixation on leaf litter of Metrosideros polymorpha with long-term ecosystem development in Hawaii. Ecosystems. 2000;3:386–395.

Vitousek P.M., Porder S., Houlton B.Z., Chadwick O.A. Terrestrial phosphorus limitation: mechanisms, implications, and nitrogen-phosphorus interactions. Ecol Appl. 2010;20:5–15. PubMed

Eady R.R. Structure-function relationships of alternative nitrogenases. Chem Rev. 1996;96:3013–3030. PubMed

Darnajoux R., Magain N., Renaudin M., Lutzoni F., Bellenger J.P., Zhang X. Molybdenum threshold for ecosystem scale alternative vanadium nitrogenase activity in boreal forests. PNAS. 2019;116:24682–24688. PubMed PMC

Zhang X., Ward B.B., Sigman D.M. Global nitrogen cycle: critical enzymes, organisms, and processes for nitrogen budgets and dynamics. Chem Rev. 2020;120:5308–5351. PubMed

Zhang X, McRose DL, Darnajoux R, Bellenger JP, Morel FMM, L KAM (2016) Alternative nitrogenase activity in the environment and nitrogen cycle implications. Biogeochem Lett. 127: 189–198.

Dyhrman S.T., Haley S.T. Phosphorus scavenging in the unicellular marine diazotroph Crocosphaera watsonii. Appl Environ Microbiol. 2006;72:1452–1458. PubMed PMC

Polyviou D., Baylay A.J., Hitchcock A., Robidart J., Moore C.M., Bibby T.S. Desert dust as a source of iron to the globally important diazotroph Trichodesmium. Front Microbiol. 2018;8:2683. PubMed PMC

Hopkinson B.M., Barbeau K.A. Iron transporters in marine prokaryotic genomes and metagenomes. Environ Microbiol. 2012;14:114–128. PubMed

Dyhrman S.T., Chappell P.D., Haley S.T., Moffett J.W., Orchard E.D., Waterbury J.B. Phosphonate utilization by the globally important marine diazotroph Trichodesmium. Nature. 2006;439:68–71. PubMed

Rubin M., Berman-Frank I., Shaked Y. Dust-and mineral-iron utilization by the marine dinitrogen-fixer Trichodesmium. Nat Geosci. 2011;4:529–534.

Benavides M., Duhamel S., Van Wambeke F., Shoemaker K.M., Moisander P.H., Salamon E. Dissolved organic matter stimulates N2 fixation and nifH gene expression in Trichodesmium. FEMS Microbiol Lett. 2020;367:1–8. PubMed

Achilles K.M., Church T.M., Wilhelm S.W., Luther G.W., Hutchins D.A. Bioavailability of iron to Trichodesmium colonies in the western subtropical Atlantic Ocean. Limnol Oceanogr. 2003;48:2250–2255.

Basu S., Gledhill M., de Beer D., Prabhu Matondkar S.G., Shaked Y. Colonies of marine cyanobacteria Trichodesmium interact with associated bacteria to acquire iron from dust. Commun Biol. 2019;2:1–8. PubMed PMC

Roe K.L., Barbeau K.A. Uptake mechanisms for inorganic iron and ferric citrate in Trichodesmium erythraeum IMS101. Metallomics. 2014;6:2042–2051. PubMed

Hopkinson B.M., Morel F.M.M. The role of siderophores in iron acquisition by photosynthetic marine microorganisms. Biometals. 2009;22:659–669. PubMed

Inomura K., Bragg J., Follows M.J. A quantitative analysis of the direct and indirect costs of nitrogen fixation: a model based on Azotobacter vinelandii. ISME J. 2017;11:166–175. PubMed PMC

Gallon J.R. The oxygen sensitivity of nitrogenase: a problem for biochemists and micro-organisms. Trends Biochem Sci. 1981;6:19–23.

Dalton H., Postgate J.R. Effect of oxygen on growth of Azotobacter chroococcum in batch and continuous cultures. J Gen Microbiol. 1968;54:463–473. PubMed

Saito M.A., Bertrand E.M., Dutkiewicz S., Bulygin V.V., Moran D.M., Monteiro F.M. Iron conservation by reduction of metalloenzyme inventories in the marine diazotroph Crocosphaera watsonii. PNAS. 2011;108:2184–2189. PubMed PMC

Mohr W., Intermaggio M.P., LaRoche J. Diel rhythm of nitrogen and carbon metabolism in the unicellular, diazotrophic cyanobacterium Crocosphaera watsonii WH8501. Environ Microbiol. 2010;12:412–421. PubMed

Dron A., Rabouille S., Claquin P., Roy B., Talec A., Sciandra A. Light-dark (12:12) cycle of carbon and nitrogen metabolism in Crocosphaera watsonii WH8501: relation to the cell cycle. Environ Microbiol. 2012;14:967–981. PubMed

Reddy K.J., Haskell J.B., Sherman D.M., Sherman L.A. Unicellular, aerobic nitrogen-fixing cyanobacteria of the genus Cyanothece. J Bacteriol. 1993;175:1284–1292. PubMed PMC

Berman-Frank I., Lundgren P., Falkowski P. Nitrogen fixation and photosynthetic oxygen evolution in cyanobacteria. Res Microbiol. 2003;154:157–164. PubMed

Wilson S.T., Tozzi S., Foster R.A., Ilikchyan I., Kolber Z.S., Zehr J.P. Hydrogen cycling by the unicellular marine diazotroph Crocosphaera watsonii strain WH8501. Appl Environ Microbiol. 2010;76:6797–6803. PubMed PMC

Popa R., Weber P.K., Pett-Ridge J., Finzi J.A., Fallon S.J., Hutcheon I.D. Carbon and nitrogen fixation and metabolite exchange in and between individual cells of Anabaena oscillarioides. ISME J. 2007;1:354–360. PubMed

Kellar P.E., Goldman C.R. A comparative study of nitrogen fixation by the Anabaena-Azolla symbiosis and free-living populations of Anabaena spp. in Lake Ngahawa. New Zealand Oecologia. 1979;43:269–281. PubMed

Fay P. Oxygen relations of nitrogen fixation in cyanobacteria. Microbiol Rev. 1992;56:340–373. PubMed PMC

Flores E., Herrero A. Compartmentalized function through cell differentiation in filamentous cyanobacteria. Nat Rev Microbiol. 2010;8:39–50. PubMed

Staal M., Meysman F.J.R., Stal L.J. Temperature excludes N2-fixing heterocystous cyanobacteria in the tropical oceans. Nature. 2003;425:504–507. PubMed

MacDougall J.D.B., McCabe M. Diffusion coefficient of oxygen through tissues. Nature. 1967;215:1173–1174. PubMed

Robertson J.E., Watson A.J., Langdon C., Ling R.D., Wood J.W. Diurnal variation in surface pCO2 and O2 at 60°N, 20°W in the North Atlantic. Deep-Sea Res Part II. 1993;40:409–422.

Yates K.K., Dufore C., Smiley N., Jackson C., Halley R.B. Diurnal variation of oxygen and carbonate system parameters in Tampa Bay and Florida Bay. Mar Chem. 2007;104:110–124.

Fransson A., Chierici M., Anderson L.G. Diurnal variability in the oceanic carbon dioxide system and oxygen in the Southern Ocean surface water. Deep-Sea Res Part II. 2004;51:2827–2839.

Russel E.J., Appleyard A. The atmosphere of the soil: its composition and the causes of variation. J Agric Sci. 1915;7:1–48.

Sabra W., Zeng A.P., Lünsdorf H., Deckwer W.D. Effect of oxygen on formation and structure of Azotobacter vinelandii alginate and its role in protecting nitrogenase. Appl Environ Microbiol. 2000;66:4037–4044. PubMed PMC

Walsby A.E. Cyanobacterial heterocysts: terminal pores proposed as sites of gas exchange. Trends Microbiol. 2007;15:340–349. PubMed

Poole R.K., Hill S. Respiratory protection of nitrogenase activity in Azotobacter vinelandii-Roles of the terminal oxidases. Biosci Rep. 1997;17:303–317. PubMed

Inomura K., Deutsch C., Wilson S.T., Masuda T., Lawrenz E., Bučinská L. Quantifying oxygen management and temperature and light dependencies of nitrogen fixation by Crocosphaera watsonii. mSphere. 2019;4 e00531-19. PubMed PMC

Howarth R.W., Marino R., Lane J., Cole J.J. Nitrogen fixation in freshwater, estuarine, and marine ecosystems. 1 Rates and importance. Limnol Oceanogr. 1988;33:669–687.

Gier J., Sommer S., Löscher C.R., Dale A.W., Schmitz R.A., Treude T. Nitrogen fixation in sediments along a depth transect through the Peruvian oxygen minimum zone. Biogeosciences. 2016;13:4065–4080.

Fernandez C., Farı L., Ulloa O. Nitrogen fixation in denitrified marine waters. PLoS ONE. 2011;6 PubMed PMC

Tjepkema J.D., Yocum C.S. Measurement of oxygen partial pressure within soybean nodules byoxygen microelectrodes. Planta (Berl) 1974;119:351–360. PubMed

Tjepkema J.D. Oxygen concentration within the nitrogen-fixing root nodules of Myrica gale L. Am J Bot. 1983;70:59–63. PubMed

Wang D., Xu A., Elmerich C., Ma L.Z. Biofilm formation enables free-living nitrogen-fixing rhizobacteria to fix nitrogen under aerobic conditions. ISME J. 2017;11:1602–1613. PubMed PMC

Castillo T., López I., Flores C., Segura D., García A., Galindo E. Oxygen uptake rate in alginate producer (algU+) and nonproducer (algU-) strains of Azotobacter vinelandii under nitrogen-fixation conditions. J Appl Microbiol. 2018;125:181–189. PubMed

Inomura K., Wilson S.T., Deutsch C. Mechanistic model for the coexistence of nitrogen fixation and photosynthesis in marine Trichodesmium. mSystems. 2019;4:e00210–19. PubMed PMC

Eichner M., Thoms S., Rost B., Mohr W., Ahmerkamp S., Ploug H. N2 fixation in free-floating filaments of Trichodesmium is higher than in transiently suboxic colony microenvironments. New Phytol. 2019;222:852–863. PubMed PMC

Großkopf T., LaRoche J. Direct and indirect costs of dinitrogen fixation in Crocosphaera watsonii WH8501 and possible implications for the nitrogen cycle. Front Microbiol. 2012;3:236. PubMed PMC

Tang W., Wang S., Fonseca-Batista D., Dehairs F., Gifford S., Gonzalez A.G. Revisiting the distribution of oceanic N 2 fixation and estimating diazotrophic contribution to marine production. Nat Commun. 2019;10:1–10. PubMed PMC

Tang W., Li Z., Cassar N. Machine learning estimates of global marine nitrogen fixation. J Geophys Res Biogeosciences. 2019;124:717–730.

Luo Y.-W., Lima I.D., Karl D.M., Deutsch C.A., Doney S.C. Data-based assessment of environmental controls on global marine nitrogen fixation. Biogeosciences. 2014;11:691–708.

Cleveland C.C., Townsend A.R., Schimel D.S., Fisher H., Howarth R.W., Hedin L.O. Global patterns of terrestrial biological nitrogen (N2) fixation in natural ecosystems. Global Biogeochem Cycles. 1999;13:623–645.

Galloway J.N., Dentener F.J., Capone D.G., Boyer E.W., Howarth R.W., Seitzinger S.P. Nitrogen cycles: past, present, and future. Biogeochemistry. 2004;70:153–226.

Capone D.G., Zehr J.P., Paerl H.W., Bergman B., Carpenter E.J. Trichodesmium, a globally significant marine cyanobacterium. Science. 1997;276:1221–1229.

Zehr J.P. Nitrogen fixation by marine cyanobacteria. Trends Microbiol. 2011;19:162–173. PubMed

Mohr W., Großkopf T., Wallace D.W.R., LaRoche J. Methodological underestimation of oceanic nitrogen fixation rates. PLoS ONE. 2010;5 PubMed PMC

Minchin F.R., Witty J.F., Sheehy J.E., Müller M. A major error in the acetylene reduction assay: decreases in nodular nitrogenase activity under assay conditions. J Exp Bot. 1983;34:641–649.

Minchin F.R., Sheehy J.E., Witty J.F. Further errors in the acetylene reduction assay: effects of plant disturbance. J Exp Bot. 1986;37:1581–1591.

Witty JF, Minchin FR (1988) Measurement of nitrogen fixation by the acetylene reduction assay; myths and mysteries. In: Beck D.P., Materon L.A. (eds.) Nitrogen Fixation by Legumes in Mediterranean Agriculture. Developments in Plant and Soil Sciences, , vol 32. Springer, Dordrecht. : 331–344.

Lee K.K., Watanabe I. Problems of the acetylene reduction technique applied to water-saturated paddy soils. Appl Environ Microbiol. 1977;34:654–660. PubMed PMC

Grimaud G.M., Rabouille S., Dron A., Sciandra A., Bernard O. Modelling the dynamics of carbon – nitrogen metabolism in the unicellular diazotrophic cyanobacterium Crocosphaera watsonii WH8501, under variable light regimes. Ecol Modell. 2014;291:121–133.

Pahlow M., Dietze H., Oschlies A. Optimality-based model of phytoplankton growth and diazotrophy. Mar Ecol Prog Ser. 2013;489:1–16.

Resendis-Antonio O., Hernández M., Salazar E., Contreras S., Batallar G., Mora Y. Systems biology of bacterial nitrogen fixation: high-throughput technology and its integrative description with constraint-based modeling. BMC Syst Biol. 2011;5:120. PubMed PMC

Le Lin B, Sakoda A., Shibasaki R., Goto N., Suzuki M. Modelling a global biogeochemical nitrogen cycle in terrestrial ecosystems. Ecol Modell. 2000;135:89–110.

Wang Y.P., Houlton B.Z., Field C.B. A model of biogeochemical cycles of carbon, nitrogen, and phosphorus including symbiotic nitrogen fixation and phosphatase production. Global Biogeochem Cycles. 2007;21:1–15.

Menge D.N.L., Hedin L.O., Pacala S.W. Nitrogen and phosphorus limitation over long-term ecosystem development in terrestrial ecosystems. PLoS ONE. 2012;7 PubMed PMC

Stukel M.R., Coles V.J., Brooks M.T., Hood R.R. Top-down, bottom-up and physical controls on diatom-diazotroph assemblage growth in the Amazon River plume. Biogeosciences. 2014;11:3259–3278.

Fernández-Castro B., Pahlow M., Mouriño-Carballido B., Marañón E., Oschlies A. Optimality-based Trichodesmium diazotrophy in the North Atlantic subtropical gyre. J Plankton Res. 2016;38:946–963.

Monteiro F.M., Follows M.J., Dutkiewicz S. Distribution of diverse nitrogen fixers in the global ocean. Global Biogeochem Cycles. 2010;24:GB3017.

Weber T., Deutsch C. Local versus basin-scale limitation of marine nitrogen fixation. PNAS. 2014;111:8741–8746. PubMed PMC

Follett C.L., Dutkiewicz S., Karl D.M., Inomura K., Follows M.J. Seasonal resource conditions favor a summertime increase in North Pacific diatom–diazotroph associations. ISME J. 2018;12:1543–1557. PubMed PMC

Karl D.M., Church M.J. Microbial oceanography and the Hawaii Ocean Time-series programme. Nat Rev Microbiol. 2014;12:699–713. PubMed

Barton AD, Pershing AJ, Litchman E, Record NR, Edwards KF, Finkel Z V, et al. (2013) The biogeography of marine plankton traits. Ecol Lett. 16: 522–34 PubMed

Weber T.S., Deutsch C. Oceanic nitrogen reservoir regulated by plankton diversity and ocean circulation. Nature. 2012;489:419–422. PubMed

Tagliabue A., Aumount O., DeAth R., Dunne J.P., Dutkiewicz S., Galbraith E. How well do global ocen biogeochemistry models simulate dissolved iron distributions? Global Biogeochem Cycles. 2016;30:149–174.

Moore J.K., Doney S.C., Kleypas J.A., Glover D.M., Fung I.Y. An intermediate complexity marine ecosystem model for the global domain. Deep Sea Res II. 2002;49:403–462.

Moore J.K., Doney S.C., Lindsay K. Upper ocean ecosystem dynamics and iron cycling in a global three-dimensional model. Global Biogeochem Cycles. 2004;18:1–21.

Le Quéré C., Harrison S.P., Prentice I.C., Buitenhuis E.T., Aumont O., Bopp L. Ecosystem dynamics based on plankton functional types for global ocean biogeochemistry models. Glob Chang Biol. 2005;11:2016–2040.

Moore J.K., Lindsay K., Doney S.C., Long M.C., Misumi K. Marine ecosystem dynamics and biogeochemical cycling in the community earth system model [CESM1(BGC)]: comparison of the 1990s with the 2090s under the RCP4.5 and RCP8.5 scenarios. J Clim. 2013;26:9291–9312.

Laufkotter C., Vogt M., Gruber N., Aita-Noguchi M., Aumont O., Bopp L. Drivers and uncertainties of future global marine primary production in marine ecosystem models. Biogeosciences. 2015;12:6955–6984.

Monod J. The growth of bacterial cultures. Ann Rev Mar Sci. 1949;3:371–394.

Landolfi A., Dietze H., Koeve W., Oschlies A. Overlooked runaway feedback in the marine nitrogen cycle: the vicious cycle. Biogeosciences. 2013;10:1351–1363.

Moreno A.R., Martiny A.C. Ecological stoichiometry of ocean plankton. Ann Rev Mar Sci. 2018;10:43–69. PubMed

Inomura K., Omta A.W., Talmy D., Bragg J., Deutsch C., Follows M.J. A Mechanistic model of macromolecular allocation, elemental stoichiometry, and growth rate in phytoplankton. Front Microbiol. 2020;11:1–22. PubMed PMC

Omta A.W., Talmy D., Inomura K., Irwin A.J., Finkel Z.V., Sher D. Quantifying nutrient throughput and DOM production by algae in continuous culture. J Theor Biol. 2020;494 PubMed

Liefer J.D., Garg A., Fyfe M.H., Irwin A.J., Benner I., Brown C.M. The macromolecular basis of phytoplankton C:N: P under nitrogen starvation. Front Microbiol. 2019;10:763. PubMed PMC

Dutkiewicz S., Cermeno P., Jahn O., Follows M.J., Hickman A.A., Taniguchi D.A.A. Dimensions of marine phytoplankton diversity. Biogeosciences. 2020;17:609–634.

Landolfi A., Koeve W., Dietze H., Kähler P., Oschlies A. A new perspective on environmental controls of marine nitrogen fixation. Geophys Res Lett. 2015;42:4482–4489.

Tilman D. Princeton University Press; Princeton, NJ, USA: 1982. Resource competition and community structure. PubMed

Menge D.N.L., Levin S.A., Hedin L.O. Evolutionary tradeoffs can select against nitrogen fixation and thereby maintain nitrogen limitation. PNAS. 2008;105:1573–1578. PubMed PMC

Menge D.N.L., Levin S.A., Hedin L.O. Facultative versus obligate nitrogen fixation strategies and their ecosystem consequences. Am Nat. 2009;174:465–477. PubMed

Houlton B.Z., Wang Y.P., Vitousek P.M., Field C.B. A unifying framework for dinitrogen fixation in the terrestrial biosphere. Nature. 2008;454:327–330. PubMed

Le Lin B, Sakoda A., Shibasaki R., Suzuki M. A modelling approach to global nitrate leaching caused by anthropogenic fertilisation. Water Res. 2001;35:1961–1968. PubMed

Thornton P.E., Lamarque J.F., Rosenbloom N.A., Mahowald N.M. Influence of carbon-nitrogen cycle coupling on land model response to CO2 fertilization and climate variability. Global Biogeochem Cycles. 2007;21:GB4018.

Oleson K.W., Lawrence D.M., Bonan G.B., Drewniak B., Huang M., Koven C.D. Technical description of version 4.5 of the Community Land Model (CLM) NCAR Tech. 2013

Wieder W.R., Cleveland C.C., Lawrence D.M., Bonan G.B. Effects of model structural uncertainty on carbon cycle projections: biological nitrogen fixation as a case study. Environ Res Lett. 2015;10:44016.

Vitousek P.M., Field C.B. Ecosystem constraints to symbiotic nitrogen fixers: a simple model and its implications. Biogeochemistry. 1999;46:179–202.

Orth J.D., Thiele I., Palsson B.Ø. What is flux balance analysis? Nat Biotechnol. 2010;28:245–248. PubMed PMC

Schuster S., Fell D. Modeling and simulating metabolic networks. In: Lengauer T., editor. Bioinformatics: From Genomes to Therapies. Wiley-VCH; Weinheim: 2007. pp. 755–805.

Resendis-Antonio O., Reed J.L., Encarnación S., Collado-Vides J., Palsson B. Metabolic reconstruction and modeling of nitrogen fixation in Rhizobium etli. PLOS Comput Biol. 2007;3:1887–1895. PubMed PMC

Campos T.D., Zuñiga C., Passi A., Toro J.D., Tibocha-Bonilla J.D., Zepeda A. Modeling of nitrogen fixation and polymer production in the heterotrophic diazotroph Azotobacter vinelandii DJ. Metab Eng Commun. 2020;11 PubMed PMC

Schuster S., Fell D.A., Pfeiffer T. Is maximization of molar yield in metabolic networks favoured by evolution? J Theor Biol. 2008;252:497–504. PubMed

Singh D., Carlson R., Fell D., Poolman M. Modelling metabolism of the diatom Phaeodactylum tricornutum. Biochem Soc Trans. 2015;43:1182–1186. PubMed

Oberhardt M.A., Palsson B., Papin J.A. Applications of genome-scale metabolic reconstructions. Mol Syst Biol. 2009;5:1–15. PubMed PMC

Feist A.M., Palsson B. The growing scope of applications of genome-scale metabolic reconstructions using Escherichia coli. Nat Biotechnol. 2008;26:659–667. PubMed PMC

Raman K., Chandra N. Flux balance analysis of biological systems: applications and challenges. Brief Bioinform. 2009;10:435–449. PubMed

Felcmanová K, Lukeš M, Kotabová E, Lawrenz E, Halsey KH, Prášil O (2017) Carbon use efficiencies and allocation strategies in Prochlorococcus marinus strain PCC 9511 during nitrogen-limited growth. Photosynth Res. 134: 71–82. PubMed

Zavřel T., Faizi M., Loureiro C., Poschmann G., Stühler K., Sinetova M. Quantitative insights into the cyanobacterial cell economy. Elife. 2019;8 PubMed PMC

Jahn M., Vialas V., Karlsen J., Maddalo G., Edfors F., Forsström B. Growth of cyanobacteria is constrained by the abundance of light and carbon assimilation proteins. Cell Rep. 2018;25:478–486. PubMed

Gomez J.A., Höffner K., Barton P.I. DFBAlab: a fast and reliable MATLAB code for dynamic flux balance analysis. BMC Bioinf. 2014;15:1–10. PubMed PMC

Gomez J.A., Barton P.I. Metabolic Network Reconstruction and Modeling; Humana Press: New York. USA; NY: 2018. Dynamic flux balance analysis using DFBAlab; pp. 353–370.

Gardner J.J., Boyle N.R. The use of genome-scale metabolic network reconstruction to predict fluxes and equilibrium composition of N-fixing versus C-fixing cells in a diazotrophic cyanobacterium, Trichodesmium erythraeum. BMC Syst Biol. 2017;11:4. PubMed PMC

Follows M.J., Dutkiewicz S. Modeling diverse communities of marine microbes. Ann Rev Mar Sci. 2011;3:427–451. PubMed

Shuter B. A model of physiological adaptation in unicellular algae. J Theor Biol. 1979;78:519–552. PubMed

Hellweger F.L., Fredrick N.D., McCarthy M.J., Gardner W.S., Wilhelm S.W., Paerl H.W. Dynamic, mechanistic, molecular-level modelling of cyanobacteria: anabaena and nitrogen interaction. Environ Microbiol. 2016;18:2721–2731. PubMed

Nicholson D.P., Stanley R.H.R., Doney S.C. A phytoplankton model for the allocation of gross photosynthetic energy including the trade-offs of diazotroophy. J Geophys Res Biogeosciences. 2018;123:1796–1816.

Faizi M., Steuer R. Optimal proteome allocation strategies for phototrophic growth in a light-limited chemostat. Microb Cell Fact. 2019;18:165. PubMed PMC

Rittmann B.E., McCarty P.L. McGraw-Hill; New York, NY: 2001. Environmental biotechnology: principles and applications.

Inomura K., Masuda T., Gauglitz J.M. Active nitrogen fixation by Crocosphaera expands their niche despite the presence of ammonium – A case study. Sci Rep. 2019;9:15064. PubMed PMC

Bull A.T. The renaissance of continuous culture in the post-genomics age. J Ind Microbiol Biotechnol. 2010;37:993–1021. PubMed

Healey F.P. Interacting effects of light and nutrient limitation on the growth rate of Synechococcus linearis (Cyanophyceae) J Phycol. 1985;21:134–146.

Henley W.J. The past, present and future of algal continuous cultures in basic research and commercial applications. Algal Res. 2019;43

Nagai S., Aiba S. Reassessment of maintenance and energy uncoupling in the growth of Azotobacter vinelandii. J Gen Microbiol. 1972;73:531–538. PubMed

Kuhla J., Oelze J. Dependency of growth yield, maintenance and Ks-values on the disoolved oxygen concentration in continuous cultures of Azotobacter vinelandii. Arch Microbiol. 1988;149:509–514.

Bühler T., Sann R., Monter U., Dingier C., Kuhla J., Oelze J. Control of dinitrogen fixation in ammonium-assimilating cultures of Azotobacter vinelandii. Arch Microbiol. 1987;148:247–251.

Bühler T., Monter U., Sann R., Kuhla J., Dingier C., Oelze J. Control of respiration and growth yield in ammonium-assimilating cultures of Azotobacter vinelandii. Arch Microbiol. 1987;148:242–246.

García A., Ferrer P., Albiol J., Castillo T., Segura D., Peña C. Metabolic flux analysis and the NAD(P)H/NAD(P)+ ratios in chemostat cultures of Azotobacter vinelandii. Microb Cell Fact. 2018;17:10. PubMed PMC

Sessitsch A., Howieson J.G., Perret X., Antoun H., Martínez-Romero E. Advances in Rhizobium research. CRC Crit Rev Plant Sci. 2002;21:323–378.

González V., Santamaría R.I., Bustos P., Hernández-González I., Medrano-Soto A., Moreno-Hagelsieb G. The partitioned Rhizobium etli genome: genetic and metabolic redundancy in seven interacting replicons. PNAS. 2006;103:3834–3839. PubMed PMC

Kanehisa M., Goto S., Hattori M., Aoki-Kinoshita K.F., Itoh M., Kawashima S. From genomics to chemical genomics: new developments in KEGG. Nucleic Acids Res. 2006;34:D354–D357. PubMed PMC

Rai A.N. CRC Press, FL, USA; Boca Raton: 1990. Handbook of symbiotic cyanobacteria.

Kaplan D., Peters G.A. Interaction of carbon metabolism in the Azolla-Anabaena symbiosis. Symbiosis. 1988;6:53–68.

Peters G.A., Meeks J.C. The Azolla-Anabaena symbiosis: basic biology. Annu Rev Plant Physiol Mol Biol. 1989;40:193–210.

Fay P., Walsby A.E. Metabolic activities of isolated heterocysts of the blue-green alga Anabaena cylindrica. Nature. 1966;209:94–95. PubMed

Wilcox M., Mitchison G.J., Smith R.J. Pattern formation in the blue-green alga, Anabaena I Basic mechanisms. J Cell Sci. 1973;12:707–723. PubMed

Walsby A.E. The permeability of heterocysts to the gases nitrogen and oxygen. Proc R Soc London Ser B, Biol Sci. 1985;226:345–366.

Paerl Hans W. Role of heterotrophic bacteria in promoting N2 fixation by anabaena in aquatic habitats. Microb Ecol. 1978;4:215–231. PubMed

Wolk C.P., Ernst A., Elhai J. Heterocyst metabolism and development. In: Bryant D.A., editor. The Molecular Biology of Cyanobacteria. Kluwer Academic; Dordrecht: 1994.

Adams D.G. Heterocyst formation in cyanobacteria. Curr Opin Microbiol. 2000;3:618–624. PubMed

Nürnberg D.J., Mariscal V., Bornikoel J., Nieves-Morión M., Krauß N., Herrero A. Intercellular diffusion of a fluorescent sucrose analog via the septal junctions in a filamentous cyanobacterium. mBio. 2015;6 e02109-14. PubMed PMC

Hellweger F.L., Kravchuk E.S., Novotny V., Gladyshev M.I. Agent-based modeling of the complex life cycle of a cyanobacterium (Anabaena) in a shallow reservoir. Limnol Oceanogr. 2008;53:1227–1241.

Hellweger F.L. Resonating circadian clocks enhance fitness in cyanobacteria in silico. Ecol Modell. 2010;221:1620–1629.

Pinzon N.M., Ju L.K. Modeling culture profiles of the heterocystous N2-fixing cyanobacterium Anabaena flos-aquae. Biotechnol Prog. 2006;22:1532–1540. PubMed

Allard J.F., Hill A.L., Rutenberg A.D. Heterocyst patterns without patterning proteins in cyanobacterial filaments. Dev Biol. 2007;312:427–434. PubMed

Zhu M., Callahan S.M., Allen J.S. Maintenance of heterocyst patterning in a filamentous cyanobacterium. J Biol Dyn. 2010;4:621–633. PubMed

Brown A.I., Rutenberg A.D. A storage-based model of heterocyst commitment and patterning in cyanobacteria. Phys Biol. 2014;11 PubMed

Torres-Sánchez A., Gómez-Gardeñes J., Falo F. An integrative approach for modeling and simulation of heterocyst pattern formation in cyanobacteria filaments. PLOS Comput Biol. 2015;11:1–18. PubMed PMC

Ishihara J., Tachikawa M., Iwasaki H., Mochizuki A. Mathematical study of pattern formation accompanied by heterocyst differentiation in multicellular cyanobacterium. J Theor Biol. 2015;371:9–23. PubMed

Muñoz-garcía J., Ares S. Formation and maintenance of nitrogen-fixing cell patterns in filamentous cyanobacteria. PNAS. 2016;113:6218–6223. PubMed PMC

Bormans M., Condie S.A. Modelling the distribution of Anabaena and Melosira in a stratified river weir pool. Hydrobiologia. 1997;364:3–13.

Malatinszky D., Steuer R., Jones P.R. A comprehensively curated genome-scale two-cell model for the heterocystous cyanobacterium Anabaena sp. PCC 7120. Plant Physiol. 2017;173:509–523. PubMed PMC

Rabouille S., Staal M., Stal L.J., Soetaert K. Modeling the dynamic regulation of nitrogen fixation in the cyanobacterium Trichodesmium sp. Appl Environ Microbiol. 2006;72:3217–3227. PubMed PMC

Inomura K., Follett C.L., Masuda T., Eichner M., Prášil O., Deutsch C. Carbon transfer from the host diatom enables fast growth and high rate of N2 fixation by symbiotic heterocystous cyanobacteria. Plants. 2020;9:192. PubMed PMC

Masuda T., Inomura K., Takahata N., Shiozaki T., Sano Y., Deutsch C. Heterogeneous nitrogen fixation rates confer energetic advantage and expanded ecological niche of unicellular diazotroph populations. Commun Biol. 2020;3:172. PubMed PMC

Mulholland M.R., Bernhardt P.W. The effect of growth rate, phosphorus concentration, and temperature on N2 fixation, carbon fixation, and nitrogen release in continuous cultures of Trichodesmium IMS101. Limnol Oceanogr. 2005;50:839–849.

Coles V.J., Hood R.R., Pascual M., Capone D.G. Modeling the impact of Trichodesmium and nitrogen fixation in the Atlantic ocean. J Geophys Res C Ocean. 2004;109:C06007.

Dutheil C., Aumont O., Gorguès T., Lorrain A., Bonnet S., Rodier M. Modelling N2 fixation related to Trichodesmium sp.: driving processes and impacts on primary production in the tropical Pacific Ocean. Biogeosciences. 2018;15:4333–4352.

Luo Y.W., Shi D., Kranz S.A., Hopkinson B.M., Hong H., Shen R. Reduced nitrogenase efficiency dominates response of the globally important nitrogen fixer Trichodesmium to ocean acidification. Nat Commun. 2019;10:1521. PubMed PMC

Moisander P.H., Beinart R.A., Hewson I., White A.E., Johnson K.S., Carlson C.A. Unicellular cyanobacterial distributions broaden the oceanic N2 fixation domain. Science. 2010;327:1512–1514. PubMed

Vu T.T., Stolyar S.M., Pinchuk G.E., Hill E.A., Kucek L.A., Brown R.N. Genome-scale modeling of light-driven reductant partitioning and carbon fluxes in diazotrophic unicellular cyanobacterium Cyanothece sp. ATCC 51142. PLOS Comput Biol. 2012;8 PubMed PMC

Shi T., Ilikchyan I., Rabouille S., Zehr J.P. Genome-wide analysis of diel gene expression in the unicellular N2-fixing cyanobacterium Crocosphaera watsonii WH 8501. ISME J. 2010;4:621–632. PubMed

Mareš J., Johansen J.R., Hauer T., Zima J., Ventura S., Cuzman O. Taxonomic resolution of the genus Cyanothece (Chroococcales, Cyanobacteria), with a treatment on Gloeothece and three new genera, Crocosphaera, Rippkaea, and Zehria. J Phycol. 2019;55:578–610. PubMed

Hilton J.A., Foster R.A., James Tripp H., Carter B.J., Zehr J.P., Villareal T.A. Genomic deletions disrupt nitrogen metabolism pathways of a cyanobacterial diatom symbiont. Nat Commun. 2013;4:1767. PubMed PMC

Villareal T.A. Marine nitrogen fixing diatom - cyanobacteria symbioses. In: Carpenter E.J., Capone D.G., Rueter J.G., editors. Marine Pelagic Cyanobacteria: Trichodesmium and Other Diazotrophs. Kluwer Academic Publishers; The Neatherlands: 1992.

Schneegurt M.A., Sherman D.M., Nayar S., Sherman L.A. Oscillating behavior of carbohydrate granule formation and dinitrogen fixation in the cyanobacterium Cyanothece sp. strain ATCC 51142. J Bacteriol. 1994;176:1586–1597. PubMed PMC

Bale N.J., Hopmans E.C., Zell C., Sobrinho R.L., Kim J.H., Sinninghe Damsté J.S. Long chain glycolipids with pentose head groups as biomarkers for marine endosymbiotic heterocystous cyanobacteria. Org Geochem. 2015;81:1–7.

Bale N.J., Villareal T.A., Hopmans E.C., Brussaard C.P.D., Besseling M., Dorhout D. C5 glycolipids of heterocystous cyanobacteria track symbiont abundance in the diatom Hemiaulus hauckii across the tropical North Atlantic. Biogeosciences. 2018;15:1229–1241.

Gómez F., Furuya K., Takeda S. Distribution of the cyanobacterium Richelia intracellularis as an epiphyte of the diatom Chaetoceros compressus in the western Pacific Ocean. J Plankton Res. 2005;27:323–330.

Nicolaisen K., Hahn A., Schleiff E. The cell wall in heterocyst formation by Anabaena sp. PCC 7120. J Basic Microbiol. 2009;49:5–24. PubMed

Foster R.A., Kuypers M.M.M., Vagner T., Paerl R.W., Musat N., Zehr J.P. Nitrogen fixation and transfer in open ocean diatom-cyanobacterial symbioses. ISME J. 2011;5:1484–1493. PubMed PMC

Venrick E.L. The distribution and significance of Richelia intracellularis Schmidt in the North Pacific Central Gyre. Limnol Oceanogr. 1974;19:437–445.

Mague T., Weare N., Holm-Hansen O. Nitrogen fixation in North Pacific Ocean. Mar Biol. 1974;24:109–119.

Knapp A.N. The sensitivity of marine N2 fixation to dissolved inorganic nitrogen. Front Microbiol. 2012;3:374. PubMed PMC

Knapp A.N., Dekaezemacker J., Bonnet S., Sohm J.A., Capone D.G. Sensitivity of Trichodesmium erythraeum and Crocosphaera watsonii abundance and N2 fixation rates to varying NO3− and PO43− concentrations in batch cultures. Aquat Microb Ecol. 2012;66:223–236.

Wang Z.C., Burns A., Watt G.D. Complex formation and O2 sensitivity of Azotobacter vinelandii nitrogenase and its component proteins. Biochemistry. 1985;24:214–221. PubMed

Holl C.M., Montoya J. Interactions between nitrate uptake and nitrogen fixation in continuous cultures of the marine diazotroph Trichodesmium (cyanobacteria) J Phycol. 2005;41:1178–1183.

Redfield A.C. The biological control of chemical factors in the environment. Am Sci. 1958;46:205–221. PubMed

Masuda T., Furuya K., Kodama T., Takeda S., Harrison P.J. Ammonium uptake and dinitrogen fixation by the unicellular nanocyanobacterium Crocosphaera watsonii in nitrogen-limited continuous cultures. Limnol Oceanogr. 2013;58:2029–2036.

Moore C.M., Mills M.M., Arrigo K.R., Berman-Frank I., Bopp L., Boyd P.W. Processes and patterns of oceanic nutrient limitation. Nat Geosci. 2013;6:701–710.

LaRoche J., Breitbarth E. Importance of the diazotrophs as a source of new nitrogen in the ocean. J Sea Res. 2005;53:67–91.

Mague T.H., Mague F.C., Holm-Hansen O. Physiology and chemical composition of nitrogen-fixing phytoplankton in the central North Pacific Ocean. Mar Biol. 1977;41:213–227.

Letelier R.M., Karl D.M. Trichodesmium spp. physiology and nutrietn fluxes in the North Pacific subtropical gyre. Aquat Microb Ecol. 1998;15:265–276.

Raven J.A. The iron and molybdenum use efficiencies of plant growth with different energy, carbon and nitrogen sources. New Phytol. 1988;109:279–287.

Ho T., Quigg A., Zoe V., Milligan A.J., Falkowski P.G., Morel F.M.M. The elemental composition of some marine phytoplankton. J Phycol. 2003;39:1145–1159.

Jacq V., Ridame C., L’Helguen S., Kaczmar F., Saliot A. Response of the unicellular diazotrophic cyanobacterium Crocosphaera watsonii to iron limitation. PLoS ONE. 2014;9 PubMed PMC

Cornejo-Castillo F.M., Zehr J.P. Hopanoid lipids may facilitate aerobic nitrogen fixation in the ocean. PNAS. 2019;116:18269–18271. PubMed PMC

Loescher C.R., Großkopf T., Desai F.D., Gill D., Schunck H., Croot P.L. Facets of diazotrophy in the oxygen minimum zone waters off Peru. ISME J. 2014;8:2180–2192. PubMed PMC

Mills M.M., Turk-Kubo K.A., van Dijken G.L., Henke B.A., Harding K., Wilson S.T. Unusual marine cyanobacteria/haptophyte symbiosis relies on N2 fixation even in N-rich environments. ISME J. 2020 PubMed PMC

Meyer J., Löscher C.R., Neulinger S.C., Reichel A.F., Loginova A., Borchard C. Changing nutrient stoichiometry affects phytoplankton production, DOP accumulation and dinitrogen fixation – A mesocosm experiment in the eastern tropical North Atlantic. Biogeosciences. 2016;13:781–794.

Dixon R., Kahn D. Genetic regulation of biological nitrogen fixation. Nat Rev Microbiol. 2004;2:621–631. PubMed

Farnelid H., Turk-Kubo K., Del Carmen Muñoz-Marín M, Zehr J.P. New insights into the ecology of the globally significant uncultured nitrogen-fixing symbiont UCYN-A. Aquat Microb Ecol. 2016;77:128–138.

Foster R.A., Zehr J.P. Diversity, genomics, and distribution of phytoplankton-cyanobacterium single-cell symbiotic associations. Annu Rev Microbiol. 2019;73:435–456. PubMed

Küpper H., Ferimazova N., Šetlík I., Berman-Frank I. Traffic lights in Trichodesmium. Regulation of photosynthesis for nitrogen fixation studied by chlorophyll fluorescence kinetic microscopy. Plant Physiol. 2004;135:2120–2133. PubMed PMC

Paerl H.W., Bebout B.M. Direct measurement of O2-depleted microzones in marine Oscillatoria: relation to N2 fixation. Science. 1988;241:442–445. PubMed

Eichner M.J., Klawonn I., Wilson S.T., Littmann S., Whitehouse M.J., Church M.J. Chemical microenvironments and single-cell carbon and nitrogen uptake in field-collected colonies of Trichodesmium under different pCO2. ISME J. 2017;11:1305–1317. PubMed PMC

Eichner M., Basu S., Wang S., de Beer D., Shaked Y. Mineral iron dissolution in Trichodesmium colonies: the role of O2 and pH microenvironments. Limnol Oceanogr. 2020;65:1149–1160.

Peters G.A., Mayne B.C. The Azolla, Anabaena azollae Relationship. Plant Physiol. 1974;53:820–824. PubMed PMC

Zehr J.P. How single cells work together. Science. 2015;349:2015–2017. PubMed

He C., Fong L.G., Young S.G., Jiang H. NanoSIMS imaging: an approach for visualizing and quantifying lipids in cells and tissues. J Investig Med. 2017;65:669–672. PubMed PMC

Hagino K, Onuma R, Kawachi M, Horiguchi T (2013) Discovery of an endosymbiotic nitrogen-fixing cyanobacterium UCYN-A in Braarudosphaera bigelowii (Prymnesiophyceae). PLoS ONE. 8: e81749. PubMed PMC

Thompson A.W., Foster R.A., Krupke A., Carter B.J., Musat N., Vaulot D. Unicellular cyanobacterium symbiotic with a single-celled eukaryotic alga. Science. 2019;337:1546–1550. PubMed

Shiozaki T., Fujiwara A., Ijichi M., Harada N., Nishino S., Nishi S. Diazotroph community structure and the role of nitrogen fixation in the nitrogen cycle in the Chukchi Sea (western Arctic Ocean) Limnol Oceanogr. 2018;63:2191–2205.

Harding K., Turk-Kubo K.A., Sipler R.E., Mills M.M., Bronk D.A., Zehr J.P. Symbiotic unicellular cyanobacteria fix nitrogen in the Arctic Ocean. PNAS. 2018;115:13371–13375. PubMed PMC

Montoya J.P., Holl C.M., Zehr J.P., Hansen A., Villareal T.A., Capone D.G. High rates of N2 fixation by unicellular diazotrophs in the oligotrophic Pacific Ocean. Nature. 2004;430:1027–1031. PubMed

Tripp H.J., Bench S.R., Turk K.A., Foster R.A., Desany B.A., Niazi F. Metabolic streamlining in an open-ocean nitrogen-fixing cyanobacterium. Nature. 2010;464:90–94. PubMed

Riemann L., Farnelid H., Steward G.F. Nitrogenase genes in non-cyanobacterial plankton: prevalence, diversity and regulation in marine waters. Aquat Microb Ecol. 2010;61:235–247.

Farnelid H., Andersson A.F., Bertilsson S., Al-soud W.A., Hansen L.H. Nitrogenase gene amplicons from global marine surface waters are dominated by genes of non-cyanobacteria. PLoS ONE. 2011;6 PubMed PMC

Farnelid H., Bentzon-Tilia M., Andersson A.F., Bertilsson S., Jost G., Labrenz M. Active nitrogen-fixing heterotrophic bacteria at and below the chemocline of the central Baltic Sea. ISME J. 2013;7:1413–1423. PubMed PMC

Nakayama T., Kamikawa R., Tanifuji G., Kashiyama Y., Ohkouchi N., Archibald J.M. Complete genome of a nonphotosynthetic cyanobacterium in a diatom reveals recent adaptations to an intracellular lifestyle. PNAS. 2014;111:11407–11412. PubMed PMC

Kumar P.K., Singh A., Ramesh R., Nallathambi T. N2 fixation in the Eastern Arabian Sea: probable role of heterotrophic diazotrophs. Front Mar Sci. 2017;4:1–10.

Farnelid H., Turk-Kubo K., Ploug H., Ossolinski J.E., Collins J.R., Van Mooy B.A.S. Diverse diazotrophs are present on sinking particles in the North Pacific Subtropical Gyre. ISME J. 2019;13:170–182. PubMed PMC

Paerl H.W., Prufert L.E. Oxygen-poor microzones as potential sites of microbial N2 fixation in nitrogen-depleted aerobic marine waters. Appl Environ Microbiol. 1987;53:1078–1087. PubMed PMC

Garcia HE, Locarnini RA, Boyer TP, Antonov JI, Baranova OK, Zweng MM, et al. (2013) World Ocean Atlas 2013, Volume 3: Dissolved Oxygen, Apparent Oxygen Utilization, and Oxygen Saturation. S.Levitus, ed.; A. Mishonov, Technical Ed. NOAA Atlas NESDIS. 3: 27.

Bianchi D., Weber T.S., Kiko R., Deutsch C. Global niche of marine anaerobic metabolisms expanded by particle microenvironments. Nat Geosci. 2018;11:1–6.

Bebout B.M., Paerl H.W., Crocker K.M., Prufert L.E. Diel interactions of oxygenic photosynthesis and N2 fixation (acetylene reduction) in a marine microbial mat community. Appl Environ Microbiol. 1987;53:2353–2362. PubMed PMC

Paerl H.W. Physiological ecology and regulation of N2 fixation in natural waters. Adv Microb Ecol. 1990;11:305–344.

Herbert R.A. Heterotrophic nitrogen fixation in shallow estuarine sediments. J Exp Mar Bio Ecol. 1975;18:215–225.

Daesch G., Mortenson L.E. Effect of ammonia on the synthesis and function of the N2-fixing enzyme system in Clostridium pasteurianum. J Bacteriol. 1972;110:103–109. PubMed PMC

Brooks R.H., Brexonik P.L., Putnam H.D., Keirn M.A. Nitrogen fixation in an estuarine environmenta: the Waccasassa on the Florida gulf coast. Limnol Oceanogr. 1971;16:701–710.

Kitano H. Systems biology: a brief overview. Science. 2002;295:1662–1664. PubMed

Kitano H. Computational systems biology. Nature. 2002;420:206–210. PubMed

Finzi-hart J.A., Pett-Ridge J., Weber P.K., Popa R., Fallon S.J., Gunderson T. Fixation and fate of C and N in the cyanobacterium Trichodesmium using nanometer-scale secondary ion mass spectrometry. PNAS. 2009;106:6345–6350. PubMed PMC

Foster R.A., Sztejrenszus S., Kuypers M.M.M. Measuring carbon and N2 fixation in field populations of colonial and free-living unicellular cyanobacteria using nanometer-scale secondary ion mass spectrometry. J Phycol. 2013;49:502–516. PubMed

Williams R.G., Follows M.J. Cambridge University Press; 2011. Ocean dynamics and the carbon cycle.

Holl C.M., Montoya J.P. Diazotrophic growth of the marine cyanobacterium Trichodesmium IMS101 in continuous culture: effects of growth rate on N2-fixation rate, biomass, and C:N: P stoichiometry. J Phycol. 2008;44:929–937. PubMed

Dron A., Rabouille S., Claquin P., Chang P., Raimbault V., Talec A. Light:dark (12:12 h) quantification of carbohydrate fluxes in Crocosphaera watsonii. Aquat Microb Ecol. 2012;68:43–55.

Rhee G.-Y., Lederman T.C. Effects of nitrogen sources on P-limited growth of Anabaena flos-aquae. J Phycol. 1983;185:179–185.

Rowell B.Y.P., Enticott S., Stewart W.D.P. Glutamine synthetase and nitrogenase activity in the blue-green alga Anabaena cylindrica. New Phytol. 1977;79:41–54.

Plunkett M.H., Knutson C.M., Barney B.M. Key factors affecting ammonium production by an Azotobacter vinelandii strain deregulated for biological nitrogen fixation. Microb Cell Fact. 2020;19:1–12. PubMed PMC

Luxem K.E., Kraepiel A.M.L., Zhang L., Waldbauer J.R., Zhang X. Carbon substrate re-orders relative growth of a bacterium using Mo-, V-, or Fe-nitrogenase for nitrogen fixation. Environ Microbiol. 2020;22:1397–1408. PubMed PMC

Gomez J.A., Höffner K., Barton P.I. Mathematical modeling of a raceway pond system for biofuels production. Comput Aided Chem Eng. 2016;38:2355–2360.

Sunagawa S., Coelho L.P., Chaffron S., Kultima J.R., Labadie K., Salazar G. Structure and function of the global ocean microbiome. Science. 2015;348:1–10. PubMed

Saito M.A., Bertrand E.M., Duffy M.E., Gaylord D.A., Held N.A., Hervey W.J. Progress and challenges in ocean metaproteomics and proposed best practices for data sharing. J Proteome Res. 2019;18:1461–1476. PubMed PMC

Gilbert J.A., Field D., Huang Y., Edwards R., Li W., Gilna P. Detection of large numbers of novel sequences in the metatranscriptomes of complex marine microbial communities. PLoS ONE. 2008;3 PubMed PMC

Daniel R. The metagenomics of soil. Nat Rev Microbiol. 2005;3:470–478. PubMed

Keiblinger K.M., Wilhartitz I.C., Schneider T., Roschitzki B., Schmid E., Eberl L. Soil metaproteomics – Comparative evaluation of protein extraction protocols. Soil Biol Biochem. 2012;54:14–24. PubMed PMC

Carvalhais L.C., Dennis P.G., Tyson G.W., Schenk P.M. Application of metatranscriptomics to soil environments. J Microbiol Methods. 2012;91:246–251. PubMed

Horgan R.P., Kenny L.C. ‘Omic’ technologies: genomics, transcriptomics, proteomics and metabolomics. Obstet Gynaecol. 2011;13:189–195.

Wilson S.T., Aylward F.O., Ribalet F., Barone B., Casey J.R., Connell P.E. Coordinated regulation of growth, activity and transcription in natural populations of the unicellular nitrogen-fixing cyanobacterium Crocosphaera. Nat Microbiol. 2017;2 PubMed

Biegala I.C., Raimbault P. High abundance of diazotrophic picocyanobacteria (<3 μm) in a Southwest Pacific coral lagoon. Aquat Microb Ecol. 2008;51:45–53.

Luo Y.W., Doney S.C., Anderson L.A., Benavides M., Berman-Frank I., Bode A. Database of diazotrophs in global ocean: abundance, biomass and nitrogen fixation rates. Earth Syst Sci Data. 2012;4:47–73.

Cassar N., Tang W., Gabathuler H., Huang K. Method for high frequency underway N2 fixation measurements: flow-through incubation acetylene reduction assays by cavity ring down laser absorption Spectroscopy (FARACAS) Anal Chem. 2018;90:2839–2851. PubMed

Kempes C.P., Wang L., Amend J.P., Doyle J., Hoehler T. Evolutionary tradeoffs in cellular composition across diverse bacteria. ISME J. 2016;10:2145–2157. PubMed PMC

Menden-deuer S., Lessard E.J. Carbon to volume relationships for dinoflagellates, diatoms, and other protist plankton. Limnol Oceanogr. 2000;45:569–579.

Strathmann R.R. Estimating the organic carbon content of phytoplankton from cell volume or plasma volume. Limnol Oceanogr. 1967;12:411–418.

Hutchins D.A., Fu F.X., Zhang Y., Warner M.E., Feng Y., Portune K. CO2 control of Trichodesmium N2 fixation, photosynthesis, growth rates, and elemental ratios: implications for past, present, and future ocean biogeochemistry. Limnol Oceanogr. 2007;52:1293–1304.

Fernandez A.C., Phillies G.D.J. Temperature dependence of the diffusion coefficient of polystyrene latex spheres. Biopolymers. 1983;22:593–595.

Broecker W.S., Peng T.-H. Gas exchange rates between air and sea. Tellus. 1974;26:21–35.

Dechatiwongse P., Srisamai S., Maitland G., Hellgardt K. Effects of light and temperature on the photoautotrophic growth and photoinhibition of nitrogen-fixing cyanobacterium Cyanothece sp. ATCC 51142. Algal Res. 2014;5:103–111.

Fu F.X., Yu E., Garcia N.S., Gale J., Luo Y., Webb E.A. Differing responses of marine N2 fixers to warming and consequences for future diazotroph community structure. Aquat Microb Ecol. 2014;72:33–46.

Michiels J., Verreth C., Vanderleyden J. Effects of temperature stress on bean-nodulating Rhizobium strains. Appl Environ Microbiol. 1994;60:1206–1212. PubMed PMC

Kuhla J., Oelze J. Dependence of nitrogenase switch-off upon oxygen stress on the nitrogenase activity in Azotobacter vinelandii. J Bacteriol. 1988;170:5325–5329. PubMed PMC

Pirt S.J. Maintenance Energy: a general model for energy-limited and energy-sufficient growth. Arch Microbiol. 1982;133:300–302. PubMed

Elrifi I.R., Turpin D.H. Steady-state luxury consumption and the concept of optimum nutrient ratios: a study with phosphate and nitrate limited Selenastrum minutum (Chlorophyta) J Phycol. 1985;21:592–602.

Rhee G.-Y. Effects of N: P atomic ratios and nitrate limitation on algal growth, cell compostion, and nitrate uptake. Limnol Oceanogr. 1978;23:10–25.

Foster R.A., Goebel N.L., Zehr J.P. Isolation of Calothrix rhizosoleniae (cyanobacteria) strain SC01 from Chaetoceros (bacillariophyta) spp. diatoms of the subtropical North Pacific Ocean. J Phycol. 2010;46:1028–1037.

Compaoré J., Stal L.J. Effect of temperature on the sensitivity of nitrogenase to oxygen in two heterocystous cyanobacteria. J Phycol. 2010;3:1172–1179.

Masuda T., Bernát G., Bečková M., Kotabová E., Lawrenz E., Lukeš M. Diel regulation of photosynthetic activity in the oceanic unicellular diazotrophic cyanobacterium Crocosphaera watsonii WH8501. Environ Microbiol. 2018;20:546–560. PubMed

Sakshaug E., Andresen K., Myklestad S., Olsen Y. Nutrient status of phytoplankton communities in Norwegian waters (marine, brackish, and fresh) as revealed by their chemical composition. J Plankt Researc. 1983;5:175–196.

Laws E.A., Bannister T.T. Nutrient- and light-limited growth of Thalassiosira fluviatilis in continuous culture, with implications for phytoplankton growth in the ocean. Limnol Oceanogr. 1980;25:457–473.

Dettmer Aronov PA, Hammock B.D. Mass spectrometry-based metabolomics. Mass Spectrom Rev. 2007;26:51–78. PubMed PMC

Johnson C.H., Ivanisevic J., Siuzdak G. Metabolomics: beyond biomarkers and towards mechanisms. Nat Rev Mol Cell Biol. 2016;17:451–459. PubMed PMC

Quigg A., Beardall J. Protein turnover in relation to maintenance metabolism at low photon flux in two marine microalgae. Plant Cell Environ. 2003;26:693–703.

Gu H., Du J., Carnevale Neto F., Carroll P.A., Turner S.J., Chiorean E.G. Metabolomics method to comprehensively analyze amino acids in different domains. Analyst. 2015;140:2726–2734. PubMed PMC

Crocosphaera as a Major Consumer of Fixed Nitrogen

Quantifying Cyanothece growth under DIC limitation