The photoautotrophic, unicellular N2-fixer, Cyanothece, is a model organism that has been widely used to study photosynthesis regulation, the structure of photosystems, and the temporal segregation of carbon (C) and nitrogen (N) fixation in light and dark phases of the diel cycle. Here, we present a simple quantitative model and experimental data that together, suggest external dissolved inorganic carbon (DIC) concentration as a major limiting factor for Cyanothece growth, due to its high C-storage requirement. Using experimental data from a parallel laboratory study as a basis, we show that after the onset of the light period, DIC was rapidly consumed by photosynthesis, leading to a sharp drop in the rate of photosynthesis and C accumulation. In N2-fixing cultures, high rates of photosynthesis in the morning enabled rapid conversion of DIC to intracellular C storage, hastening DIC consumption to levels that limited further uptake. The N2-fixing condition allows only a small fraction of fixed C for cellular growth since a large fraction was reserved in storage to fuel night-time N2 fixation. Our model provides a framework for resolving DIC limitation in aquatic ecosystem simulations, where DIC as a growth-limiting factor has rarely been considered, and importantly emphasizes the effect of intracellular C allocation on growth rate that varies depending on the growth environment.

Balaton Limnological Research Institute Eötvös Loránd Research Network Tihany Hungary

Department Experimental Limnology Leibniz Institute of Freshwater Ecology and Inland Fisheries Stechlin Germany

Department of Adaptive Biotechnologies Global Change Research Institute Czech Academy of Sciences Brno Czech Republic

Graduate School of Oceanography University of Rhode Island Narragansett Rhode Island USA

Institute of Microbiology The Czech Academy of Sciences Třeboň Czech Republic

Laboratoire de Biologie des ORganismes et Ecosystèmes Aquatiques UMR 8067 Muséum National d'Histoire Naturelle CNRS IRD Sorbonne Université Université de Caen Normandie Normandie Université Esplanade de la Paix F 14032 Caen France

Laboratory of Electron Microscopy Institute of Parasitology Biology Centre of the Czech Academy of Sciences and Faculty of Science University of South Bohemia České Budějovice Czech Republic

School of Oceanography University of Washington Seattle WA USA

Sorbonne Université CNRS Laboratoire d'Océanographie Microbienne LOMIC F 66650 Banyuls sur mer France

University of Technology Sydney Climate Change Cluster Faculty of Science Ultimo NSW 2007 Australia

Erratum v

Comput Struct Biotechnol J. 2022 Jan 01;20:385. doi: 10.1016/j.csbj.2021.12.037. PubMed

Zobrazit více v PubMed

Field C.B., Behrenfeld M.J., Randerson J.T., Falkowski P. Primary production of the biosphere: Integrating terrestrial and oceanic components. Science. 1998;281(5374):237–240. PubMed

Zehr J.P., Waterbury J.B., Turner P.J., Montoya J.P., Omoregie E., Steward G.F., et al. Unicellular cyanobacteria fix N2 in the subtropical North Pacific Ocean. Nature. 2001;412(6847):635–638. PubMed

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(7003):1027–1031. PubMed

Moisander P.H., Beinart R.A., Hewson I., White A.E., Johnson K.S., Carlson C.A., et al. Unicellular cyanobacterial distributions broaden the oceanic N2 fixation domain. Science. 2010;327(5972):1512–1514. PubMed

Gruber N., Galloway J.N. An Earth-system perspective of the global nitrogen cycle. Nature. 2008;451(7176):293–296. PubMed

Inomura K., Deutsch C., Masuda T., Prášil O., Follows M.J. Quantitative models of nitrogen-fixing organisms. Comput Struct Biotechnol J. 2020;18:3905–3924. PubMed PMC

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(5):1284–1292. PubMed PMC

Meunier P.C., Colón-lópez M.S., Sherman L.A. Temporal changes in state transitions and photosystem organization in the unicellular, diazotrophic cyanobacterium Cyanothece sp. ATCC 5112. Plant Physiol. 1997;115:991–1000. PubMed PMC

Rabouille S., Van de Waal D.B., Matthijs H.C.P., Huisman J. Nitrogen fixation and respiratory electron transport in the cyanobacterium Cyanothece under different light/dark cycles. FEMS Microbiol Ecol. 2014;87(3):630–638. PubMed

Rabouille S., Campbell D.A., Masuda T., Zavřel T., Bernat G., Polerecky L., et al. Electron and biomass dynamics of Cyanothece under interacting nitrogen and carbon limitations. Front Microbiol. 2021;12 PubMed PMC

Gallon J.R. Tansley Review No. 44 Reconciling the incompatible: N2 fixation and O2. New Phytol. 1992;122(4):571–609.

Rabouille S., Claquin P. Photosystem-II shutdown evolved with nitrogen fixation in the unicellular diazotroph Crocosphaera watsonii. Environ Microbiol. 2016;18(2):477–485. PubMed

Masuda T., Bernát G., Bečková M., Kotabová E., Lawrenz E., Lukeš M., et al. Diel regulation of photosynthetic activity in the oceanic unicellular diazotrophic cyanobacterium Crocosphaera watsonii WH8501. Environ Microbiol. 2018;20(2):546–560. PubMed

Dron A., Rabouille S., Claquin P., Talec A., Raimbault V., Sciandra A. Photoperiod length paces the temporal orchestration of cell cycle and carbon-nitrogen metabolism in Crocosphaera watsonii. Environ Microbiol. 2013;15:3292–3304. PubMed

Moore C.M., Mills M.M., Arrigo K.R., Berman-Frank I., Bopp L., Boyd P.W., et al. Processes and patterns of oceanic nutrient limitation. Nat Geosci. 2013;6(9):701–710.

Huertas M., López-Maury L., Giner-Lamia J., Sánchez-Riego A., Florencio F. Metals in cyanobacteria: Analysis of the copper, nickel, cobalt and arsenic homeostasis mechanisms. Life. 2014;4(4):865–886. PubMed PMC

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.

Riebesell U., Wolf-Gladrow D.A., Smetacek V. Carbon dioxide limitation of marine phytoplankton growth rates. Nature. 1993;361(6409):249–251.

Gattuso J.P., Magnan A., Billé R., Cheung W.W.L., Howes E.L., Joos F., et al. Contrasting futures for ocean and society from different anthropogenic CO2 emissions scenarios. Science. 2015;349:aac4722. PubMed

Yang Y., Hansson L., Gattuso J.-P. Data compilation on the biological response to ocean acidification: An update. Earth Syst Sci Data. 2016;8(1):79–87.

Gao K., Beardall J., Häder D.P., Hall-Spencer J.M., Gao G., Hutchins D.A. Effects of ocean acidification on marine photosynthetic organisms under the concurrent influences of warming, UV radiation, and deoxygenation. Front Mar Sci. 2019;6:1–18.

Eichner M., Rost B., Kranz S.A. Diversity of ocean acidification effects on marine N2 fixers. J Exp Mar Biol Ecol. 2014;457:199–207.

Evans W., Hales B., Strutton P.G. Seasonal cycle of surface ocean pCO2 on the Oregon shelf. J Geophys Res Oceans. 2011;116:C05012.

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

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 PubMed PMC

Inomura K., Bragg J., Riemann L., Follows M.J., Virolle M.-J. A quantitative model of nitrogen fixation in the presence of ammonium. PLoS One. 2018;13(11):e0208282. PubMed PMC

Inomura K., Wilson S.T., Deutsch C., Gilbert J. Mechanistic model for the coexistence of nitrogen fixation and photosynthesis in marine Trichodesmium. mSystems. 2019;4(4) doi: 10.1128/mSystems.00210-19. PubMed DOI 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(2):192. doi: 10.3390/plants9020192. PubMed DOI PMC

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(1):166–175. PubMed PMC

Inomura K., Deutsch C., Wilson S.T., Masuda T., Lawrenz E., Bučinská L., et al. Quantifying oxygen management and temperature and light dependencies of nitrogen fixation by Crocosphaera watsonii. mSphere. 2019;4(6) doi: 10.1128/mSphere.00531-19. PubMed DOI 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(5):3217–3227. PubMed PMC

Agawin N.S.R., Rabouille S., Veldhuis M.J.W., Servatius L., Hol S., van Overzee H.M.J., et al. Competition and facilitation between unicellular nitrogen-fixing cyanobacteria and non-nitrogen-fixing phytoplankton species. Limnol Oceanogr. 2007;52(5):2233–2248.

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 Model. 2014;291:121–133.

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

Deschamps P., Colleoni C., Nakamura Y., Suzuki E., Putaux J.-L., Buleon A., et al. Metabolic symbiosis and the birth of the plant kingdom. Mol Biol Evol. 2008;25(3):536–548. PubMed

Rittmann B.E., McCarty P.L. McGraw-Hill; New York, NY: 2001. Environmental Biotechnology: Principles and Applications.

Ji X., Verspagen J.M.H., van de Waal D.B., Rost B., Huisman J. Phenotypic plasticity of carbon fixation stimulates cyanobacterial blooms at elevated CO2. Sci Adv. 2020;6:eaax2926. PubMed PMC

Polerecky L., Masuda T., Eichner M., Rabouille S., Vancová M., Kienhuis M.V.M., et al. Temporal patterns and intra- and inter-cellular variability in carbon and nitrogen assimilation by the unicellular cyanobacterium Cyanothece sp. ATCC 51142. Front Microbiol. 2021;12:620915. PubMed PMC

Swinnen I.A.M., Bernaerts K., Dens E.J.J., Geeraerd A.H., Van Impe J.F. Predictive modelling of the microbial lag phase: A review. Int J Food Microbiol. 2004;94:137–159. PubMed

Mulderij G., Mooij W.M., Smolders A.J.P., Donk E.V. Allelopathic inhibition of phytoplankton by exudates from Stratiotes aloides. Aquat Bot. 2005;82(4):284–296.

Rolfe M.D., Rice C.J., Lucchini S., Pin C., Thompson A., Cameron A.D.S., et al. Lag phase is a distinct growth phase that prepares bacteria for exponential growth and involves transient metal accumulation. J Bacteriol. 2012;194(3):686–701. PubMed PMC

Miller A.G., Colman B. Active transport and accumulation of bicarbonate by a unicellular cyanobacterium. J Bacteriol. 1980;143(3):1253–1259. PubMed PMC

Miller A.G., Espie G.S., Canvin D.T. Physiological aspects of CO2 and HCO3− transport by cyanobacteria: a review. Can J Bot. 1990;68(6):1291–1302.

Kaplan A., Badger M.R., Berry J.A. Photosynthesis and the intracellular inorganic carbon pool in the bluegreen alga Anabaena variabilis: Response to external CO2 concentration. Planta. 1980;149(3):219–226. PubMed

Badger MR, Spalding MH (2000) CO2 acquisition, concentration and fixation in cyanobacteria and algae. In: Leegood RC, Sharkey TD and von Caemmerer S (eds), Advances in Photosynthesis, Vol 9. Photosynthesis: Physiology and Metabolism. 9: 399–434.

Price G.D., Badger M.R., Woodger F.J., Long B.M. Advances in understanding the cyanobacterial CO2-concentrating-mechanism (CCM): Functional components, Ci transporters, diversity, genetic regulation and prospects for engineering into plants. J Exp Bot. 2008;59:1441–1461. PubMed

Ogawa T., Kaplan A. Inorganic carbon acquisition systems in cyanobacteria. Photosynth Res. 2003;77:105–115. PubMed

Eichner M., Thoms S., Kranz S.A., Rost B. Cellular inorganic carbon fluxes in Trichodesmium: A combined approach using measurements and modelling. J Exp Bot. 2015;66:749–759. PubMed PMC

Ploug H., Adam B., Musat N., Kalvelage T., Lavik G., Wolf-Gladrow D., et al. Carbon, nitrogen and O2 fluxes associated with the cyanobacterium Nodularia spumigena in the Baltic Sea. ISME J. 2011;5:1549–1558. PubMed PMC

Zavřel T., Očenášová P., Sinetova M., Červený J. Determination of Storage (Starch/Glycogen) and Total Saccharides Content in Algae and Cyanobacteria by a Phenol-Sulfuric Acid Method. Bio-Protocol. 2018;8:1–13. PubMed PMC

The balance between photosynthesis and respiration explains the niche differentiation between Crocosphaera and Cyanothece