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Efficient carbon and nitrogen transfer from marine diatom aggregates to colonizing bacterial groups

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  • Smith, D. C., Simon, M., Alldredge, A. L. & Azam, F. Intense hydrolytic enzyme activity on marine aggregates and implications for rapid particle dissolution. Nature 359, 139–142. https://doi.org/10.1038/359139a0 (1992).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Alldredge, A. L. & Gotschalk, C. C. Direct observations of the mass flocculation of diatom blooms: Characteristics, settling velocities and formation of diatom aggregates. Deep Sea Res. A 36, 159–171. https://doi.org/10.1016/0198-0149(89)90131-3 (1989).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Jackson, G. A. A model of the formation of marine algal flocs by physical coagulation processes. Deep Sea Res. A 37, 1197–1211. https://doi.org/10.1016/0198-0149(90)90038-w (1990).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Kiørboe, T., Lundsgaard, C., Olesen, M. & Hansen, J. L. S. Aggregation and sedimentation processes during a spring phytoplankton bloom: A field experiment to test coagulation theory. J. Mar. Res. 52, 297–323. https://doi.org/10.1357/0022240943077145 (1994).

    Article 

    Google Scholar
     

  • Jackson, G. Coagulation Theory and Models of Oceanic Plankton Aggregation (CRC Press, 2005).


    Google Scholar
     

  • Grossart, H. P., Kiorboe, T., Tang, K. & Ploug, H. Bacterial colonization of particles: Growth and interactions. Appl. Environ. Microb. 69, 3500–3509. https://doi.org/10.1128/aem.69.6.3500-3509.2003 (2003).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Kiorboe, T., Tang, K., Grossart, H. P. & Ploug, H. Dynamics of microbial communities on marine snow aggregates: Colonization, growth, detachment, and grazing mortality of attached bacteria. Appl. Environ. Microbiol. 69, 3036–3047. https://doi.org/10.1128/AEM.69.6.3036 (2003).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Martin, J. H., Knauer, G. A., Karl, D. M. & Broenkow, W. W. VERTEX: Carbon cycling in the northeast pacific. Deep Sea Res. A 34, 267–285. https://doi.org/10.1016/0198-0149(87)90086-0 (1987).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Buesseler, K. O. et al. VERTIGO (vertical transport in the global ocean): A study of particle sources and flux attenuation in the North Pacific. Deep Sea Res. II 55, 1522–1539. https://doi.org/10.1016/j.dsr2.2008.04.024 (2008).

    ADS 
    Article 

    Google Scholar
     

  • Grossart, H. P., Tang, K. W., Kiorboe, T. & Ploug, H. Comparison of cell-specific activity between free-living and attached bacteria using isolates and natural assemblages. FEMS Microbiol. Lett. 266, 194–200. https://doi.org/10.1111/j.1574-6968.2006.00520.x (2007).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Martinez, J., Smith, D. C., Steward, G. F. & Azam, F. Variability in ectohydrolytic enzyme activities of pelagic marine bacteria and its significance for substrate processing in the sea. Aquat. Microb. Ecol. 10, 223–230. https://doi.org/10.3354/ame010223 (1996).

    Article 

    Google Scholar
     

  • Kellogg, C. T. E. et al. Evidence for microbial attenuation of particle flux in the Amundsen Gulf and Beaufort Sea: Elevated hydrolytic enzyme activity on sinking aggregates. Polar Biol. 34, 2007–2023. https://doi.org/10.1007/s00300-011-1015-0 (2011).

    Article 

    Google Scholar
     

  • Jiao, N. et al. Microbial production of recalcitrant dissolved organic matter: Long-term carbon storage in the global ocean. Nat. Rev. Microbiol. 8, 593–599. https://doi.org/10.1038/nrmicro2386 (2010).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Jiao, N. & Zheng, Q. The microbial carbon pump: From genes to ecosystems. Appl. Environ. Microbiol. 77, 7439–7444. https://doi.org/10.1128/AEM.05640-11 (2011).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Buchan, A., LeCleir, G. R., Gulvik, C. A. & Gonzalez, J. M. Master recyclers: Features and functions of bacteria associated with phytoplankton blooms. Nat. Rev. Microbiol. 12, 686–698. https://doi.org/10.1038/nrmicro3326 (2014).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Smriga, S., Fernandez, V. I., Mitchell, J. G. & Stocker, R. Chemotaxis toward phytoplankton drives organic matter partitioning among marine bacteria. Proc. Natl. Acad. Sci. USA 113, 1576–1581. https://doi.org/10.1073/pnas.1512307113 (2016).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Secchi, E. et al. The effect of flow on swimming bacteria controls the initial colonization of curved surfaces. Nat. Commun. 11, 2851. https://doi.org/10.1038/s41467-020-16620-y (2020).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Acinas, S. G., Antón, J. & Rodríguez-Valera, F. Diversity of free-living and attached bacteria in offshore Western Mediterranean Waters as depicted by analysis of genes encoding 16S rRNA. Appl. Environ. Microb. 65, 514–522 (1999).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Grossart, H. P., Levold, F., Allgaier, M., Simon, M. & Brinkhoff, T. Marine diatom species harbour distinct bacterial communities. Environ. Microbiol. 7, 860–873. https://doi.org/10.1111/j.1462-2920.2005.00759.x (2005).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Mestre, M. et al. Sinking particles promote vertical connectivity in the ocean microbiome. Proc. Natl. Acad. Sci. USA 115, E6799–E6807. https://doi.org/10.1073/pnas.1802470115 (2018).

    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Rieck, A., Herlemann, D. P., Jurgens, K. & Grossart, H. P. Particle-associated differ from free-living bacteria in surface waters of the Baltic Sea. Front. Microbiol. 6, 1297. https://doi.org/10.3389/fmicb.2015.01297 (2015).

    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Ziervogel, K., Steen, A. D. & Arnosti, C. Changes in the spectrum and rates of extracellular enzyme activities in seawater following aggregate formation. Biogeosciences 7, 1007–1015. https://doi.org/10.5194/bg-7-1007-2010 (2010).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Stocker, R., Seymour, J. R., Samadani, A., Hunt, D. E. & Polz, M. F. Rapid chemotactic response enables marine bacteria to exploit ephemeral microscale nutrient patches. Proc. Natl. Acad. Sci. USA 105, 4209–4214. https://doi.org/10.1073/pnas.0709765105 (2008).

    ADS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Lopez-Perez, M. et al. Genomes of surface isolates of Alteromonas macleodii: The life of a widespread marine opportunistic copiotroph. Sci. Rep. 2, 696. https://doi.org/10.1038/srep00696 (2012).

    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Thiele, S., Fuchs, B. M., Amann, R. & Iversen, M. H. Colonization in the photic zone and subsequent changes during sinking determine bacterial community composition in marine snow. Appl. Environ. Microbiol. 81, 1463–1471. https://doi.org/10.1128/AEM.02570-14 (2015).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Bachmann, J. et al. Environmental drivers of free-living vs particle-attached bacterial community composition in the mauritania upwelling system. Front. Microbiol. 9, 2836. https://doi.org/10.3389/fmicb.2018.02836 (2018).

    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Kirchman, D. The ecology of Cytophaga-Flavobacteria in aquatic environments. FEMS Microbiol. Ecol. 39, 91–100. https://doi.org/10.1016/s0168-6496(01)00206-9 (2002).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Bizic-Ionescu, M. et al. Comparison of bacterial communities on limnic versus coastal marine particles reveals profound differences in colonization. Environ. Microbiol. 17, 3500–3514. https://doi.org/10.1111/1462-2920.12466 (2015).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Zhao, Z., Baltar, F. & Herndl, G. J. Linking extracellular enzymes to phylogeny indicates a predominantly particle-associated lifestyle of deep-sea prokaryotes. Sci. Adv. 6, 4354. https://doi.org/10.1126/sciadv.aaz4354 (2020).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Baumas, C. M. J. et al. Mesopelagic microbial carbon production correlates with diversity across different marine particle fractions. ISME J. 15, 1695–1708. https://doi.org/10.1038/s41396-020-00880-z (2021).

    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Ploug, H., Grossart, H. P., Azam, F. & Jørgensen, B. B. Photosynthesis, respiration, and carbon turnover in sinking marine snow from surface waters of Southern California Bight: Implications for the carbon cycle in the ocean. Mar. Ecol. Prog. Ser. 179, 1–11. https://doi.org/10.3354/meps179001 (1999).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Ploug, H. & Grossart, H.-P. Bacterial growth and grazing on diatom aggregates: Respiratory carbon turnover as a function of aggregate size and sinking velocity. Limnol. Oceanogr. 45, 1467–1475. https://doi.org/10.4319/lo.2000.45.7.1467 (2000).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Ebrahimi, A., Schwartzman, J. & Cordero, O. X. Cooperation and spatial self-organization determine rate and efficiency of particulate organic matter degradation in marine bacteria. Proc. Natl. Acad. Sci. USA 116, 23309–23316. https://doi.org/10.1073/pnas.1908512116 (2019).

    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Grossart, H.-P. & Ploug, H. Microbial degradation of organic carbon and nitrogen on diatom aggregates. Limnol. Oceanogr. 46, 267–277. https://doi.org/10.4319/lo.2001.46.2.0267 (2001).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Datta, M. S., Sliwerska, E., Gore, J., Polz, M. F. & Cordero, O. X. Microbial interactions lead to rapid micro-scale successions on model marine particles. Nat. Commun. 7, 11965. https://doi.org/10.1038/ncomms11965 (2016).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Kiorboe, T., Grossart, H. P., Ploug, H. & Tang, K. Mechanisms and rates of bacterial colonization of sinking aggregates. Appl. Environ. Microbiol. 68, 3996–4006. https://doi.org/10.1128/AEM.68.8.3996-4006.2002 (2002).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Vaqué, D., Duarte, C. M. & Marrasé, C. Influence of algal population dynamics on phytoplankton colonization by bacteria: Evidence from two diatom species. Mar. Ecol. Prog. Ser. 65, 201–203. https://doi.org/10.3354/meps065201 (1990).

    ADS 
    Article 

    Google Scholar
     

  • Grossart, H.-P. & Ploug, H. Bacterial production and growth efficiencies: Direct measurements on riverine aggregates. Limnol. Oceanogr. 45, 436–445. https://doi.org/10.4319/lo.2000.45.2.0436 (2000).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Duhamel, S. et al. Growth and specific P-uptake rates of bacterial and phytoplanktonic communities in the Southeast Pacific (BIOSOPE cruise). Biogeosciences 4, 941–956. https://doi.org/10.5194/bg-4-941-2007 (2007).

    ADS 
    Article 

    Google Scholar
     

  • Kirchman, D. L. Growth rates of microbes in the oceans. Annu. Rev. Mar. Sci. 8, 285–309. https://doi.org/10.1146/annurev-marine-122414-033938 (2016).

    ADS 
    Article 

    Google Scholar
     

  • Brumley, D. R. et al. Cutting through the noise: Bacterial chemotaxis in marine microenvironments. Front. Mar. Sci. 7, 527. https://doi.org/10.3389/fmars.2020.00527 (2020).

    Article 

    Google Scholar
     

  • Thomas, T. et al. Analysis of the Pseudoalteromonas tunicata genome reveals properties of a surface-associated life style in the marine environment. PLoS ONE 3, e3252. https://doi.org/10.1371/journal.pone.0003252 (2008).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Varbanets, L. D. et al. The black sea bacteria-producers of hydrolytic enzymes. Mikrobiol. Z. 73, 9–15 (2011).

    CAS 
    PubMed 

    Google Scholar
     

  • Sapp, M. et al. Species-specific bacterial communities in the phycosphere of microalgae?. Microb. Ecol. 53, 683–699. https://doi.org/10.1007/s00248-006-9162-5 (2007).

    Article 
    PubMed 

    Google Scholar
     

  • Sarmento, H. & Gasol, J. M. Use of phytoplankton-derived dissolved organic carbon by different types of bacterioplankton. Environ. Microbiol. 14, 2348–2360. https://doi.org/10.1111/j.1462-2920.2012.02787.x (2012).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Gram, L., Grossart, H. P., Schlingloff, A. & Kiorboe, T. Possible quorum sensing in marine snow bacteria: Production of acylated homoserine lactones by Roseobacter strains isolated from marine snow. Appl. Environ. Microbiol. 68, 4111–4116. https://doi.org/10.1128/AEM.68.8.4111 (2002).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Arandia-Gorostidi, N. et al. Warming the phycosphere: Differential effect of temperature on the use of diatom-derived carbon by two copiotrophic bacterial taxa. Environ. Microbiol. 22, 1381–1396. https://doi.org/10.1111/1462-2920.14954 (2020).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Sarmento, H., Morana, C. & Gasol, J. M. Bacterioplankton niche partitioning in the use of phytoplankton-derived dissolved organic carbon: Quantity is more important than quality. ISME J 10, 2582–2592. https://doi.org/10.1038/ismej.2016.66 (2016).

    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Grossart, H. P. & Simon, M. Bacterial colonization and microbial decomposition of limnetic organic aggregates (lake snow). Aquat. Microb. Ecol. 15, 127–140. https://doi.org/10.3354/ame015127 (1998).

    Article 

    Google Scholar
     

  • Kiørboe, T. & Jackson, G. A. Marine snow, organic solute plumes, and optimal chemosensory behavior of bacteria. Limnol. Oceanogr. 46, 1309–1318. https://doi.org/10.4319/lo.2001.46.6.1309 (2001).

    ADS 
    Article 

    Google Scholar
     

  • Chakraborty, S. et al. Quantifying nitrogen fixation by heterotrophic bacteria in sinking marine particles. Nat. Commun. 12, 4085. https://doi.org/10.1038/s41467-021-23875-6 (2021).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Hygum, B. H., Petersen, J. W. & Søndergaard, M. Dissolved organic carbon released by zooplankton grazing activity-a high-quality substrate pool for bacteria. J. Plankton Res. 19, 97–111. https://doi.org/10.1093/plankt/19.1.97 (1997).

    CAS 
    Article 

    Google Scholar
     

  • Suttle, C. A. Marine viruses–major players in the global ecosystem. Nat. Rev. Microbiol. 5, 801–812. https://doi.org/10.1038/nrmicro1750 (2007).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Bizic-Ionescu, M., Ionescu, D. & Grossart, H. P. Organic particles: Heterogeneous hubs for microbial interactions in aquatic ecosystems. Front. Microbiol. 9, 2569. https://doi.org/10.3389/fmicb.2018.02569 (2018).

    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Arandia-Gorostidi, N., Weber, P. K., Alonso-Saez, L., Moran, X. A. & Mayali, X. Elevated temperature increases carbon and nitrogen fluxes between phytoplankton and heterotrophic bacteria through physical attachment. ISME J. 11, 641–650. https://doi.org/10.1038/ismej.2016.156 (2017).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Worrich, A. et al. Mycelium-mediated transfer of water and nutrients stimulates bacterial activity in dry and oligotrophic environments. Nat. Commun. 8(1), 15472. https://doi.org/10.1038/ncomms15472 (2017).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Iversen, M. H. & Ploug, H. Ballast minerals and the sinking carbon flux in the ocean: Carbon-specific respiration rates and sinking velocity of marine snow aggregates. Biogeosciences 7, 2613–2624. https://doi.org/10.5194/bg-7-2613-2010 (2010).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Baltar, F., Arístegui, J., Gasol, J. M., Sintes, E. & Herndl, G. J. Evidence of prokaryotic metabolism on suspended particulate organic matter in the dark waters of the subtropical North Atlantic. Limnol. Oceanogr. 54, 182–193. https://doi.org/10.4319/lo.2009.54.1.0182 (2009).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Schneider, B., Schlitzer, R., Fischer, G. & Nöthig, E.-M. Depth-dependent elemental compositions of particulate organic matter (POM) in the ocean. Glob. Biogeochem. Cycles https://doi.org/10.1029/2002gb001871 (2003).

    Article 

    Google Scholar
     

  • Jannasch, H. W. & Wirsen, C. O. Microbial activities in undecompressed and decompressed deep-seawater samples. Appl. Environ. Microbiol. 43, 1116–1124. https://doi.org/10.1128/AEM.43.5.1116-1124.1982 (1982).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Tamburini, C., Garcin, J., Ragot, M. & Bianchi, A. Biopolymer hydrolysis and bacterial production under ambient hydrostatic pressure through a 2000m water column in the NW Mediterranean. Deep Sea Res. II(49), 2109–2123. https://doi.org/10.1016/s0967-0645(02)00030-9 (2002).

    ADS 
    Article 

    Google Scholar
     

  • Iversen, M. H. & Ploug, H. Temperature effects on carbon-specific respiration rate and sinking velocity of diatom aggregates: Potential implications for deep ocean export processes. Biogeosciences 10, 4073–4085. https://doi.org/10.5194/bg-10-4073-2013 (2013).

    ADS 
    Article 

    Google Scholar
     

  • Guillard, R. R. & Ryther, J. H. Studies of marine planktonic diatoms I Cyclotella nana Hustedt, and Detonula confervacea (cleve) Gran. Can. J. Microbiol. 8, 229–239. https://doi.org/10.1139/m62-029 (1962).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Pernthaler, A., Pernthaler, J. & Amann, R. Fluorescence in situ hybridization and catalyzed reporter deposition for the identification of marine bacteria. Appl. Environ. Microbiol. 68, 3094–3101 (2002).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Amann, R. I., Krumholz, L. & Stahl, D. A. Fluorescent-oligonucleotide probing of whole cells for determinative, phylogenetic, and environmental studies in microbiology. J. Bacteriol. 172, 762–770 (1990).

    CAS 
    Article 

    Google Scholar
     

  • Daims, H., Brühl, A., Amann, R., Schleifer, K. & Wagner, M. The domain-specific probe EUB338 is insufficient for the detection of all bacteria: Development and evaluation of a more comprehensive probe set. Syst. Appl. Microbiol. 22, 11 (1999).

    Article 

    Google Scholar
     

  • Eilers, H., Pernthaler, J., Glockner, F. O. & Amann, R. Culturability and in situ abundance of pelagic bacteria from the North Sea. Appl. Environ. Microbiol. 66, 3044–3051 (2000).

    ADS 
    CAS 
    Article 

    Google Scholar
     

  • Manz, W., Amann, R., Vancanneyt, M., Schleifer, K.-H. & Ludwig, W. Application of a suite of 16S rRNA-specific oligonucleotide probes designed to investigate bacteria of the phylum cytophaga-flavobacter-bacteroides in the natural environment. Microbiology 142, 1097–1106. https://doi.org/10.1099/13500872-142-5-1097 (1996).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Amann, R. I., Ludwig, W. & Schleifer, K. H. Phylogenetic identification and in situ detection of individual microbial cells without cultivation. Microbiol. Rev. 59, 143–169. https://doi.org/10.1128/mr.59.1.143-169.1995 (1995).

    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Amann, R. I. et al. Combination of 16S rRNA-targeted oligonucleotide probes with flow cytometry for analyzing mixed microbial populations. Appl. Environ. Microbiol. 56, 1919–1925. https://doi.org/10.1128/AEM.56.6.1919-1925.1990 (1990).

    ADS 
    CAS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Musat, N. et al. A single-cell view on the ecophysiology of anaerobic phototrophic bacteria. Proc. Natl. Acad. Sci. USA 105, 17861–17866. https://doi.org/10.1073/pnas.0809329105 (2008).

    ADS 
    Article 
    PubMed 
    PubMed Central 

    Google Scholar
     

  • Polerecky, L. et al. Look@NanoSIMS: A tool for the analysis of nanoSIMS data in environmental microbiology. Environ. Microbiol. 14, 1009–1023. https://doi.org/10.1111/j.1462-2920.2011.02681.x (2012).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Musat, N. et al. The effect of FISH and CARD-FISH on the isotopic composition of (13)C- and (15)N-labeled Pseudomonas putida cells measured by nanoSIMS. Syst. Appl. Microbiol. 37, 267–276. https://doi.org/10.1016/j.syapm.2014.02.002 (2014).

    CAS 
    Article 
    PubMed 

    Google Scholar
     

  • Meyer, N. R., Fortney, J. L. & Dekas, A. E. NanoSIMS sample preparation decreases isotope enrichment: Magnitude, variability and implications for single-cell rates of microbial activity. Environ. Microbiol. https://doi.org/10.1111/1462-2920.15264 (2020).

    Article 
    PubMed 

    Google Scholar
     


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