European Biophysics Journal

, Volume 47, Issue 2, pp 139–149 | Cite as

The biophysics of a critical phenomenon: colonization and sedimentation of the photosynthetic bacteria Rubrivivax gelatinosus

  • Mariann Kis
  • Gábor Sipka
  • Ferhan Ayaydin
  • Péter MarótiEmail author
Original Article


In response to environmental changes, the photosynthetic bacterium Rubrivivax gelatinosus (Rvx.) can switch from a planktonic lifestyle to a phototrophic biofilm. Like in critical phenomena, the colonization and sedimentation of the cells is abrupt and hard to predict causally, and the underlying biophysics of the mechanisms involved is not known. Herein, we report basic experimental observations and quantitative explanations as keys to understanding microbial turnover of aggregates. (1) The moment of sedimentation can be controlled by the height of the tube of cultivation, by the concentrations of externally added Ficoll (a highly branched polymer) and/or of internally produced polysaccharides (constituents of the biofilm). (2) The observed translational diffusion coefficient of the planktonic bacteria is the sum of diffusion coefficients coming from random Brownian and twitching movements of the bacteria and amounts to 14 (μm)2/s. (3) This value drops hyperbolically with the association number of the cell aggregates and with the concentration of the exopolysaccharides in the biofilm. In the experiments described herein, their effects could be separated. (4) The critical conditions of colonization and sinking of the cells will be achieved if the height of the tube meets the scale height that is proportional to the ratio of the diffusion coefficient and the net mass of the bacterium. The decisive role of the web-like structure of a biofilm, the organization of bacteria from loose cooperativity to solid aggregation, and the possible importance of similar controls in other phototrophic microorganisms are discussed.


Photosynthesis Planktonic cells Sedimentation Diffusion Biofilm 








We are grateful to Prof. James Smart, University of Tennessee, Martin, USA for discussions and careful reading of the manuscript. Thanks to COST (CM1306), EFOP 3.6.2-16-2017, GINOP-2.3.2-15-2016-00001 and OTKA-K 112688 and K-17 (P.M.) for support.

Supplementary material

Movie 1 Time lapse video of colonization and sedimentation of Rvx. gelatinosus cells in cultivation tubes of different lengths. The critical phenomena occur in the leftmost (longest) tube first followed by the cultures in subsequently shorter tubes (see Fig. 3) (AVI 48042 kb)

Movie 2 Time lapse video (50 fps) of fast sinking of Rvx. gelatinosus cells induced by 5% Ficoll 400 (AVI 89426 kb)

Movie 3 Time lapse video (30 fps) of sinking of Rvx. gelatinosus cells induced by 5% Ficoll 400 in cultures of different cell concentrations: 1 × 108 cell/mL, 2.5 × 108 cell/mL and 5 × 108 cell/mL (from left to right). For comparison, the leftmost tube contains Rba. sphaeroides of 5 × 108 cell/mL concentration which does not sediment upon addition of 5% Ficoll at all. The aggregation and subsequent sedimentation begin in the rightmost tube of largest cell concentration (5 × 108 cell/mL, see Fig. 5) (AVI 38198 kb)


  1. Allen MS, Welch KT, Prebyl BS, Baker DC, Meyers AJ, Sayler GS (2004) Analysis and glycosyl composition of the exopolysaccharide isolated from the floc-forming wastewater bacterium Thauera sp. MZ1T. Environ Microbiol 6(8):780–790CrossRefPubMedGoogle Scholar
  2. Asztalos E, Italiano F, Milano F, Maróti P, Trotta M (2010) Early detection of mercury contamination by fluorescence induction of photosynthetic bacteria. Photochem Photobiol Sci 9:1218–1223CrossRefPubMedGoogle Scholar
  3. Bjarnsholt T (2013) The role of bacterial biofilms in chronic infections. APMIS Suppl 136:1–51CrossRefGoogle Scholar
  4. Chow PS, Landhäusser SM (2004) A method for routine measurements of total sugar and starch content in woody plant tissues. Tree Physiol 24:1129–1136CrossRefPubMedGoogle Scholar
  5. Costerton JW, Lappin-Scott HM (1989) Behavior of bacteria in biofilms. Am Soc Microbiol News 55:650–654Google Scholar
  6. De Philippis R, Faraloni C, Sili C, Vincenzini M (2005) Populations of exopolysaccharide-producing cyanobacteria and diatoms in the mucilaginous benthic aggregates of the Tyrrhenian Sea (Tuscan Archipelago). Sci Total Environ 353:360–368CrossRefPubMedGoogle Scholar
  7. Domb C, Lebowitz JL (2001) Phase transitions and critical phenomena, vol 19. Academic Press, San DiegoGoogle Scholar
  8. DuBois M, Gilles KA, Hamilton JK, Rebers PA, Smith F (1956) Colorimetric method for determination of sugars and related substances. Anal Chem 28(3):350–356CrossRefGoogle Scholar
  9. Flemming HC, Wingender J (2010) The biofilm matrix. Nat Rev Microbiol 8:623–633CrossRefPubMedGoogle Scholar
  10. Georgalis Y, Philipp M, Aleksandrova R, Krüger JK (2012) Light scattering studies on Ficoll PM70 solutions reveal two distinct diffusive modes. J Colloid Interface Sci 386(1):141–147CrossRefPubMedGoogle Scholar
  11. Hall-Stoodley L, Costerton JW, Stoodley P (2004) Bacterial biofilms: from the natural environment to infectious diseases. Nat Rev Microbiol 2:95–108CrossRefPubMedGoogle Scholar
  12. Hassett DJ, Korfhagen TR, Irvin RT, Schurr MJ, Sauer K, Lau GW, Sutton MD, Yu H, Hoiby N (2010) Pseudomonas aeruginosa biofilm infections in cystic fibrosis insights into pathogenic processes and treatment strategies. Expert Opin Ther Targets 14:117–130CrossRefPubMedGoogle Scholar
  13. Henrichsen J (1983) Twitching motility. Annu Rev Microbiol 37:81–93CrossRefPubMedGoogle Scholar
  14. Høiby N, Bjarnsholt T, Givskov M, Molin S, Ciofu O (2010) Antibiotic resistance of bacterial biofilms. Int J Antimicrob Agents 35(4):322–332CrossRefPubMedGoogle Scholar
  15. Imhoff JP, Trüper HG (1989) Purple nonsulfur bacteria. In: Bergey DH, Krieg NR, Holt JG (eds) Bergey’s manual of systematic bacteriology. Williams and Wilkins, Baltimore, pp 1635–1709Google Scholar
  16. Jarrell KF, McBride MJ (2008) The surprisingly diverse ways that prokaryotes move. Nat Rev Microbiol 6:466–476CrossRefPubMedGoogle Scholar
  17. Kis M, Sipka G, Asztalos E, Zs Rázga, Maróti P (2015) Purple non-sulfur photosynthetic bacteria monitor environmental stresses. J Photochem Photobiol B Biol 151:110–117CrossRefGoogle Scholar
  18. Kis M, Sipka G, Maróti P (2017) Stoichiometry and kinetics of mercury uptake by photosynthetic bacteria. Photosynth Res 132(2):197–209CrossRefPubMedGoogle Scholar
  19. Lear G, Lewis GD (eds) (2012) Microbial biofilms: current research and applications. Caister Academic Press, Norfolk, UK. ISBN 978-1-904455-96-7Google Scholar
  20. Liao Q, Wang Y-J, Wang Y-Z, Zhu X, Tian X, Li J (2010) Formation and hydrogen production of photosynthetic bacterial biofilm under various illumination conditions. Biores Technol 101:5315–5324CrossRefGoogle Scholar
  21. McDougald D, Rice SA, Barraud N, Steinberg PD, Kjelleberg S (2012) Should we stay or should we go: mechanisms and ecological consequences for biofilm dispersal. Nat Rev Micro 10:39–50CrossRefGoogle Scholar
  22. Nadell CD, Xavier JB, Foster KR (2009) The sociobiology of biofilms. FEMS Microbiol Rev 33(1):206–224CrossRefPubMedGoogle Scholar
  23. Nishimori H, Ortiz G (2010) Elements of phase transitions and critical phenomena. Oxford University Press, OxfordCrossRefGoogle Scholar
  24. Overmann J, Lehmann S, Pfennig N (1991) Gas vesicle formation and buoyancy regulation in Pelodictyon phaeoclathratiforme (Green sulphur bacteria). Arch Microbiol 157:29–37CrossRefGoogle Scholar
  25. Roeselers G, Norris TB, Castenholz RW, Rysgaard S, Glud RN, Kühl M, Muyzer G (2007) Diversity of phototrophic bacteria in microbial mats from Arctic hot springs (Greenland). Environ Microbiol 9(1):26–38CrossRefPubMedGoogle Scholar
  26. Roeselers G, Loosdrecht MC, Muyzer G (2008) Phototrophic biofilms and their potential applications. J Appl Phycol 20:227–235CrossRefPubMedGoogle Scholar
  27. Steunou AS, Liotenberg S, Soler M-N, Briandet R, Barbe V, Astier Ch, Ouchane S (2013) EmbRS a new two-component system that inhibits biofilm formation and saves Rubrivivax gelatinosus from sinking. Microbiol Open 2(3):431–446CrossRefGoogle Scholar
  28. Williams P, Winzer K, Chan WC, Camara M (2007) Look who’s talking: communication and quorum sensing in the bacterial world. Philos Trans R Soc Lond B Biol Sci 362:1119–1134CrossRefPubMedPubMedCentralGoogle Scholar
  29. Yildiz FH, Visick KL (2009) Vibrio biofilms: so much the same yet so different. Trends Microbiol 17:109–118CrossRefPubMedPubMedCentralGoogle Scholar

Copyright information

© European Biophysical Societies' Association 2017

Authors and Affiliations

  • Mariann Kis
    • 1
  • Gábor Sipka
    • 1
    • 2
  • Ferhan Ayaydin
    • 2
  • Péter Maróti
    • 1
    Email author
  1. 1.Institute of Medical Physics, University of SzegedSzegedHungary
  2. 2.Biological Research CenterHungarian Academy of SciencesSzegedHungary

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