1887

Microbiology Society logo

Volume 144, Issue 2

Floc stability and adhesion of green-fluorescent-protein-marked bacteria to flocs in activated sludge Free

Abstract

Wastewater is often treated using the activated sludge process. Flocculation and subsequent sedimentation of flocs are vital steps in this process that have direct influence on the quality of the effluent water from wastewater treatment plants. Since cells that remain free-living will decrease the quality of the effluent water it is important to understand the mechanisms of bacterial adhesion to flocs. The green fluorescent protein (GFP) was used as a cellular marker to study bacterial adhesion to activated sludge flocs in sludge liquor. Cell surface hydrophobicity (CSH) was shown to be an important factor that determined the relative bacterial adhesion potential. High CSH correlated with high numbers of attached cells. However, the absolute adhesion of two test bacteria to different sludge flocs varied and could not be explained by the floc characteristics. Confocal laser scanning microscopy of GFP-marked cells showed their position in the floc matrix . Hydrophobic cells attached not only on the surface but also within the floc, whereas hydrophilic cells did not. This indicates that cells may penetrate the flocs through channels and pores and increase the effective surface, which in turn makes the clarification of the wastewater effluent more efficient. The addition of polymers is common practice in wastewater treatment and was shown to increase bacterial adhesion to the flocs. A decrease in surface tension caused by addition of DMSO decreased adhesion, indicating the detrimental effect of surfactants on flocculation. An understanding of basic bacterial adhesion and aggregation mechanisms is important for the managment and control of biotechnological wastewater treatment.

  • Received:
  • Accepted:
  • Revised:
  • Published Online:
Keyword(s): activated sludge flocs , bacterial adhesion , cell surface hydrophobicity , green fluorescent protein and wastewater
© Society for General Microbiology 1998
Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-144-2-519
1998-02-01
2024-04-26
Loading full text...

Full text loading...

/deliver/fulltext/micro/144/2/mic-144-2-519.html?itemId=/content/journal/micro/10.1099/00221287-144-2-519&mimeType=html&fmt=ahah

References

  1. Absolom D. R., Lamberti F. V., Policova Z., Zingg W., van Oss C. J., Neumann A. W. 1983; Surface thermodynamics of bacterial adhesion.. Appl Environ Microbiol 46:90–97
     [Google Scholar]
  2. Andreasen M. 1997 GFP-marking of marine plasmids MSc thesis The Technical University of Denmark;
     [Google Scholar]
  3. Ausubel F. M., Brent R., Kingston R. E., Moore D. D., Seidman J. G., Smith J. A., Struhl K. 1989 Current Protocols in Molecular Biology New York: John Wiley;
     [Google Scholar]
  4. Bar-Ness R., Rosenberg M. 1989; Putative role of a 70 kDa outer-surface protein in promoting cell-surface hydrophobicity of Serratia marcescens RZ.. J Gen Microbiol 135:2277–2281
     [Google Scholar]
  5. Busscher H. J., Weerkamp A. H., van der Mei H. C., van Pelt A. W. J., de Jong H. P., Arends J. 1984; Measurement of the surface free energy of bacterial cell surfaces and its relevance for adhesion.. Appl Environ Microbiol 48:980–983
     [Google Scholar]
  6. Chalfie M., Tu Y., Euskirchen G., Ward W. W., Prasher D. C. 1994; Green fluorescent protein as a marker for gene expression.. Science 263:802–804
     [Google Scholar]
  7. Christensen B. B., Sternberg C., Molin S. 1997; Bacterial plasmid conjugation on semi-solid surfaces monitored with the green fluorescent protein (GFP) from Aequarea victoria as a marker.. Gene 173:59–65
     [Google Scholar]
  8. Duncan-Hewitt W. C. 1990 Nature of the hydrophobic effect.. In Microbial Cell Surface Hydrophobicity pp 40–73 Edited by Doyle R. J., Rosenberg M. Washington, DC: American Society for Microbiology;
     [Google Scholar]
  9. Eberl L., Schultze R., Ammendola A., Geisenberger O., Erhart R., Sternberg C., Molin S., Amann R. 1997; Use of green fluorescent protein as a marker for ecological studies of activated sludge communities.. FEMS Microbiol Lett 149:77–83
     [Google Scholar]
  10. Eriksson L., Steen I., Tendaj M. 1992; Evaluation of sludge properties at an activated sludge plant.. Water Sci Technol 25:251–265
     [Google Scholar]
  11. Forster C. F. 1971; Activated sludge surfaces in relation to the sludge volume index.. Water Res 5:861–870
     [Google Scholar]
  12. Forster C. F., Dallas-Newton J. 1980; Activated sludge settlement – some suppositions and suggestions.. Water Pollut Control338–351
     [Google Scholar]
  13. Hermansson M., Kjelleberg S., Korhonen T., Stenström T. -A. 1982; Hydrophobic and electrostatic characterisation of surface structures of bacteria and its relationship to adhesion at an air–water interface.. Arch Microbiol 131:308–312
     [Google Scholar]
  14. Jorand F., Guicherd P., Urbain V., Manem J., Block J. C. 1994; Hydrophobicity of activated sludge flocs and laboratory grown bacteria.. Water Sci Technol 30:211–218
     [Google Scholar]
  15. Li D. -h. 1990; Structure of activated sludge flocs.. Biotechnol Bioeng 35:57–65
     [Google Scholar]
  16. Loosdrecht M. C. M., v., Lyklema J., Norde W., Zehnder A. J. B. 1989; Bacterial adhesion: a physicochemical approach.. Microb Ecol 17:1–15
     [Google Scholar]
  17. Marshall K. C., Stout R., Mitchell R. 1971; Mechanism of the initial events in the sorption of marine bacteria to surfaces.. J Gen Microbiol 68:337–348
     [Google Scholar]
  18. Ørskov I., Ørskov F., Jann B., Jann K. 1977; Serology, chemistry, and genetics of O and K antigens of Escherichia coli . Bacteriol Rev 41:667–710
     [Google Scholar]
  19. Rosenberg M., Kjelleberg S. 1986; Hydrophobic interaction: role in bacterial adhesion.. Adv Microb Ecol 9:353–393
     [Google Scholar]
  20. Stenström T. -A., Kjelleberg S. 1985; Fimbriae mediated non-specific adhesion of Salmonella typhimurium to mineral particles.. Arch Microbiol 143:6–10
     [Google Scholar]
  21. Thaveesri J., Daffonchio D., Liessens B., Vandermeren P., Verstraete W. 1995; Granulation and sludge bed stability in upflow anaerobic sludge bed reactors in relation to surface thermodynamics.. Appl Environ Microbiol 61:3681–3686
     [Google Scholar]
  22. Urbain V., Block J. C., Manem J. 1993; Bioflocculation activated sludge: an analytical approach.. Water Res 27:829–838
     [Google Scholar]
  23. Valin S. D., Sutherland D. J. 1982; Predicting bioflocculation: new developements in the application of flocculation theory.. Environ Technol Lett 3:363–374
     [Google Scholar]
  24. Zita A., Hermansson M. 1994; Effects of ionic strength on bacterial adhesion and stability of flocs in a wastewater activated sludge system.. Appl Environ Microbiol 60:3041–3048
     [Google Scholar]
  25. Zita A., Hermansson M. 1997a; Determination of bacterial cell surface hydrophobicity of single cells in cultures and in wastewater in situ . FEMS Microbiol Lett 152:299–306
     [Google Scholar]
  26. Zita A., Hermansson M. 1997b; Effects of bacterial cell surface structures and hydrophobicity on attachment to activated sludge flocs.. Appl Environ Microbiol 63:1168–1170
     [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-144-2-519
Loading
Floc stability and adhesion of green-fluorescent-protein-marked bacteria to flocs in activated sludge
Microbiology 144, 519 (1998); https://doi.org/10.1099/00221287-144-2-519
/content/journal/micro/10.1099/00221287-144-2-519
/content/journal/micro/10.1099/00221287-144-2-519
Loading

Data & Media loading...

Most cited Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error