Display options
Share it on

Front Microbiol. 2016 Jun 14;7:903. doi: 10.3389/fmicb.2016.00903. eCollection 2016.

Flow Cytometric Assessment of Bacterial Abundance in Soils, Sediments and Sludge.

Frontiers in microbiology

Aline Frossard, Frederik Hammes, Mark O Gessner

Affiliations

  1. Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL)Birmensdorf Switzerland; Department of Aquatic Ecology, Swiss Federal Institute of Aquatic Science and Technology (Eawag)Dübendorf Switzerland; Department of Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), StechlinGermany; Institute of Integrative Biology (IBZ), ETH ZürichZürich Switzerland.
  2. Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag) Dübendorf Switzerland.
  3. Department of Aquatic Ecology, Swiss Federal Institute of Aquatic Science and Technology (Eawag)Dübendorf Switzerland; Department of Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), StechlinGermany; Institute of Integrative Biology (IBZ), ETH ZürichZürich Switzerland; Department of Ecology, Berlin Institute of Technology (TU Berlin)Berlin Germany.

PMID: 27379043 PMCID: PMC4905975 DOI: 10.3389/fmicb.2016.00903

Abstract

Bacterial abundance is a fundamental measure in microbiology, but its assessment is often tedious, especially for soil, and sediment samples. To overcome this limitation, we adopted a time-efficient flow-cytometric (FCM) counting method involving cell detachment and separation from matrix particles by centrifugation in tubes receiving sample suspensions and Histodenz(®) solution. We used this approach to assess bacterial abundances in diverse soils (natural and agricultural), sediments (streams and lakes) and sludge from sand-filters in a drinking water treatment plant and compared the results to bacterial abundances determined by two established methods, epifluorescence microscopy (EM) and adenosine triphosphate (ATP) quantification. Cell abundances determined by FCM and EM correlated fairly well, although absolute cell abundances were generally lower when determined by FCM. FCM also showed significant relations with cell counts converted from ATP concentrations, although estimates derived from ATP determinations were typically higher, indicating the presence of ATP sources other than bacteria. Soil and sediment organic matter (OM) content influenced the goodness of fit between counts obtained with EM and FCM. In particular, bacterial abundance determined by FCM in samples containing less than 10% OM, such as stream sediment, was particularly well correlated with the cell counts assessed by EM. Overall, these results suggest that FCM following cell detachment and purification is a useful approach to increase sample throughput for determining bacterial abundances in soils, sediments and sludge. However, notable scatter and only partial concordance among the FCM and reference methods suggests that protocols require further improvement for assessments requiring high precision, especially when OM contents in samples are high.

Keywords: ATP; bacterial abundance; drinking water treatment plant sand-filters; epifluorescence microscopy; flow cytometry; sediment; soil

References

  1. Res Microbiol. 2008 Jun;159(5):390-9 - PubMed
  2. Curr Opin Microbiol. 2008 Jun;11(3):205-12 - PubMed
  3. Microbiol Rev. 1994 Dec;58(4):603-15 - PubMed
  4. Cytometry B Clin Cytom. 2006 May;70(3):149-53 - PubMed
  5. FEMS Microbiol Ecol. 2003 May 1;44(1):3-15 - PubMed
  6. Water Res. 2013 Dec 1;47(19):7131-42 - PubMed
  7. Anal Bioanal Chem. 2010 Jun;397(3):1083-95 - PubMed
  8. Proc Natl Acad Sci U S A. 1998 Jun 9;95(12):6578-83 - PubMed
  9. Extremophiles. 2009 Jul;13(4):583-94 - PubMed
  10. Nat Rev Microbiol. 2011 Feb;9(2):119-30 - PubMed
  11. Microb Ecol. 1994 Sep;28(2):195-9 - PubMed
  12. Trends Biotechnol. 2012 Sep;30(9):475-84 - PubMed
  13. Nat Methods. 2012 Jul;9(7):671-5 - PubMed
  14. Environ Microbiol. 2013 Oct;15(10):2841-9 - PubMed
  15. J Microbiol Methods. 2003 Oct;55(1):201-11 - PubMed
  16. Microbiol Rev. 1980 Dec;44(4):739-96 - PubMed
  17. J Microbiol Methods. 2014 Aug;103:9-17 - PubMed
  18. Microbiol Rev. 1995 Mar;59(1):143-69 - PubMed
  19. Appl Environ Microbiol. 1997 Jan;63(1):186-93 - PubMed
  20. Trends Biotechnol. 2010 Aug;28(8):416-24 - PubMed
  21. Environ Sci Technol. 2005 May 1;39(9):3289-94 - PubMed
  22. Microb Ecol. 1987 Mar;13(2):95-101 - PubMed
  23. J Microbiol Methods. 2008 Oct;75(2):237-43 - PubMed
  24. Appl Environ Microbiol. 2003 May;69(5):2631-7 - PubMed
  25. J Microbiol Methods. 2009 Nov;79(2):246-9 - PubMed
  26. J Microbiol Methods. 2006 Mar;64(3):316-32 - PubMed
  27. PCR Methods Appl. 1995 Feb;4(4):234-8 - PubMed
  28. J Microbiol Methods. 2014 Mar;98:35-40 - PubMed
  29. Ecology. 2007 Jun;88(6):1354-64 - PubMed
  30. Microbes Environ. 2013;28(1):3-12 - PubMed
  31. Water Res. 2010 Jul;44(13):3915-23 - PubMed
  32. Microb Ecol. 2007 May;53(4):513-23 - PubMed
  33. Appl Environ Microbiol. 1993 Oct;59(10):3327-33 - PubMed
  34. J Microbiol Methods. 2014 Oct;105:31-8 - PubMed

Publication Types