This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Luna, G. M.
Right arrow Articles by Danovaro, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Luna, G. M.
Right arrow Articles by Danovaro, R.
Agricola
Right arrow Articles by Luna, G. M.
Right arrow Articles by Danovaro, R.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, July 2002, p. 3509-3513, Vol. 68, No. 7
0099-2240/02/$04.00+0     DOI: 10.1128/AEM.68.7.3509-3513.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Large Fraction of Dead and Inactive Bacteria in Coastal Marine Sediments: Comparison of Protocols for Determination and Ecological Significance

G. M. Luna, E. Manini,,{dagger} and R. Danovaro*

Institute of Marine Sciences, Marine Biology Section, Faculty of Science, University of Ancona, 60131 Ancona, Italy

Received 3 January 2002/ Accepted 10 April 2002

It is now universally recognized that only a portion of aquatic bacteria is actively growing, but quantitative information on the fraction of living versus dormant or dead bacteria in marine sediments is completely lacking. We compared different protocols for the determination of the dead, dormant, and active bacterial fractions in two different marine sediments and at different depths into the sediment core. Bacterial counts ranged between (1.5 ± 0.2) x 108 cells g-1 and (53.1 ± 16.0) x 108 cells g-1 in sandy and muddy sediments, respectively. Bacteria displaying intact membrane (live bacterial cells) accounted for 26 to 30% of total bacterial counts, while dead cells represented the most abundant fraction (70 to 74%). Among living bacterial cells, nucleoid-containing cells represented only 4% of total bacterial counts, indicating that only a very limited fraction of bacterial assemblage was actively growing. Nucleoid-containing cells increased with increasing sediment organic content. The number of bacteria responsive to antibiotic treatment (direct viable count; range, 0.3 to 4.8% of the total bacterial number) was significantly lower than nucleoid-containing cell counts. An experiment of nutrient enrichment to stimulate a response of the dormant bacterial fraction determined a significant increase of nucleoid-containing cells. After nutrient enrichment, a large fraction of dormant bacteria (6 to 11% of the total bacterial number) was "reactivated." Bacterial turnover rates estimated ranged from 0.01 to 0.1 day-1 but were 50 to 80 times higher when only the fraction of active bacteria was considered (on average 3.2 day-1). Our results suggest that the fraction of active bacteria in marine sediments is controlled by nutrient supply and availability and that their turnover rates are at least 1 order of magnitude higher than previously reported.

* Corresponding author. Mailing address: Institute of Marine Science, University of Ancona, Via Brecce Bianche, 60131 Ancona, Italy. Phone: 39 71 220 4654. Fax: 39 71 220 4650. E-mail: danovaro{at}unian.it.

{dagger} Present address: Institute for the Study of Coastal Ecosystems, CNR, Lesina, 71010, Foggia, Italy.

Applied and Environmental Microbiology, July 2002, p. 3509-3513, Vol. 68, No. 7
0099-2240/02/$04.00+0     DOI: 10.1128/AEM.68.7.3509-3513.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Nocker, A., Sossa-Fernandez, P., Burr, M. D., Camper, A. K. (2007). Use of Propidium Monoazide for Live/Dead Distinction in Microbial Ecology. Appl. Environ. Microbiol. 73: 5111-5117 [Abstract] [Full Text]  
  • Rogers, S. W., Moorman, T. B., Ong, S. K. (2007). Fluorescent In Situ Hybridization and Micro-autoradiography Applied to Ecophysiology in Soil. Soil Sci. 71: 620-631 [Abstract] [Full Text]  
  • Dale, A. W., Regnier, P., Van Cappellen, P. (2006). Bioenergetic Controls on Anaerobic Oxidation of Methane (AOM) in Coastal Marine Sediments: A Theoretical Analysis. ajs 306: 246-294 [Abstract] [Full Text]  
  • Kopke, B., Wilms, R., Engelen, B., Cypionka, H., Sass, H. (2005). Microbial Diversity in Coastal Subsurface Sediments: a Cultivation Approach Using Various Electron Acceptors and Substrate Gradients. Appl. Environ. Microbiol. 71: 7819-7830 [Abstract] [Full Text]  
  • Glavin, D. P., Cleaves, H. J., Schubert, M., Aubrey, A., Bada, J. L. (2004). New Method for Estimating Bacterial Cell Abundances in Natural Samples by Use of Sublimation. Appl. Environ. Microbiol. 70: 5923-5928 [Abstract] [Full Text]  
  • Fischer, U. R., Wieltschnig, C., Kirschner, A. K. T., Velimirov, B. (2003). Does Virus-Induced Lysis Contribute Significantly to Bacterial Mortality in the Oxygenated Sediment Layer of Shallow Oxbow Lakes?. Appl. Environ. Microbiol. 69: 5281-5289 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»