Previous Article | Next Article 
Applied and Environmental Microbiology, November 2004, p. 6670-6677, Vol. 70, No. 11
0099-2240/04/$08.00+0 DOI: 10.1128/AEM.70.11.6670-6677.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
Life History Implications of rRNA Gene Copy Number in Escherichia coli
Bradley S. Stevenson and
Thomas M. Schmidt*
Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan
Received 12 March 2004/
Accepted 23 June 2004
The role of the rRNA gene copy number as a central component of bacterial life histories was studied by using strains of Escherichia coli in which one or two of the seven rRNA operons (rrnA and/or rrnB) were deleted. The relative fitness of these strains was determined in competition experiments in both batch and chemostat cultures. In batch cultures, the decrease in relative fitness corresponded to the number of rRNA operons deleted, which could be accounted for completely by increased lag times and decreased growth rates. The magnitude of the deleterious effect varied with the environment in which fitness was measured: the negative consequences of rRNA operon deletions increased under culture conditions permitting more-rapid growth. The rRNA operon deletion strains were not more effective competitors under the regimen of constant, limited resources provided in chemostat cultures. Enhanced fitness in chemostat cultures would have suggested a simple tradeoff in which deletion strains grew faster (due to more efficient resource utilization) under resource limitation. The contributions of growth rate, lag time, Ks, and death rate to the fitness of each strain were verified through mathematical simulation of competition experiments. These data support the hypothesis that multiple rRNA operons are a component of bacterial life history and that they confer a selective advantage permitting microbes to respond quickly and grow rapidly in environments characterized by fluctuations in resource availability.
* Corresponding author. Mailing address: Department of Microbiology and Molecular Genetics, Michigan State University, 6180 Biomedical Physical Sciences, East Lansing, MI 48823-4320. Phone: (517) 355-6463, ext. 1606. Fax: (517) 353-8957. E-mail:
tschmidt{at}msu.edu.
Applied and Environmental Microbiology, November 2004, p. 6670-6677, Vol. 70, No. 11
0099-2240/04/$08.00+0 DOI: 10.1128/AEM.70.11.6670-6677.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
This article has been cited by other articles:
-
Cabrera, J. E., Cagliero, C., Quan, S., Squires, C. L., Jin, D. J.
(2009). Active Transcription of rRNA Operons Condenses the Nucleoid in Escherichia coli: Examining the Effect of Transcription on Nucleoid Structure in the Absence of Transertion. J. Bacteriol.
191: 4180-4185
[Abstract]
[Full Text]
-
Ward, N. L., Challacombe, J. F., Janssen, P. H., Henrissat, B., Coutinho, P. M., Wu, M., Xie, G., Haft, D. H., Sait, M., Badger, J., Barabote, R. D., Bradley, B., Brettin, T. S., Brinkac, L. M., Bruce, D., Creasy, T., Daugherty, S. C., Davidsen, T. M., DeBoy, R. T., Detter, J. C., Dodson, R. J., Durkin, A. S., Ganapathy, A., Gwinn-Giglio, M., Han, C. S., Khouri, H., Kiss, H., Kothari, S. P., Madupu, R., Nelson, K. E., Nelson, W. C., Paulsen, I., Penn, K., Ren, Q., Rosovitz, M. J., Selengut, J. D., Shrivastava, S., Sullivan, S. A., Tapia, R., Thompson, L. S., Watkins, K. L., Yang, Q., Yu, C., Zafar, N., Zhou, L., Kuske, C. R.
(2009). Three Genomes from the Phylum Acidobacteria Provide Insight into the Lifestyles of These Microorganisms in Soils. Appl. Environ. Microbiol.
75: 2046-2056
[Abstract]
[Full Text]
-
Mileyko, Y., Joh, R. I., Weitz, J. S.
(2008). Small-scale copy number variation and large-scale changes in gene expression. Proc. Natl. Acad. Sci. USA
105: 16659-16664
[Abstract]
[Full Text]
-
Green, J. L., Bohannan, B. J. M., Whitaker, R. J.
(2008). Microbial Biogeography: From Taxonomy to Traits. Science
320: 1039-1043
[Abstract]
[Full Text]
-
Sievert, S. M., Scott, K. M., Klotz, M. G., Chain, P. S. G., Hauser, L. J., Hemp, J., Hugler, M., Land, M., Lapidus, A., Larimer, F. W., Lucas, S., Malfatti, S. A., Meyer, F., Paulsen, I. T., Ren, Q., Simon, J., the USF Genomics Class,
(2008). Genome of the Epsilonproteobacterial Chemolithoautotroph Sulfurimonas denitrificans. Appl. Environ. Microbiol.
74: 1145-1156
[Abstract]
[Full Text]
-
Silver, A. C., Rabinowitz, N. M., Kuffer, S., Graf, J.
(2007). Identification of Aeromonas veronii Genes Required for Colonization of the Medicinal Leech, Hirudo verbana. J. Bacteriol.
189: 6763-6772
[Abstract]
[Full Text]
-
Dethlefsen, L., Schmidt, T. M.
(2007). Performance of the Translational Apparatus Varies with the Ecological Strategies of Bacteria. J. Bacteriol.
189: 3237-3245
[Abstract]
[Full Text]
-
Eichorst, S. A., Breznak, J. A., Schmidt, T. M.
(2007). Isolation and Characterization of Soil Bacteria That Define Terriglobus gen. nov., in the Phylum Acidobacteria. Appl. Environ. Microbiol.
73: 2708-2717
[Abstract]
[Full Text]
-
Sorensen, K. B., Teske, A.
(2006). Stratified communities of active archaea in deep marine subsurface sediments.. Appl. Environ. Microbiol.
72: 4596-4603
[Abstract]
[Full Text]
-
Carrero-Colon, M., Nakatsu, C. H., Konopka, A.
(2006). Effect of nutrient periodicity on microbial community dynamics.. Appl. Environ. Microbiol.
72: 3175-3183
[Abstract]
[Full Text]