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 Google Scholar
Google Scholar
Right arrow Articles by Klieve, A. V.
Right arrow Articles by Mawhinney, E. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Klieve, A. V.
Right arrow Articles by Mawhinney, E. L.
Agricola
Right arrow Articles by Klieve, A. V.
Right arrow Articles by Mawhinney, E. L.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, August 2005, p. 4248-4253, Vol. 71, No. 8
0099-2240/05/$08.00+0     doi:10.1128/AEM.71.8.4248-4253.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Naturally Occurring DNA Transfer System Associated with Membrane Vesicles in Cellulolytic Ruminococcus spp. of Ruminal Origin

Athol V. Klieve,1* Melvin T. Yokoyama,2 Robert J. Forster,3 Diane Ouwerkerk,1 Peter A. Bain,1 and Erin L. Mawhinney1

Department of Primary Industries and Fisheries, Animal Science, Yeerongpilly, Queensland, Australia,1 Department of Animal Sciences, Michigan State University, East Lansing, Michigan,2 Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada3

Received 18 October 2004/ Accepted 1 March 2005

A genetic transformation system with similarities to those reported for gram-negative bacteria was found to be associated with membrane vesicles of the ruminal cellulolytic genus Ruminococcus. Double-stranded DNA was recovered from the subcellular particulate fraction of all the cellulolytic ruminococci examined. Electron microscopy revealed that the only particles present resembled membrane vesicles. The likelihood that the DNA was associated with membrane vesicles (also known to contain cellulosomes) was further supported by the adherence of the particles associated with the subcellular DNA to cellulose powder added to culture filtrates. The particle-associated DNA comprised a population of linear molecules ranging in size from <20 kb to 49 kb (Ruminococcus sp. strain YE73) and from 23 kb to 90 kb (Ruminococcus albus AR67). Particle-associated DNA from R. albus AR67 represented DNA derived from genomic DNA of the host bacterium having an almost identical HindIII digestion pattern and an identical 16S rRNA gene. Paradoxically, particle-associated DNA was refractory to digestion with EcoRI, while the genomic DNA was susceptible to extensive digestion, suggesting that there is differential restriction modification of genomic DNA and DNA exported from the cell. Transformation using the vesicle-containing fraction of culture supernatant of Ruminococcus sp. strain YE71 was able to restore the ability to degrade crystalline cellulose to two mutants that were otherwise unable to do so. The ability was heritable and transferred to subsequent generations. It appears that membrane-associated transformation plays a role in lateral gene transfer in complex microbial ecosystems, such as the rumen.

* Corresponding author. Mailing address: Animal Research Institute, Locked Mail Bag No. 4, Moorooka, Queensland 4105, Australia. Phone: 61 7 33629483. Fax: 61 7 33629429. E-mail: athol.klieve{at}dpi.qld.gov.au.

Applied and Environmental Microbiology, August 2005, p. 4248-4253, Vol. 71, No. 8
0099-2240/05/$08.00+0     doi:10.1128/AEM.71.8.4248-4253.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.





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