AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
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 Eguchi, M.
Right arrow Articles by Cavicchioli, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Eguchi, M.
Right arrow Articles by Cavicchioli, R.
Agricola
Right arrow Articles by Eguchi, M.
Right arrow Articles by Cavicchioli, R.

Next Article 

Applied and Environmental Microbiology, November 2001, p. 4945-4954, Vol. 67, No. 11
0099-2240/01/$04.00+0   DOI: 10.1128/AEM.67.11.4945-4954.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.

Sphingomonas alaskensis Strain AFO1, an Abundant Oligotrophic Ultramicrobacterium from the North Pacific

Mitsuru Eguchi,1 Martin Ostrowski,2 Fitri Fegatella,2 John Bowman,3 David Nichols,4 Tomohiko Nishino,5 and Ricardo Cavicchioli2,*

Department of Fisheries, Kinki University, Nara 631-8505,1 and Ocean Research Institute, University of Tokyo, Nakano-ku, Tokyo 164-8639,5 Japan, and School of Microbiology & Immunology, The University of New South Wales, Sydney, UNSW 2052,2 and School of Agricultural Science3 and Antarctic CRC,4 University of Tasmania, Hobart 7001, TAS, Australia

Received 30 May 2001/Accepted 7 August 2001

Numerous studies have established the importance of picoplankton (microorganisms of <= 2 µm in length) in energy flow and nutrient cycling in marine oligotrophic environments, and significant effort has been directed at identifying and isolating heterotrophic picoplankton from the world's oceans. Using a method of diluting natural seawater to extinction followed by monthly subculturing for 12 months, a bacterium was isolated that was able to form colonies on solid medium. The strain was isolated from a 105 dilution of seawater where the standing bacterial count was 3.1 × 105 cells ml-1. This indicated that the isolate was representative of the most abundant bacteria at the sampling site, 1.5 km from Cape Muroto, Japan. The bacterium was characterized and found to be ultramicrosized (less than 0.1 µm3), and the size varied to only a small degree when the cells were starved or grown in rich media. A detailed molecular (16S rRNA sequence, DNA-DNA hybridization, G+C mol%, genome size), chemotaxonomic (lipid analysis, morphology), and physiological (resistance to hydrogen peroxide, heat, and ethanol) characterization of the bacterium revealed that it was a strain of Sphingomonas alaskensis. The type strain, RB2256, was previously isolated from Resurrection Bay, Alaska, and similar isolates have been obtained from the North Sea. The isolation of this species over an extended period, its high abundance at the time of sampling, and its geographical distribution indicate that it has the capacity to proliferate in ocean waters and is therefore likely to be an important contributor in terms of biomass and nutrient cycling in marine environments.

* Corresponding author. Mailing address: School of Microbiology and Immunology, The University of New South Wales, Sydney, UNSW 2052, Australia. Phone: 61-2-9385-3516. Fax: 61-2-9385-2742. E-mail: r.cavicchioli{at}unsw.edu.au.

Applied and Environmental Microbiology, November 2001, p. 4945-4954, Vol. 67, No. 11
0099-2240/01/$04.00+0   DOI: 10.1128/AEM.67.11.4945-4954.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 2001 by the American Society for Microbiology. All rights reserved.