Quick Search:

uzh logo
Browse by:
bullet
bullet
bullet
bullet

Zurich Open Repository and Archive

Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-14299

Fazi, S; Amalfitano, S; Piccini, C; Zoppini, A; Puddu, A; Pernthaler, J (2008). Colonization of overlaying water by bacteria from dry river sediments. Environmental Microbiology, 10(10):2760-2772.

[img] PDF - Registered users only
1MB

View at publisher
[img]
Preview
Accepted Version
PDF
1MB

Abstract

We studied the diversity, community composition and activity of the primary microbial colonizers of the water above freshly re-wetted sediments from a temporary river. Dried sediments, collected from Mulargia River (Sardinia, Italy), were covered with sterile freshwater in triplicate microcosms, and changes of the planktonic microbial assemblage were monitored over a 48 h period. During the first 9 h bacterial abundance was low (1.5 x 10(4) cells ml(-1)); it increased to 3.4 x 10(6) cells ml(-1) after 28 h and did not change thereafter. Approximately 20% of bacteria exhibited DNA de novo synthesis already after 9 h of incubation. Changes of the ratios of (3)H-leucine to (3)H-thymidine incorporation rates indicated a shift of growth patterns during the experiment. Extracellular enzyme activity showed a maximum at 48 h with aminopeptidase activity (430.8 +/- 22.6 nmol MCA l(-1) h(-1)) significantly higher than alkaline phosphatase (98.6 +/- 4.3 nmol MUF l(-1) h(-1)). The primary microbial colonizers of the overlaying water - as determined by 16S rRNA gene sequence analysis - were related to at least six different phylogenetic lineages of Bacilli and to Alphaproteobacteria (Brevundimonas spp. and Caulobacter spp.). Large bacterial cells affiliated to one clade of Bacillus sp. were rare in the dried sediments, but constituted the majority of the planktonic microbial assemblage and of cells with detectable DNA-synthesis until 28 h after re-wetting. Their community contribution decreased in parallel with a rise of flagellated and ciliated protists. Estimates based on cell production rates suggested that the rapidly enriched Bacillus sp. suffered disproportionally high loss rates from selective predation, thus favouring the establishment of a more heterogenic assemblage of microbes (consisting of Proteobacteria, Actinobacteria and Cytophaga-Flavobacteria). Our results suggest that the primary microbial colonizers of the water above dried sediments are passively released into the plankton and that their high growth potential is counteracted by the activity of bacterivorous protists.

Citations

21 citations in Web of Science®
20 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

57 downloads since deposited on 19 Feb 2009
14 downloads since 12 months

Detailed statistics

Additional indexing

Contributors:
Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Institute of Plant Biology
DDC:580 Plants (Botany)
Language:English
Date:October 2008
Deposited On:19 Feb 2009 20:38
Last Modified:28 Nov 2013 02:10
Publisher:Wiley-Blackwell
ISSN:1462-2912
Additional Information:The definitive version is available at www.blackwell-synergy.com
Publisher DOI:10.1111/j.1462-2920.2008.01695.x
PubMed ID:18643927

Users (please log in): suggest update or correction for this item

Repository Staff Only: item control page