Effects of Saharan dust on the microbial community during a large in situ mesocosm experiment in the NW Mediterranean Sea

M. Laghdass, S. Blain, M. Besseling, P. Catala, Cecile Guieu, I. Obernosterer

Research output: Contribution to journalArticle

Abstract

The response of the microbial community to Saharan dust deposition was investigated in 6 large mesocosms (52 m3) deployed at an oligotrophic coastal site in the NW Mediterranean Sea in June 2008 (DUNE project). The mesocosms represented well the environmental conditions observed at the study site during the 8 d experimental period, and the triplicate mesocosms exhibited high reproducibility for each treatment. Dust deposition resulted in an increase in chlorophyll a concentration (0.22 ± 0.03 μg l-1), as compared to that in the control treatments (0.12 ± 0.01 μg l -1), but no treatment effect was observed for bacterial heterotrophic abundance at 5 m depth. Results from the fingerprinting technique CE-SSCP indicate a temporal evolution of the structure of the total (16S rRNA gene) and active (16S rRNA transcripts) bacterial community, and Saharan dust deposition had a noticeable structuring effect on the active bacterial community. Combining results from 16S rRNA gene clone libraries and CE-SSCP indicates that the relative contribution of Alteromonas macleodii to the active bacterial community was enhanced 2-fold following dust addition. The 2 operational taxonomic units (OTUs) Thiothrix and Alteromonas, belonging to Gammaproteobacteria, and the Bacteroidetes OTU NS5-1 were specific to the clone libraries from the dust-amended mesocosms or more abundant in these than in the control ones. CARD-FISH analyses, however, indicate that these OTUs had overall low abundances (1 to 5% of total DAPI-counts). Despite the pronounced temporal trend observed during the experimental period, dust deposition had a small, but noticeable structuring effect on the heterotrophic bacterial community that was detectable only at the OTU level at 99% similarity of the 16S rRNA gene.

Original languageEnglish (US)
Pages (from-to)201-213
Number of pages13
JournalAquatic Microbial Ecology
Volume62
Issue number2
DOIs
StatePublished - Jan 19 2011

Fingerprint

mesocosm
Mediterranean Sea
dust
microbial communities
microbial community
bacterial communities
ribosomal RNA
experiment
gene
clone
Thiothrix
Alteromonas macleodii
Alteromonas
clones
genes
gamma-Proteobacteria
temporal evolution
reproducibility
in situ
effect

Keywords

  • Alteromonas macleodii
  • CARD-FISH
  • CE-SSCP
  • Clone libraries
  • In situ mesocosms
  • NW Mediterranean Sea
  • Saharan dust deposition

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Aquatic Science

Cite this

Effects of Saharan dust on the microbial community during a large in situ mesocosm experiment in the NW Mediterranean Sea. / Laghdass, M.; Blain, S.; Besseling, M.; Catala, P.; Guieu, Cecile; Obernosterer, I.

In: Aquatic Microbial Ecology, Vol. 62, No. 2, 19.01.2011, p. 201-213.

Research output: Contribution to journalArticle

Laghdass, M. ; Blain, S. ; Besseling, M. ; Catala, P. ; Guieu, Cecile ; Obernosterer, I. / Effects of Saharan dust on the microbial community during a large in situ mesocosm experiment in the NW Mediterranean Sea. In: Aquatic Microbial Ecology. 2011 ; Vol. 62, No. 2. pp. 201-213.
@article{2ab4dd453416451da296736b70ada498,
title = "Effects of Saharan dust on the microbial community during a large in situ mesocosm experiment in the NW Mediterranean Sea",
abstract = "The response of the microbial community to Saharan dust deposition was investigated in 6 large mesocosms (52 m3) deployed at an oligotrophic coastal site in the NW Mediterranean Sea in June 2008 (DUNE project). The mesocosms represented well the environmental conditions observed at the study site during the 8 d experimental period, and the triplicate mesocosms exhibited high reproducibility for each treatment. Dust deposition resulted in an increase in chlorophyll a concentration (0.22 ± 0.03 μg l-1), as compared to that in the control treatments (0.12 ± 0.01 μg l -1), but no treatment effect was observed for bacterial heterotrophic abundance at 5 m depth. Results from the fingerprinting technique CE-SSCP indicate a temporal evolution of the structure of the total (16S rRNA gene) and active (16S rRNA transcripts) bacterial community, and Saharan dust deposition had a noticeable structuring effect on the active bacterial community. Combining results from 16S rRNA gene clone libraries and CE-SSCP indicates that the relative contribution of Alteromonas macleodii to the active bacterial community was enhanced 2-fold following dust addition. The 2 operational taxonomic units (OTUs) Thiothrix and Alteromonas, belonging to Gammaproteobacteria, and the Bacteroidetes OTU NS5-1 were specific to the clone libraries from the dust-amended mesocosms or more abundant in these than in the control ones. CARD-FISH analyses, however, indicate that these OTUs had overall low abundances (1 to 5{\%} of total DAPI-counts). Despite the pronounced temporal trend observed during the experimental period, dust deposition had a small, but noticeable structuring effect on the heterotrophic bacterial community that was detectable only at the OTU level at 99{\%} similarity of the 16S rRNA gene.",
keywords = "Alteromonas macleodii, CARD-FISH, CE-SSCP, Clone libraries, In situ mesocosms, NW Mediterranean Sea, Saharan dust deposition",
author = "M. Laghdass and S. Blain and M. Besseling and P. Catala and Cecile Guieu and I. Obernosterer",
year = "2011",
month = "1",
day = "19",
doi = "10.3354/ame01466",
language = "English (US)",
volume = "62",
pages = "201--213",
journal = "Aquatic Microbial Ecology",
issn = "0948-3055",
publisher = "Inter-Research",
number = "2",

}

TY - JOUR

T1 - Effects of Saharan dust on the microbial community during a large in situ mesocosm experiment in the NW Mediterranean Sea

AU - Laghdass, M.

AU - Blain, S.

AU - Besseling, M.

AU - Catala, P.

AU - Guieu, Cecile

AU - Obernosterer, I.

PY - 2011/1/19

Y1 - 2011/1/19

N2 - The response of the microbial community to Saharan dust deposition was investigated in 6 large mesocosms (52 m3) deployed at an oligotrophic coastal site in the NW Mediterranean Sea in June 2008 (DUNE project). The mesocosms represented well the environmental conditions observed at the study site during the 8 d experimental period, and the triplicate mesocosms exhibited high reproducibility for each treatment. Dust deposition resulted in an increase in chlorophyll a concentration (0.22 ± 0.03 μg l-1), as compared to that in the control treatments (0.12 ± 0.01 μg l -1), but no treatment effect was observed for bacterial heterotrophic abundance at 5 m depth. Results from the fingerprinting technique CE-SSCP indicate a temporal evolution of the structure of the total (16S rRNA gene) and active (16S rRNA transcripts) bacterial community, and Saharan dust deposition had a noticeable structuring effect on the active bacterial community. Combining results from 16S rRNA gene clone libraries and CE-SSCP indicates that the relative contribution of Alteromonas macleodii to the active bacterial community was enhanced 2-fold following dust addition. The 2 operational taxonomic units (OTUs) Thiothrix and Alteromonas, belonging to Gammaproteobacteria, and the Bacteroidetes OTU NS5-1 were specific to the clone libraries from the dust-amended mesocosms or more abundant in these than in the control ones. CARD-FISH analyses, however, indicate that these OTUs had overall low abundances (1 to 5% of total DAPI-counts). Despite the pronounced temporal trend observed during the experimental period, dust deposition had a small, but noticeable structuring effect on the heterotrophic bacterial community that was detectable only at the OTU level at 99% similarity of the 16S rRNA gene.

AB - The response of the microbial community to Saharan dust deposition was investigated in 6 large mesocosms (52 m3) deployed at an oligotrophic coastal site in the NW Mediterranean Sea in June 2008 (DUNE project). The mesocosms represented well the environmental conditions observed at the study site during the 8 d experimental period, and the triplicate mesocosms exhibited high reproducibility for each treatment. Dust deposition resulted in an increase in chlorophyll a concentration (0.22 ± 0.03 μg l-1), as compared to that in the control treatments (0.12 ± 0.01 μg l -1), but no treatment effect was observed for bacterial heterotrophic abundance at 5 m depth. Results from the fingerprinting technique CE-SSCP indicate a temporal evolution of the structure of the total (16S rRNA gene) and active (16S rRNA transcripts) bacterial community, and Saharan dust deposition had a noticeable structuring effect on the active bacterial community. Combining results from 16S rRNA gene clone libraries and CE-SSCP indicates that the relative contribution of Alteromonas macleodii to the active bacterial community was enhanced 2-fold following dust addition. The 2 operational taxonomic units (OTUs) Thiothrix and Alteromonas, belonging to Gammaproteobacteria, and the Bacteroidetes OTU NS5-1 were specific to the clone libraries from the dust-amended mesocosms or more abundant in these than in the control ones. CARD-FISH analyses, however, indicate that these OTUs had overall low abundances (1 to 5% of total DAPI-counts). Despite the pronounced temporal trend observed during the experimental period, dust deposition had a small, but noticeable structuring effect on the heterotrophic bacterial community that was detectable only at the OTU level at 99% similarity of the 16S rRNA gene.

KW - Alteromonas macleodii

KW - CARD-FISH

KW - CE-SSCP

KW - Clone libraries

KW - In situ mesocosms

KW - NW Mediterranean Sea

KW - Saharan dust deposition

UR - http://www.scopus.com/inward/record.url?scp=79956306196&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79956306196&partnerID=8YFLogxK

U2 - 10.3354/ame01466

DO - 10.3354/ame01466

M3 - Article

AN - SCOPUS:79956306196

VL - 62

SP - 201

EP - 213

JO - Aquatic Microbial Ecology

JF - Aquatic Microbial Ecology

SN - 0948-3055

IS - 2

ER -