Community Structure and Activity of a Highly Dynamic and Nutrient-Limited Hypersaline Microbial Mat in Um Alhool Sabkha, Qatar

Handle URI:
http://hdl.handle.net/10754/550536
Title:
Community Structure and Activity of a Highly Dynamic and Nutrient-Limited Hypersaline Microbial Mat in Um Alhool Sabkha, Qatar
Authors:
Al-Thani, Roda; Alnajjar, Mohammad Ahmad ( 0000-0003-4861-1604 ) ; Al-Raei, Abdul Munem; Ferdelman, Tim; Thang, Nguyen M.; Shaikh, Ismail Al; Al-Ansi, Mehsin; de Beer, Dirk
Abstract:
The Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below as it is surrounded by sand dunes. We investigated the chemical composition, the microbial activity and biodiversity of the four main layers (L1–L4) in the photosynthetic mats. Chlorophyll a (Chl a) concentration and distribution (measured by HPLC and hyperspectral imaging, respectively), the phycocyanin distribution (scanned with hyperspectral imaging), oxygenic photosynthesis (determined by microsensor), and the abundance of photosynthetic microorganisms (from 16S and 18S rRNA sequencing) decreased with depth in the euphotic layer (L1). Incident irradiance exponentially attenuated in the same zone reaching 1% at 1.7-mm depth. Proteobacteria dominated all layers of the mat (24%–42% of the identified bacteria). Anoxygenic photosynthetic bacteria (dominated by Chloroflexus) were most abundant in the third red layer of the mat (L3), evidenced by the spectral signature of Bacteriochlorophyll as well as by sequencing. The deep, black layer (L4) was dominated by sulfate reducing bacteria belonging to the Deltaproteobacteria, which were responsible for high sulfate reduction rates (measured using 35S tracer). Members of Halobacteria were the dominant Archaea in all layers of the mat (92%–97%), whereas Nematodes were the main Eukaryotes (up to 87%). Primary productivity rates of Um Alhool mat were similar to those of other hypersaline microbial mats. However, sulfate reduction rates were relatively low, indicating that oxygenic respiration contributes more to organic material degradation than sulfate reduction, because of bioturbation. Although Um Alhool hypersaline mat is a nutrient-limited ecosystem, it is interestingly dynamic and phylogenetically highly diverse. All its components work in a highly efficient and synchronized way to compensate for the lack of nutrient supply provided during regular inundation periods.
KAUST Department:
Red Sea Research Center (RSRC)
Citation:
Community Structure and Activity of a Highly Dynamic and Nutrient-Limited Hypersaline Microbial Mat in Um Alhool Sabkha, Qatar 2014, 9 (3):e92405 PLoS ONE
Publisher:
Public Library of Science (PLoS)
Journal:
PLoS ONE
Issue Date:
21-Mar-2014
DOI:
10.1371/journal.pone.0092405
Type:
Article
ISSN:
1932-6203
Additional Links:
http://dx.plos.org/10.1371/journal.pone.0092405
Appears in Collections:
Articles; Red Sea Research Center (RSRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorAl-Thani, Rodaen
dc.contributor.authorAlnajjar, Mohammad Ahmaden
dc.contributor.authorAl-Raei, Abdul Munemen
dc.contributor.authorFerdelman, Timen
dc.contributor.authorThang, Nguyen M.en
dc.contributor.authorShaikh, Ismail Alen
dc.contributor.authorAl-Ansi, Mehsinen
dc.contributor.authorde Beer, Dirken
dc.date.accessioned2015-04-23T14:19:18Zen
dc.date.available2015-04-23T14:19:18Zen
dc.date.issued2014-03-21en
dc.identifier.citationCommunity Structure and Activity of a Highly Dynamic and Nutrient-Limited Hypersaline Microbial Mat in Um Alhool Sabkha, Qatar 2014, 9 (3):e92405 PLoS ONEen
dc.identifier.issn1932-6203en
dc.identifier.doi10.1371/journal.pone.0092405en
dc.identifier.urihttp://hdl.handle.net/10754/550536en
dc.description.abstractThe Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below as it is surrounded by sand dunes. We investigated the chemical composition, the microbial activity and biodiversity of the four main layers (L1–L4) in the photosynthetic mats. Chlorophyll a (Chl a) concentration and distribution (measured by HPLC and hyperspectral imaging, respectively), the phycocyanin distribution (scanned with hyperspectral imaging), oxygenic photosynthesis (determined by microsensor), and the abundance of photosynthetic microorganisms (from 16S and 18S rRNA sequencing) decreased with depth in the euphotic layer (L1). Incident irradiance exponentially attenuated in the same zone reaching 1% at 1.7-mm depth. Proteobacteria dominated all layers of the mat (24%–42% of the identified bacteria). Anoxygenic photosynthetic bacteria (dominated by Chloroflexus) were most abundant in the third red layer of the mat (L3), evidenced by the spectral signature of Bacteriochlorophyll as well as by sequencing. The deep, black layer (L4) was dominated by sulfate reducing bacteria belonging to the Deltaproteobacteria, which were responsible for high sulfate reduction rates (measured using 35S tracer). Members of Halobacteria were the dominant Archaea in all layers of the mat (92%–97%), whereas Nematodes were the main Eukaryotes (up to 87%). Primary productivity rates of Um Alhool mat were similar to those of other hypersaline microbial mats. However, sulfate reduction rates were relatively low, indicating that oxygenic respiration contributes more to organic material degradation than sulfate reduction, because of bioturbation. Although Um Alhool hypersaline mat is a nutrient-limited ecosystem, it is interestingly dynamic and phylogenetically highly diverse. All its components work in a highly efficient and synchronized way to compensate for the lack of nutrient supply provided during regular inundation periods.en
dc.publisherPublic Library of Science (PLoS)en
dc.relation.urlhttp://dx.plos.org/10.1371/journal.pone.0092405en
dc.rightsThis is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.en
dc.titleCommunity Structure and Activity of a Highly Dynamic and Nutrient-Limited Hypersaline Microbial Mat in Um Alhool Sabkha, Qataren
dc.typeArticleen
dc.contributor.departmentRed Sea Research Center (RSRC)en
dc.identifier.journalPLoS ONEen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Biological and Environmental Sciences, Qatar University, Doha, Qataren
dc.contributor.institutionMax-Planck Institute for Marine Microbiology, Bremen, Germanyen
dc.contributor.institutionEnvironmental Studies Center, Qatar University, Doha, Qataren
kaust.authorAlnajjar, Mohammad Ahmaden
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