Eukaryotic diversity of miers valley hypoliths
>Magister Scientiae - MSc The extreme conditions of Antarctic desert soils render this environment selective towards a diverse range of psychrotrophic microbial communities. Cracks and fissures in translucent quartz rocks permit an adequate amount of penetrating light, sufficient water and nutrie...
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2012
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ftunivwesterncap:oai:etd.uwc.ac.za:11394/4031 2023-05-15T14:02:11+02:00 Eukaryotic diversity of miers valley hypoliths Keriuscia Gokul, Jarishma Cowan, D. A. Tuffin, Marla Stomeo, F. 2012 http://hdl.handle.net/11394/4031 en eng University of the Western Cape http://hdl.handle.net/11394/4031 University of the Western Cape Hypolith Antarctic Dry Valleys Microbial diversity DGGE T-RFLP Culture independent ITS 18S Microalgae Thesis 2012 ftunivwesterncap 2021-06-17T16:09:53Z >Magister Scientiae - MSc The extreme conditions of Antarctic desert soils render this environment selective towards a diverse range of psychrotrophic microbial communities. Cracks and fissures in translucent quartz rocks permit an adequate amount of penetrating light, sufficient water and nutrients to support cryptic microbial development. Hypolithons colonizing the ventral surface of these quartz rocks have been classified into three types: cyanobacterial dominated (Type I),moss dominated (Type II) and lichenized (Type III) communities. Eukaryotic microbial communities were reported to represent only a minor fraction of Antarctic communities. In this study, culture independent techniques (DGGE, T-RFLP and clone library construction) were employed to determine the profile of the dominant eukaryotes, fungi and microalgae present in the three different hypolithic communities. The 18S rRNA gene (Euk for eukaryotes), internal transcribed spacer (ITS for fungi) and microalgal specific regions of the 18S rRNA gene, were the phylogenetic markers targeted for PCR amplification from hypolith metagenomic DNA. Results suggest that the three hypolith types are characterized by different eukaryotic, fungal and microalgal communities, as implied by nMDS analysis of the DGGE and T-RFLP profiles. Sequence analysis indicates close affiliation to members of Amoebozoa, Alveolata, Rhizaria (general eukaryote), Ascomycota (fungal) and Streptophyta (microalgal). Many of these clones may represent novel species. This study demonstrates that Dry Valley hypolithons harbour higher eukaryote diversity than previously recognised.Each hypolithon is colonized by specialized microbial communities with possible keystone species. The ecological role of the detected microorganisms in the hypolith environment is also theorized, and a trophic hierarchy postulated. Thesis Antarc* Antarctic University of the Western Cape: Electronic Thesis and Dissertation Library Antarctic Miers ENVELOPE(163.850,163.850,-78.100,-78.100) Miers Valley ENVELOPE(164.200,164.200,-78.100,-78.100) |
institution |
Open Polar |
collection |
University of the Western Cape: Electronic Thesis and Dissertation Library |
op_collection_id |
ftunivwesterncap |
language |
English |
topic |
Hypolith Antarctic Dry Valleys Microbial diversity DGGE T-RFLP Culture independent ITS 18S Microalgae |
spellingShingle |
Hypolith Antarctic Dry Valleys Microbial diversity DGGE T-RFLP Culture independent ITS 18S Microalgae Keriuscia Gokul, Jarishma Eukaryotic diversity of miers valley hypoliths |
topic_facet |
Hypolith Antarctic Dry Valleys Microbial diversity DGGE T-RFLP Culture independent ITS 18S Microalgae |
description |
>Magister Scientiae - MSc The extreme conditions of Antarctic desert soils render this environment selective towards a diverse range of psychrotrophic microbial communities. Cracks and fissures in translucent quartz rocks permit an adequate amount of penetrating light, sufficient water and nutrients to support cryptic microbial development. Hypolithons colonizing the ventral surface of these quartz rocks have been classified into three types: cyanobacterial dominated (Type I),moss dominated (Type II) and lichenized (Type III) communities. Eukaryotic microbial communities were reported to represent only a minor fraction of Antarctic communities. In this study, culture independent techniques (DGGE, T-RFLP and clone library construction) were employed to determine the profile of the dominant eukaryotes, fungi and microalgae present in the three different hypolithic communities. The 18S rRNA gene (Euk for eukaryotes), internal transcribed spacer (ITS for fungi) and microalgal specific regions of the 18S rRNA gene, were the phylogenetic markers targeted for PCR amplification from hypolith metagenomic DNA. Results suggest that the three hypolith types are characterized by different eukaryotic, fungal and microalgal communities, as implied by nMDS analysis of the DGGE and T-RFLP profiles. Sequence analysis indicates close affiliation to members of Amoebozoa, Alveolata, Rhizaria (general eukaryote), Ascomycota (fungal) and Streptophyta (microalgal). Many of these clones may represent novel species. This study demonstrates that Dry Valley hypolithons harbour higher eukaryote diversity than previously recognised.Each hypolithon is colonized by specialized microbial communities with possible keystone species. The ecological role of the detected microorganisms in the hypolith environment is also theorized, and a trophic hierarchy postulated. |
author2 |
Cowan, D. A. Tuffin, Marla Stomeo, F. |
format |
Thesis |
author |
Keriuscia Gokul, Jarishma |
author_facet |
Keriuscia Gokul, Jarishma |
author_sort |
Keriuscia Gokul, Jarishma |
title |
Eukaryotic diversity of miers valley hypoliths |
title_short |
Eukaryotic diversity of miers valley hypoliths |
title_full |
Eukaryotic diversity of miers valley hypoliths |
title_fullStr |
Eukaryotic diversity of miers valley hypoliths |
title_full_unstemmed |
Eukaryotic diversity of miers valley hypoliths |
title_sort |
eukaryotic diversity of miers valley hypoliths |
publisher |
University of the Western Cape |
publishDate |
2012 |
url |
http://hdl.handle.net/11394/4031 |
long_lat |
ENVELOPE(163.850,163.850,-78.100,-78.100) ENVELOPE(164.200,164.200,-78.100,-78.100) |
geographic |
Antarctic Miers Miers Valley |
geographic_facet |
Antarctic Miers Miers Valley |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
http://hdl.handle.net/11394/4031 |
op_rights |
University of the Western Cape |
_version_ |
1766272299941494784 |