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dc.contributor.advisorCowan, D. A.
dc.contributor.advisorTuffin, Marla
dc.contributor.advisorStomeo, F.
dc.contributor.authorKeriuscia Gokul, Jarishma
dc.date.accessioned2015-03-24T08:16:36Z
dc.date.available2015-03-24T08:16:36Z
dc.date.issued2012
dc.identifier.urihttp://hdl.handle.net/11394/4031
dc.description>Magister Scientiae - MScen_US
dc.description.abstractThe 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.en_US
dc.language.isoenen_US
dc.publisherUniversity of the Western Capeen_US
dc.subjectHypolithen_US
dc.subjectAntarcticen_US
dc.subjectDry Valleysen_US
dc.subjectMicrobial diversityen_US
dc.subjectDGGEen_US
dc.subjectT-RFLPen_US
dc.subjectCulture independenten_US
dc.subjectITSen_US
dc.subject18Sen_US
dc.subjectMicroalgaeen_US
dc.titleEukaryotic diversity of miers valley hypolithsen_US
dc.typeThesisen_US
dc.rights.holderUniversity of the Western Capeen_US


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