Understanding microalgal composition and contributions in Antarctic glacial meltwater through rbcL sequencing
Microbial mats are found globally in dynamic aquatic environments. Visually different morphotypes (orange-red and black-green) also show different rates of nitrogen fixation and biogeochemical activity. Glacial meltwater communities in the McMurdo Dry Valleys (MDV) of Antarctica present unique oppor...
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San Francisco State University
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ftcalifstateuniv:oai:scholarworks:qn59q5551 2024-09-30T14:26:41+00:00 Understanding microalgal composition and contributions in Antarctic glacial meltwater through rbcL sequencing Kathryn Megan Barretto Edward J. Carpenter Jose de la Torre Jonathon Stillman 2016 http://hdl.handle.net/10211.3/181251 English eng San Francisco State University Science & Engineering Biology: Concentration in Integrative Biology http://hdl.handle.net/10211.3/181251 Copyright by Kathryn Megan Barretto, 2016 AS36 2016 BIOL .B37 Masters Thesis 2016 ftcalifstateuniv 2024-09-10T17:06:15Z Microbial mats are found globally in dynamic aquatic environments. Visually different morphotypes (orange-red and black-green) also show different rates of nitrogen fixation and biogeochemical activity. Glacial meltwater communities in the McMurdo Dry Valleys (MDV) of Antarctica present unique opportunities to study microbial mats, due to limited grazing effects and their sensitivity to climate change. Microscopy has yielded a poor understanding of species composition and diversity. I sought to address this limited understanding through deep sequencing of photosynthetic genes such as cbbL, and the 16S rRNA V4 hypervariable region. A total of 15 transects from five valleys were used, with samples representing stream-associated (submerged) or transiently wetted (hyporheic) transect points. While stream position is a clear driver of mat morphotype, morphotype was not associated with microbial community composition. Microbial mat communities exhibit temporal shifts in relative abundance, but not diversity of microorganisms present. We propose that unique mat morphotypes are not distinct communities, but rather a continuum of the same overall community ranging from submerged to hyporheic habitats. As such, microalgal mats have the potential for morphotypic and biogeochemical functional plasticity with changing hydrogeological conditions. Master Thesis Antarc* Antarctic Antarctica McMurdo Dry Valleys Scholarworks from California State University Antarctic McMurdo Dry Valleys |
institution |
Open Polar |
collection |
Scholarworks from California State University |
op_collection_id |
ftcalifstateuniv |
language |
English |
description |
Microbial mats are found globally in dynamic aquatic environments. Visually different morphotypes (orange-red and black-green) also show different rates of nitrogen fixation and biogeochemical activity. Glacial meltwater communities in the McMurdo Dry Valleys (MDV) of Antarctica present unique opportunities to study microbial mats, due to limited grazing effects and their sensitivity to climate change. Microscopy has yielded a poor understanding of species composition and diversity. I sought to address this limited understanding through deep sequencing of photosynthetic genes such as cbbL, and the 16S rRNA V4 hypervariable region. A total of 15 transects from five valleys were used, with samples representing stream-associated (submerged) or transiently wetted (hyporheic) transect points. While stream position is a clear driver of mat morphotype, morphotype was not associated with microbial community composition. Microbial mat communities exhibit temporal shifts in relative abundance, but not diversity of microorganisms present. We propose that unique mat morphotypes are not distinct communities, but rather a continuum of the same overall community ranging from submerged to hyporheic habitats. As such, microalgal mats have the potential for morphotypic and biogeochemical functional plasticity with changing hydrogeological conditions. |
author2 |
Edward J. Carpenter Jose de la Torre Jonathon Stillman |
format |
Master Thesis |
author |
Kathryn Megan Barretto |
spellingShingle |
Kathryn Megan Barretto Understanding microalgal composition and contributions in Antarctic glacial meltwater through rbcL sequencing |
author_facet |
Kathryn Megan Barretto |
author_sort |
Kathryn Megan Barretto |
title |
Understanding microalgal composition and contributions in Antarctic glacial meltwater through rbcL sequencing |
title_short |
Understanding microalgal composition and contributions in Antarctic glacial meltwater through rbcL sequencing |
title_full |
Understanding microalgal composition and contributions in Antarctic glacial meltwater through rbcL sequencing |
title_fullStr |
Understanding microalgal composition and contributions in Antarctic glacial meltwater through rbcL sequencing |
title_full_unstemmed |
Understanding microalgal composition and contributions in Antarctic glacial meltwater through rbcL sequencing |
title_sort |
understanding microalgal composition and contributions in antarctic glacial meltwater through rbcl sequencing |
publisher |
San Francisco State University |
publishDate |
2016 |
url |
http://hdl.handle.net/10211.3/181251 |
geographic |
Antarctic McMurdo Dry Valleys |
geographic_facet |
Antarctic McMurdo Dry Valleys |
genre |
Antarc* Antarctic Antarctica McMurdo Dry Valleys |
genre_facet |
Antarc* Antarctic Antarctica McMurdo Dry Valleys |
op_source |
AS36 2016 BIOL .B37 |
op_relation |
http://hdl.handle.net/10211.3/181251 |
op_rights |
Copyright by Kathryn Megan Barretto, 2016 |
_version_ |
1811632814326546432 |