Microbial Mat Communities along an Oxygen Gradient in a Perennially Ice-Covered Antarctic Lake
ABSTRACT Lake Fryxell is a perennially ice-covered lake in the McMurdo Dry Valleys, Antarctica, with a sharp oxycline in a water column that is density stabilized by a gradient in salt concentration. Dissolved oxygen falls from 20 mg liter −1 to undetectable over one vertical meter from 8.9- to 9.9-...
Published in: | Applied and Environmental Microbiology |
---|---|
Main Authors: | , , , , , , , , |
Other Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Society for Microbiology
2016
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1128/aem.02699-15 https://journals.asm.org/doi/pdf/10.1128/AEM.02699-15 |
id |
crasmicro:10.1128/aem.02699-15 |
---|---|
record_format |
openpolar |
spelling |
crasmicro:10.1128/aem.02699-15 2024-09-30T14:25:44+00:00 Microbial Mat Communities along an Oxygen Gradient in a Perennially Ice-Covered Antarctic Lake Jungblut, Anne D. Hawes, Ian Mackey, Tyler J. Krusor, Megan Doran, Peter T. Sumner, Dawn Y. Eisen, Jonathan A. Hillman, Colin Goroncy, Alexander K. Stams, A. J. NSF NASA 2016 http://dx.doi.org/10.1128/aem.02699-15 https://journals.asm.org/doi/pdf/10.1128/AEM.02699-15 en eng American Society for Microbiology https://journals.asm.org/non-commercial-tdm-license Applied and Environmental Microbiology volume 82, issue 2, page 620-630 ISSN 0099-2240 1098-5336 journal-article 2016 crasmicro https://doi.org/10.1128/aem.02699-15 2024-09-09T04:15:57Z ABSTRACT Lake Fryxell is a perennially ice-covered lake in the McMurdo Dry Valleys, Antarctica, with a sharp oxycline in a water column that is density stabilized by a gradient in salt concentration. Dissolved oxygen falls from 20 mg liter −1 to undetectable over one vertical meter from 8.9- to 9.9-m depth. We provide the first description of the benthic mat community that falls within this oxygen gradient on the sloping floor of the lake, using a combination of micro- and macroscopic morphological descriptions, pigment analysis, and 16S rRNA gene bacterial community analysis. Our work focused on three macroscopic mat morphologies that were associated with different parts of the oxygen gradient: (i) “cuspate pinnacles” in the upper hyperoxic zone, which displayed complex topography and were dominated by phycoerythrin-rich cyanobacteria attributable to the genus Leptolyngbya and a diverse but sparse assemblage of pennate diatoms; (ii) a less topographically complex “ridge-pit” mat located immediately above the oxic-anoxic transition containing Leptolyngbya and an increasing abundance of diatoms; and (iii) flat prostrate mats in the upper anoxic zone, dominated by a green cyanobacterium phylogenetically identified as Phormidium pseudopriestleyi and a single diatom, Diadesmis contenta . Zonation of bacteria was by lake depth and by depth into individual mats. Deeper mats had higher abundances of bacteriochlorophylls and anoxygenic phototrophs, including Chlorobi and Chloroflexi . This suggests that microbial communities form assemblages specific to niche-like locations. Mat morphologies, underpinned by cyanobacterial and diatom composition, are the result of local habitat conditions likely defined by irradiance and oxygen and sulfide concentrations. Article in Journal/Newspaper Antarc* Antarctic Antarctica McMurdo Dry Valleys ASM Journals (American Society for Microbiology) Antarctic Fryxell ENVELOPE(163.183,163.183,-77.617,-77.617) Lake Fryxell ENVELOPE(163.183,163.183,-77.617,-77.617) McMurdo Dry Valleys Applied and Environmental Microbiology 82 2 620 630 |
institution |
Open Polar |
collection |
ASM Journals (American Society for Microbiology) |
op_collection_id |
crasmicro |
language |
English |
description |
ABSTRACT Lake Fryxell is a perennially ice-covered lake in the McMurdo Dry Valleys, Antarctica, with a sharp oxycline in a water column that is density stabilized by a gradient in salt concentration. Dissolved oxygen falls from 20 mg liter −1 to undetectable over one vertical meter from 8.9- to 9.9-m depth. We provide the first description of the benthic mat community that falls within this oxygen gradient on the sloping floor of the lake, using a combination of micro- and macroscopic morphological descriptions, pigment analysis, and 16S rRNA gene bacterial community analysis. Our work focused on three macroscopic mat morphologies that were associated with different parts of the oxygen gradient: (i) “cuspate pinnacles” in the upper hyperoxic zone, which displayed complex topography and were dominated by phycoerythrin-rich cyanobacteria attributable to the genus Leptolyngbya and a diverse but sparse assemblage of pennate diatoms; (ii) a less topographically complex “ridge-pit” mat located immediately above the oxic-anoxic transition containing Leptolyngbya and an increasing abundance of diatoms; and (iii) flat prostrate mats in the upper anoxic zone, dominated by a green cyanobacterium phylogenetically identified as Phormidium pseudopriestleyi and a single diatom, Diadesmis contenta . Zonation of bacteria was by lake depth and by depth into individual mats. Deeper mats had higher abundances of bacteriochlorophylls and anoxygenic phototrophs, including Chlorobi and Chloroflexi . This suggests that microbial communities form assemblages specific to niche-like locations. Mat morphologies, underpinned by cyanobacterial and diatom composition, are the result of local habitat conditions likely defined by irradiance and oxygen and sulfide concentrations. |
author2 |
Stams, A. J. NSF NASA |
format |
Article in Journal/Newspaper |
author |
Jungblut, Anne D. Hawes, Ian Mackey, Tyler J. Krusor, Megan Doran, Peter T. Sumner, Dawn Y. Eisen, Jonathan A. Hillman, Colin Goroncy, Alexander K. |
spellingShingle |
Jungblut, Anne D. Hawes, Ian Mackey, Tyler J. Krusor, Megan Doran, Peter T. Sumner, Dawn Y. Eisen, Jonathan A. Hillman, Colin Goroncy, Alexander K. Microbial Mat Communities along an Oxygen Gradient in a Perennially Ice-Covered Antarctic Lake |
author_facet |
Jungblut, Anne D. Hawes, Ian Mackey, Tyler J. Krusor, Megan Doran, Peter T. Sumner, Dawn Y. Eisen, Jonathan A. Hillman, Colin Goroncy, Alexander K. |
author_sort |
Jungblut, Anne D. |
title |
Microbial Mat Communities along an Oxygen Gradient in a Perennially Ice-Covered Antarctic Lake |
title_short |
Microbial Mat Communities along an Oxygen Gradient in a Perennially Ice-Covered Antarctic Lake |
title_full |
Microbial Mat Communities along an Oxygen Gradient in a Perennially Ice-Covered Antarctic Lake |
title_fullStr |
Microbial Mat Communities along an Oxygen Gradient in a Perennially Ice-Covered Antarctic Lake |
title_full_unstemmed |
Microbial Mat Communities along an Oxygen Gradient in a Perennially Ice-Covered Antarctic Lake |
title_sort |
microbial mat communities along an oxygen gradient in a perennially ice-covered antarctic lake |
publisher |
American Society for Microbiology |
publishDate |
2016 |
url |
http://dx.doi.org/10.1128/aem.02699-15 https://journals.asm.org/doi/pdf/10.1128/AEM.02699-15 |
long_lat |
ENVELOPE(163.183,163.183,-77.617,-77.617) ENVELOPE(163.183,163.183,-77.617,-77.617) |
geographic |
Antarctic Fryxell Lake Fryxell McMurdo Dry Valleys |
geographic_facet |
Antarctic Fryxell Lake Fryxell McMurdo Dry Valleys |
genre |
Antarc* Antarctic Antarctica McMurdo Dry Valleys |
genre_facet |
Antarc* Antarctic Antarctica McMurdo Dry Valleys |
op_source |
Applied and Environmental Microbiology volume 82, issue 2, page 620-630 ISSN 0099-2240 1098-5336 |
op_rights |
https://journals.asm.org/non-commercial-tdm-license |
op_doi |
https://doi.org/10.1128/aem.02699-15 |
container_title |
Applied and Environmental Microbiology |
container_volume |
82 |
container_issue |
2 |
container_start_page |
620 |
op_container_end_page |
630 |
_version_ |
1811646299124006912 |