Current Research Project
EAGER: Persist or perish: Records of microbial survival and long-term persistence from the West Antarctic Ice Sheet (NSF#2228257)
Ice cores from glaciers and ice sheets provide detailed, multiproxy archives of paleoenvironmental conditions, furthering our understanding of Earth’s climate. Microorganisms in the West Antarctic Ice Sheet are buried over glaciological time and form a stratigraphic record, with potential links to Southern Hemisphere climate. However, microbial cells that land on the ice sheet are subject to the stresses of changing habitat conditions due to burial and low- energy conditions associated with long-term isolation in an ice sheet. These post-depositional processes may lead to environmental filtering of cells over time and a loss of fidelity within the WD stratigraphic record of microbial cells. We know little about how and if microorganisms survive burial and remain viable over glacial-interglacial time periods within an ice sheet. Our analysis will identify the viable and preserved community of microorganisms and core genomic adaptation that permit cell viability. These genomes will be the first genomic data from the Antarctic Ice Sheet and inform whether post-deposition processes impact the interpretations of paleoenvironmental conditions from microbial cell data.
External Collaborator Projects
SALSA - Subglacial Antarctic Lakes Scientific Access
I participated in the SALSA project as an international collaborator to help with the sediment microbiology/biogeochemistry goals of the project. SALSA accessed Subglacial Lake Mercer in West Antarctica using the same clean, hot water drill as was used for Subglacial Lake Whillans. Once through the approximately 1100 m of overlying ice, we collected water and sediment samples with the goal of understanding how relict and contemporary processes sustain a microbial ecosystem.
https://salsa-antarctica.org/
https://salsa-antarctica.org/
Microbiology of the Tibetan Plateau Glaciers and Lakes
Along with my colleagues from Montana State University, I have been working with Younqin Liu and her Chinese collaborators to describe the microbiology found in the many unique lakes and glacier ecosystems of the Tibetan Plateau.
Peer-Reviewed Publications
*Co-first authorship; (#) Bachelors student advisee
34. Rosenheim, BE*, AB Michaud*, J Broda, A Gagnon, A Leventer, RA Venturelli, MO Patterson, TD Campbell, JE Dore, M Tranter, ML Skidmore. Sediment coring operations during clean access of Mercer Subglacial Lake, Antarctica. Limnology and Oceanography: Methods. (Accepted)
33. Michaud, AB, RO Masse (#), D Emerson. 2023. Iron cycling is prevalent in water-logged habitats of the Alaskan Arctic tundra, but sensitive to disturbance. FEMS Microbiology Ecology. doi: 10.1093/femsec/fiad013
32. Davis, C, RA Venturelli, AB Michaud, J Hawkings, AM Achberger, TJ Vick-Majors, BE Rosenheim, JE Dore, A Steigmeyer, ML Skidmore, J Barker, L Benning, MR Siegfried, JC Priscu, BC Christner. 2023. Biogeochemical and historical drivers of microbial community composition and structure in sediments from Mercer Subglacial Lake, West Antarctica. ISME Communications. 3:8 doi: https://doi.org/10.1038/s43705-023-00216-w
31. Beam*, JP, AB Michaud*, DT Johnston, PR Girguis, D Emerson. 2022. Impacts of bioturbation on iron biogeochemistry and microbial communities in a coastal marine sediment under varying degrees of hypoxia. Estuarine, Coastal, and Shelf Science. 276:108032. doi: https://doi.org/10.1016/j.ecss.2022.108032
30. Gustafson, CG, K Key, MR Siegfried, JP Winberry, HA Fricker, RA Venturelli, AB Michaud. 2022. A dynamic saline groundwater system mapped beneath an Antarctic ice stream. Science. 376:640-644. doi: https://doi.org/10.1126/science.abm3301
29. Michaud, AB and S Apollonio. Silicate and oxygen dynamics throughout the winter in an Arctic lake (Immerk Lake, Devon Island, Canada). Inland Waters. 12:418-426. doi: https://doi.org/10.1080/20442041.2022.2063623
28. Hudson, JM, AB Michaud, D Emerson, and Y-P Chin. (2022) High-resolution spatial distribution of redox-active species in Arctic porewaters. Environmental Science: Processes & Impacts. 24, 426-438. doi: 10.1039/D1EM00505G
27. Herbert, LC, AB Michaud, K Laufer-Meiser, CJM Hoppe, Q Zhu, RC Aller, BB Jørgensen, and LM Wehrmann. (2021) Seasonal carbon export drives changes in coupled Fe-S cycling dynamics in an Arctic fjord (Kongsfjorden, Svalbard). Journal of Marine Systems. 225:103465 doi: https://doi.org/10.1016/j.jmarsys.2021.103645
26. Herbert, L.C., Q. Zhu, A.B. Michaud, K. Kaufer, C.K. Jones, N. Riedinger, Z.S. Stooksbury, R.C. Aller, B.B. Jørgensen, L.M. Wehrmann. (2021) Benthic iron flux induced by climate-sensitive interplay between organic carbon availability and sedimentation rate in Arctic fjords. Limnology and Oceanography. 66: 3374-3392. doi: https://doi.org/10.1002/lno.11885
25. Priscu, J.C., J. Kalin, J. Winans, T. Campbell, M.R. Siegfried, M. Skidmore, J.E. Dore, A. Leventer, D.M. Harwood, D. Duling, R. Zook, J. Burnett, D. Gibson, E. Krula, A. Mironov, J. McManis, G. Roberts, B.E. Rosenheim, B.C. Christner, K. Kasic, H.A. Fricker, W.B. Lyons, J. Barker, M. Bowling, B. Collins, C. Davis, A. Gagnon, C. Gardner, C. Gustafson, O.-S. Kim, W. Li, A.B. Michaud, M.O. Patterson, M. Tranter, R. Venturelli, T. Vick-Majors, C. Elsworth, The SALSA Science Team. (2021) Scientific access into Mercer Subglacial Lake: scientific objectives, drilling operations and initial observations. Annals of Glaciology. 62:340-352. doi: https://doi.org/10.1017/aog.2021.10
24. Laufer-Meiser, K., A.B. Michaud, M. Maisch, J.M. Byrne, A. Kappler, M.O. Patterson, H. Røy, B.B. Jørgensen. (2021) Potentially bioavailable iron produced through benthic cycling in glaciated Arctic fjords of Svalbard. Nature Communications. 12:1349. doi: https://doi.org/10.1038/s41467-021-21558-w
23. Jørgensen, B.B., K. Laufer, A.B. Michaud, L.M. Wehrmann. (2021) Biogeochemistry and microbiology of high Arctic marine sediment ecosystems - case study Svalbard fjords. Limnology and Oceanography. 66:S273-292. doi: 10.1002/lno.11551
22. Michaud, A.B., T.J. Vick-Majors, A.M. Achberger, M.L. Skidmore, B.C. Christner, M. Tranter, J.C. Priscu. (2020) Environmentally clean access to Antarctic subglacial aquatic environments. Antarctic Science. 32:329-340. doi: 10.1017/S0954102020000231
**This article is open access courtesy of the Montana State University Library's Open Access Author Fund here
21. Vick-Majors, T.J., A.B. Michaud, M.L. Skidmore, C. Turetta, C. Barbante, B.C. Christner, J.E. Dore, K. Christianson, A.C. Mitchell, A. M. Achberger, J.A. Mikucki, J.C. Priscu. (2020) Bigeochemical connectivity between freshwater ecosystems beneath the West Antarctic Ice Sheet and sub-ice marine environment. Global Biogeochemical Cycles. 34:e2019GB006446. doi: 10.1029/2019GB006446
20. Michaud, A.B., K. Laufer, A. Findlay, A. Pellerin, G. Antler, A.V. Turchyn, H. Røy, L.M. Wehrmann, B.B. Jørgensen. (2020) Glacial influence on the iron and sulfur cycles in Arctic fjord sediments (Svalbard). Geochimica et Cosmochimica Acta. 280:423-440. doi: https://doi.org/10.1016/j.gca.2019.12.033
19. Herbert, L.C., N. Riedinger, A.B. Michaud, K. Laufer, H. Røy, B.B. Jørgensen, C. Heilbrun, R.C. Aller, J.K. Cochran, L.M. Wehrmann. (2020) Glacial controls on redox-sensitive trace element cycling in Arctic fjord sediments (Spitsbergen, Svalbard). Geochimica et Cosmochimica Acta. 271:33-60. doi: https://doi.org/10.1016/j.gca.2019.12.005
18. Laufer, K., A.B. Michaud, H. Røy, B.B. Jørgensen. (2020) Reactivity of iron minerals in the seabeds towards microbial reduction - a comparison of different extraction techniques. Geomicrobiology Journal. 37:170-189. doi: https://doi.org/10.1080/01490451.2019.1679291
17. Buongiorno, J., L.C. Herbert, L.M. Wehrmann, A.B. Michaud, K. Laufer, H. Røy, B.B. Jørgensen, A. Szynkiewicz, A. Faiia, K.M. Yeager, K. Schindler, K.G. Lloyd. (2019) Complex microbial communities drive iron and sulfur cycling in Arctic fjord sediments. Applied and Environmental Microbiology. 85:e00949-19. doi: https://doi.org/10.1128/AEM.00949-19
16. Santibáñez, P.A., A.B. Michaud, T.J. Vick-Majors, J. D’Andrilli, A. Chiuchiolo, K.P. Hand, J.C. Priscu. (2019) Differential incorporation of bacteria, organic matter, and inorganic ions into lake ice during ice formation. Journal of Geophysical Research: Biogeosciences. 124:585-600. doi: https://doi.org/10.1029/2018JG004825
34. Rosenheim, BE*, AB Michaud*, J Broda, A Gagnon, A Leventer, RA Venturelli, MO Patterson, TD Campbell, JE Dore, M Tranter, ML Skidmore. Sediment coring operations during clean access of Mercer Subglacial Lake, Antarctica. Limnology and Oceanography: Methods. (Accepted)
33. Michaud, AB, RO Masse (#), D Emerson. 2023. Iron cycling is prevalent in water-logged habitats of the Alaskan Arctic tundra, but sensitive to disturbance. FEMS Microbiology Ecology. doi: 10.1093/femsec/fiad013
32. Davis, C, RA Venturelli, AB Michaud, J Hawkings, AM Achberger, TJ Vick-Majors, BE Rosenheim, JE Dore, A Steigmeyer, ML Skidmore, J Barker, L Benning, MR Siegfried, JC Priscu, BC Christner. 2023. Biogeochemical and historical drivers of microbial community composition and structure in sediments from Mercer Subglacial Lake, West Antarctica. ISME Communications. 3:8 doi: https://doi.org/10.1038/s43705-023-00216-w
31. Beam*, JP, AB Michaud*, DT Johnston, PR Girguis, D Emerson. 2022. Impacts of bioturbation on iron biogeochemistry and microbial communities in a coastal marine sediment under varying degrees of hypoxia. Estuarine, Coastal, and Shelf Science. 276:108032. doi: https://doi.org/10.1016/j.ecss.2022.108032
30. Gustafson, CG, K Key, MR Siegfried, JP Winberry, HA Fricker, RA Venturelli, AB Michaud. 2022. A dynamic saline groundwater system mapped beneath an Antarctic ice stream. Science. 376:640-644. doi: https://doi.org/10.1126/science.abm3301
29. Michaud, AB and S Apollonio. Silicate and oxygen dynamics throughout the winter in an Arctic lake (Immerk Lake, Devon Island, Canada). Inland Waters. 12:418-426. doi: https://doi.org/10.1080/20442041.2022.2063623
28. Hudson, JM, AB Michaud, D Emerson, and Y-P Chin. (2022) High-resolution spatial distribution of redox-active species in Arctic porewaters. Environmental Science: Processes & Impacts. 24, 426-438. doi: 10.1039/D1EM00505G
27. Herbert, LC, AB Michaud, K Laufer-Meiser, CJM Hoppe, Q Zhu, RC Aller, BB Jørgensen, and LM Wehrmann. (2021) Seasonal carbon export drives changes in coupled Fe-S cycling dynamics in an Arctic fjord (Kongsfjorden, Svalbard). Journal of Marine Systems. 225:103465 doi: https://doi.org/10.1016/j.jmarsys.2021.103645
26. Herbert, L.C., Q. Zhu, A.B. Michaud, K. Kaufer, C.K. Jones, N. Riedinger, Z.S. Stooksbury, R.C. Aller, B.B. Jørgensen, L.M. Wehrmann. (2021) Benthic iron flux induced by climate-sensitive interplay between organic carbon availability and sedimentation rate in Arctic fjords. Limnology and Oceanography. 66: 3374-3392. doi: https://doi.org/10.1002/lno.11885
25. Priscu, J.C., J. Kalin, J. Winans, T. Campbell, M.R. Siegfried, M. Skidmore, J.E. Dore, A. Leventer, D.M. Harwood, D. Duling, R. Zook, J. Burnett, D. Gibson, E. Krula, A. Mironov, J. McManis, G. Roberts, B.E. Rosenheim, B.C. Christner, K. Kasic, H.A. Fricker, W.B. Lyons, J. Barker, M. Bowling, B. Collins, C. Davis, A. Gagnon, C. Gardner, C. Gustafson, O.-S. Kim, W. Li, A.B. Michaud, M.O. Patterson, M. Tranter, R. Venturelli, T. Vick-Majors, C. Elsworth, The SALSA Science Team. (2021) Scientific access into Mercer Subglacial Lake: scientific objectives, drilling operations and initial observations. Annals of Glaciology. 62:340-352. doi: https://doi.org/10.1017/aog.2021.10
24. Laufer-Meiser, K., A.B. Michaud, M. Maisch, J.M. Byrne, A. Kappler, M.O. Patterson, H. Røy, B.B. Jørgensen. (2021) Potentially bioavailable iron produced through benthic cycling in glaciated Arctic fjords of Svalbard. Nature Communications. 12:1349. doi: https://doi.org/10.1038/s41467-021-21558-w
23. Jørgensen, B.B., K. Laufer, A.B. Michaud, L.M. Wehrmann. (2021) Biogeochemistry and microbiology of high Arctic marine sediment ecosystems - case study Svalbard fjords. Limnology and Oceanography. 66:S273-292. doi: 10.1002/lno.11551
22. Michaud, A.B., T.J. Vick-Majors, A.M. Achberger, M.L. Skidmore, B.C. Christner, M. Tranter, J.C. Priscu. (2020) Environmentally clean access to Antarctic subglacial aquatic environments. Antarctic Science. 32:329-340. doi: 10.1017/S0954102020000231
**This article is open access courtesy of the Montana State University Library's Open Access Author Fund here
21. Vick-Majors, T.J., A.B. Michaud, M.L. Skidmore, C. Turetta, C. Barbante, B.C. Christner, J.E. Dore, K. Christianson, A.C. Mitchell, A. M. Achberger, J.A. Mikucki, J.C. Priscu. (2020) Bigeochemical connectivity between freshwater ecosystems beneath the West Antarctic Ice Sheet and sub-ice marine environment. Global Biogeochemical Cycles. 34:e2019GB006446. doi: 10.1029/2019GB006446
20. Michaud, A.B., K. Laufer, A. Findlay, A. Pellerin, G. Antler, A.V. Turchyn, H. Røy, L.M. Wehrmann, B.B. Jørgensen. (2020) Glacial influence on the iron and sulfur cycles in Arctic fjord sediments (Svalbard). Geochimica et Cosmochimica Acta. 280:423-440. doi: https://doi.org/10.1016/j.gca.2019.12.033
19. Herbert, L.C., N. Riedinger, A.B. Michaud, K. Laufer, H. Røy, B.B. Jørgensen, C. Heilbrun, R.C. Aller, J.K. Cochran, L.M. Wehrmann. (2020) Glacial controls on redox-sensitive trace element cycling in Arctic fjord sediments (Spitsbergen, Svalbard). Geochimica et Cosmochimica Acta. 271:33-60. doi: https://doi.org/10.1016/j.gca.2019.12.005
18. Laufer, K., A.B. Michaud, H. Røy, B.B. Jørgensen. (2020) Reactivity of iron minerals in the seabeds towards microbial reduction - a comparison of different extraction techniques. Geomicrobiology Journal. 37:170-189. doi: https://doi.org/10.1080/01490451.2019.1679291
17. Buongiorno, J., L.C. Herbert, L.M. Wehrmann, A.B. Michaud, K. Laufer, H. Røy, B.B. Jørgensen, A. Szynkiewicz, A. Faiia, K.M. Yeager, K. Schindler, K.G. Lloyd. (2019) Complex microbial communities drive iron and sulfur cycling in Arctic fjord sediments. Applied and Environmental Microbiology. 85:e00949-19. doi: https://doi.org/10.1128/AEM.00949-19
16. Santibáñez, P.A., A.B. Michaud, T.J. Vick-Majors, J. D’Andrilli, A. Chiuchiolo, K.P. Hand, J.C. Priscu. (2019) Differential incorporation of bacteria, organic matter, and inorganic ions into lake ice during ice formation. Journal of Geophysical Research: Biogeosciences. 124:585-600. doi: https://doi.org/10.1029/2018JG004825
Cover: In Santibanez et al. (https://doi.org/10.1029/2018JG004825), image taken in January 2019 shows accretion ice that formed on the bottom of the West Antarctic Ice Sheet where it flows over Subglacial Lake Mercer, Antarctica. The ice-lake water interface is located 1092 m beneath the surface of the ice sheet. The clear accretion ice is located in the upper right section of the image and the lake water in the lower left section. The scale is approximately 20 cm across. The image was taken with the ROV Deep Scini by Bob Zook and John Winans of the SALSA Science Team with support from the National Science Foundation.
15. Liu, Y., J.C. Priscu, T. Yao, T.J. Vick-Majors, A.B. Michaud, L. Sheng. (2019) Culturable bacteria isolated from seven high altitude Tibetan ice cores. Journal of Glaciology. 65:29-38. doi: https://doi.org/10.1017/jog.2018.86
14. Michaud, A.B., J.E. Dore, A.M. Achberger, B.C. Christner, A.C. Mitchell, M.L. Skidmore, T.J. Vick-Majors, J.C. Priscu. 2017. Microbial oxidation as a methane sink beneath the West Antarctic Ice Sheet. Nature Geoscience. 10:582-586. doi: https://doi.org/10.1038/ngeo2992
**News and views in Nature Reviews Chemistry: https://doi.org/10.1038/s41570-017-0070
13. Vick-Majors, T.J., A.C. Mitchell, A.M. Achberger, B.C. Christner, J.E. Dore, A.B. Michaud, J.A. Mikucki, A.M. Purcell, M.L. Skidmore, J.C. Priscu, and The WISSARD Science Team. 2016. Physiological Ecology of Microorganisms in Subglacial Lake Whillans. Frontiers in Microbiology. 7:1705. doi: 10.3389/fmicb.2016.01705
12. Achberger, A.M., B.C. Christner, A.B. Michaud, J.C. Priscu, M.L. Skidmore, T.J. Vick-Majors and the WISSARD Science Team. 2016. Microbial Community Structure of Subglacial Lake Whillans, West Antarctica. Frontiers in Microbiology. 7:1-13. doi: 10.3389/fmicb.2016.01457
11. Michaud, A.B., M.L. Skidmore, A.C. Mitchell, T.J. Vick-Majors, C. Barbante, C. Turetta, W. vanGelder, J.C. Priscu. 2016. Solute sources and geochemical processes in Subglacial Lake Whillans, West Antarctica. Geology. 44:347. doi: https://doi.org/10.1130/G37639.1
**This article is open access courtesy of the Montana State University Library's Open Access Author Fund here
**Geology Research Focus on this paper can be found here
10. Liu, Y., J.C. Priscu, T. Yao, T.J. Vick-Majors, B. Xu, N. Jiao, P. Santibáñez, S. Huang, N. Wang, M. Greenwood, A.B. Michaud, S. Kang, J. Wang, Y. Yang. Bacterial responses to environmental change in the Tibetan Plateau over the past half century. Environmental Microbiology. 18:1930-1941. doi: https://doi.org/10.1111/1462-2920.13115
9. Vick-Majors, T.J., A.M. Achberger, P. Santibáñez, J.E. Dore, T. Hodson, A.B. Michaud, B.C. Christner, J. Mikucki, M.L. Skidmore, R. Powell, W.P. Adkins, C. Barbante, A. Mitchell, R. Scherer, J.C. Priscu. 2015. Microbial diversity and biogeochemistry of the marine cavity beneath the McMurdo Ice Shelf, Antarctica. Limnology and Oceanography. 61:572-586. doi: https://doi.org/10.1002/lno.10234
8. Lever, M.A., A. Torti, P. Eickenbusch, A.B. Michaud, T. Šantl-Temkiv, B.B. Jørgensen. 2015. A modular method for the extraction of DNA and RNA, and the separation of DNA pools from diverse environmental sample types. Frontiers in Microbiology, 6:1. doi: https://doi.org/10.3389/fmicb.2015.00476
7. Matheus-Carnevali, P., M. Rohrssen, M.R. Williams, A.B. Michaud, H. Adams, D. Berisford, G.D. Love, J.C. Priscu, K.P. Hand, A.E. Murray. 2014. Methane sources in Arctic thermokarst lake sediments on the North Slope of Alaska. Geobiology, 13:181. doi: https://doi.org/10.1111/gbi.12124
6. Purcel, A.M., J.A. Mikucki, A.M. Achberger, I.A. Alekhina, C. Barbante, B.C. Christner, D. Ghosh, A.B. Michaud, A.C. Mitchell, R. Scherer, J.C. Priscu, M.L. Skidmore, T.J. Vick-Majors and the WISSARD Science Team. Microbial sulfur transformations in sediments from Subglacial Lake Whillans. Frontiers in Microbiology, 5:1. doi: https://doi.org/10.3389/fmicb.2014.00594.
5. Michaud A.B., J.E. Dore, D. Leslie, W.B. Lyons, D.C. Sands, J.C. Priscu. 2014. Biological ice nucleation initiates hailstone formation. Journal of Geophysical Research: Atmospheres, 119:12,186-12,197. doi: https://doi.org/10.1002/2014JD022004
14. Michaud, A.B., J.E. Dore, A.M. Achberger, B.C. Christner, A.C. Mitchell, M.L. Skidmore, T.J. Vick-Majors, J.C. Priscu. 2017. Microbial oxidation as a methane sink beneath the West Antarctic Ice Sheet. Nature Geoscience. 10:582-586. doi: https://doi.org/10.1038/ngeo2992
**News and views in Nature Reviews Chemistry: https://doi.org/10.1038/s41570-017-0070
13. Vick-Majors, T.J., A.C. Mitchell, A.M. Achberger, B.C. Christner, J.E. Dore, A.B. Michaud, J.A. Mikucki, A.M. Purcell, M.L. Skidmore, J.C. Priscu, and The WISSARD Science Team. 2016. Physiological Ecology of Microorganisms in Subglacial Lake Whillans. Frontiers in Microbiology. 7:1705. doi: 10.3389/fmicb.2016.01705
12. Achberger, A.M., B.C. Christner, A.B. Michaud, J.C. Priscu, M.L. Skidmore, T.J. Vick-Majors and the WISSARD Science Team. 2016. Microbial Community Structure of Subglacial Lake Whillans, West Antarctica. Frontiers in Microbiology. 7:1-13. doi: 10.3389/fmicb.2016.01457
11. Michaud, A.B., M.L. Skidmore, A.C. Mitchell, T.J. Vick-Majors, C. Barbante, C. Turetta, W. vanGelder, J.C. Priscu. 2016. Solute sources and geochemical processes in Subglacial Lake Whillans, West Antarctica. Geology. 44:347. doi: https://doi.org/10.1130/G37639.1
**This article is open access courtesy of the Montana State University Library's Open Access Author Fund here
**Geology Research Focus on this paper can be found here
10. Liu, Y., J.C. Priscu, T. Yao, T.J. Vick-Majors, B. Xu, N. Jiao, P. Santibáñez, S. Huang, N. Wang, M. Greenwood, A.B. Michaud, S. Kang, J. Wang, Y. Yang. Bacterial responses to environmental change in the Tibetan Plateau over the past half century. Environmental Microbiology. 18:1930-1941. doi: https://doi.org/10.1111/1462-2920.13115
9. Vick-Majors, T.J., A.M. Achberger, P. Santibáñez, J.E. Dore, T. Hodson, A.B. Michaud, B.C. Christner, J. Mikucki, M.L. Skidmore, R. Powell, W.P. Adkins, C. Barbante, A. Mitchell, R. Scherer, J.C. Priscu. 2015. Microbial diversity and biogeochemistry of the marine cavity beneath the McMurdo Ice Shelf, Antarctica. Limnology and Oceanography. 61:572-586. doi: https://doi.org/10.1002/lno.10234
8. Lever, M.A., A. Torti, P. Eickenbusch, A.B. Michaud, T. Šantl-Temkiv, B.B. Jørgensen. 2015. A modular method for the extraction of DNA and RNA, and the separation of DNA pools from diverse environmental sample types. Frontiers in Microbiology, 6:1. doi: https://doi.org/10.3389/fmicb.2015.00476
7. Matheus-Carnevali, P., M. Rohrssen, M.R. Williams, A.B. Michaud, H. Adams, D. Berisford, G.D. Love, J.C. Priscu, K.P. Hand, A.E. Murray. 2014. Methane sources in Arctic thermokarst lake sediments on the North Slope of Alaska. Geobiology, 13:181. doi: https://doi.org/10.1111/gbi.12124
6. Purcel, A.M., J.A. Mikucki, A.M. Achberger, I.A. Alekhina, C. Barbante, B.C. Christner, D. Ghosh, A.B. Michaud, A.C. Mitchell, R. Scherer, J.C. Priscu, M.L. Skidmore, T.J. Vick-Majors and the WISSARD Science Team. Microbial sulfur transformations in sediments from Subglacial Lake Whillans. Frontiers in Microbiology, 5:1. doi: https://doi.org/10.3389/fmicb.2014.00594.
5. Michaud A.B., J.E. Dore, D. Leslie, W.B. Lyons, D.C. Sands, J.C. Priscu. 2014. Biological ice nucleation initiates hailstone formation. Journal of Geophysical Research: Atmospheres, 119:12,186-12,197. doi: https://doi.org/10.1002/2014JD022004
4. Christner, B.C., J.C. Priscu, A.M. Achberger, C. Barbante, A.B. Michaud, J.A. Mikucki, A.C. Mitchell, M.L. Skidmore, T.J. Vick-Majors and the WISSARD Science Team. 2014. Subglacial Lake Whillans: A microbial ecosystem beneath the West Antarctic Ice Sheet. Nature, 512:310. doi: https://doi.org/10.1038/nature13667
3. Liu, Y., T. Yao, J.C. Priscu, T.J. Vick-Majors, A.B. Michaud, N. Jiao, J. Hou, L. Tian, A. Hu, Z-Q. Chen. 2014. A comparison of pelagic, littoral, and riverine bacterial assemblages in Lake Bangongco, Tibetan Plateau. FEMS Microbiology Ecology, 89: 211. doi: https://doi.org/10.1111/1574-6941.12278
2. Priscu, J.C., A.M. Achberger, J.E. Cahoon, B.C. Christner, R.L. Edwards, W.L. Jones, A.B. Michaud, M.R. Siegfried, M.L. Skidmore, R.H. Spigel, G.W. Switzer, S. Tulaczyk, T.J. Vick-Majors. 2013. A microbiologically clean strategy for access to the Whillans Ice Stream subglacial environment. Antarctic Science, 25:637. doi: https://doi.org/10.1017/S0954102013000035
1. Michaud A.B., M. Sabacka, J.C. Priscu. 2012. Cyanobacterial diversity across landscape units in a polar desert: Taylor Valley, Antarctica. FEMS Microbiology Ecology, 82:268. doi: https://doi.org/10.1111/j.1574-6941.2012.01297.x
3. Liu, Y., T. Yao, J.C. Priscu, T.J. Vick-Majors, A.B. Michaud, N. Jiao, J. Hou, L. Tian, A. Hu, Z-Q. Chen. 2014. A comparison of pelagic, littoral, and riverine bacterial assemblages in Lake Bangongco, Tibetan Plateau. FEMS Microbiology Ecology, 89: 211. doi: https://doi.org/10.1111/1574-6941.12278
2. Priscu, J.C., A.M. Achberger, J.E. Cahoon, B.C. Christner, R.L. Edwards, W.L. Jones, A.B. Michaud, M.R. Siegfried, M.L. Skidmore, R.H. Spigel, G.W. Switzer, S. Tulaczyk, T.J. Vick-Majors. 2013. A microbiologically clean strategy for access to the Whillans Ice Stream subglacial environment. Antarctic Science, 25:637. doi: https://doi.org/10.1017/S0954102013000035
1. Michaud A.B., M. Sabacka, J.C. Priscu. 2012. Cyanobacterial diversity across landscape units in a polar desert: Taylor Valley, Antarctica. FEMS Microbiology Ecology, 82:268. doi: https://doi.org/10.1111/j.1574-6941.2012.01297.x
FEMS Microbiology Ecology cover image showing lake ice structures from Lake Fryxell in Taylor Valley Antarctica. The lake ice is one habitat for cyanobacteria investigated in Michaud et al., 2012 of this issue.
Non-author contributions:
For field work planning/assistance, contributing ideas/discussion, and/or editing:
10. Sipes et al., 2022. Permafrost Active Layer Microbes From Ny Ålesund, Svalbard (79°N) Show Autotrophic and Heterotrophic Metabolisms With Diverse Carbon-Degrading Enzymes. Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2021.757812
9. Flieder et al., 2021. Novel taxa of Acidobacteriota implicated in seafloor sulfur cycling. The ISME Journal. https://doi.org/10.1038/s41396-021-00992-0
8. Zinke et al., 2019. Microbial organic matter degradation potential in Baltic Sea sediments is influenced by depositional conditions and in situ geochemistry. Applied and Environmental Microbiology. https://doi.org/10.1128/AEM.02164-18
7. Tesson and Šantl-Temkiv. 2018. Ice Nucleation Activity and Aeolian Dispersal Success in Airborne and Aquatic Microalgae. Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2018.02681
6. Antler et al., 2018. The sulfur cycle below the sulfate-methane transition zone. GCA. https://www.sciencedirect.com/science/article/pii/S0016703718304137
5. Antler and Pellerin. 2018. A critical look at the combined use of sulfur and oxygen isotopes to study microbial metabolisms in methane-rich environments. Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2018.00519
4. Beulig et al., 2018. Control on rate and pathway of anaerobic organic carbon degradation in the seabed. PNAS. https://doi.org/10.1073/pnas.1715789115
3. Dial et al., 2018. What color should glacier algae be? An ecological role for red carbon in the cryosphere. FEMS Microbiology Ecology. https://doi.org/10.1093/femsec/fiy007
2. Donnelly, 2018. Piscide impact extends beyond targets and toxicity. Restoration Ecology. https://doi.org/10.1111/rec.12674
1. Kaiser et al., 2018. Landscape analysis of soil methane flux across complex terrain. Biogeosciences. https://doi.org/10.5194/bg-15-3143-2018
10. Sipes et al., 2022. Permafrost Active Layer Microbes From Ny Ålesund, Svalbard (79°N) Show Autotrophic and Heterotrophic Metabolisms With Diverse Carbon-Degrading Enzymes. Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2021.757812
9. Flieder et al., 2021. Novel taxa of Acidobacteriota implicated in seafloor sulfur cycling. The ISME Journal. https://doi.org/10.1038/s41396-021-00992-0
8. Zinke et al., 2019. Microbial organic matter degradation potential in Baltic Sea sediments is influenced by depositional conditions and in situ geochemistry. Applied and Environmental Microbiology. https://doi.org/10.1128/AEM.02164-18
7. Tesson and Šantl-Temkiv. 2018. Ice Nucleation Activity and Aeolian Dispersal Success in Airborne and Aquatic Microalgae. Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2018.02681
6. Antler et al., 2018. The sulfur cycle below the sulfate-methane transition zone. GCA. https://www.sciencedirect.com/science/article/pii/S0016703718304137
5. Antler and Pellerin. 2018. A critical look at the combined use of sulfur and oxygen isotopes to study microbial metabolisms in methane-rich environments. Frontiers in Microbiology. https://doi.org/10.3389/fmicb.2018.00519
4. Beulig et al., 2018. Control on rate and pathway of anaerobic organic carbon degradation in the seabed. PNAS. https://doi.org/10.1073/pnas.1715789115
3. Dial et al., 2018. What color should glacier algae be? An ecological role for red carbon in the cryosphere. FEMS Microbiology Ecology. https://doi.org/10.1093/femsec/fiy007
2. Donnelly, 2018. Piscide impact extends beyond targets and toxicity. Restoration Ecology. https://doi.org/10.1111/rec.12674
1. Kaiser et al., 2018. Landscape analysis of soil methane flux across complex terrain. Biogeosciences. https://doi.org/10.5194/bg-15-3143-2018
Peer-Reviewed Book Chapters
2. Vick-Majors, T.J., A.M. Achberger, A.B. Michaud, J.C. Priscu. Metabolic and taxonomic diversity in Antarctic subglacial environments. in Life in Extreme Environments: Insights in Biological Capability. (ed. G diPrisco, HGM Edwards, J Elster, AHL Huiskes) Cabridge University Press. (2020)
1. Achberger, A.M., A.B. Michaud, T.J. Vick-Majors, B.C. Christner, M.L. Skidmore, J.C. Priscu, and M. Tranter. 2017. Microbiology of Subglacial Environments. in Psychrophiles: From Biodiversity to Biotechnology. (Ed. R. Margesin) Springer.
**Chapter 5, Microbiology of Subglacial Environments is almost fully available on Google Books free preview.
1. Achberger, A.M., A.B. Michaud, T.J. Vick-Majors, B.C. Christner, M.L. Skidmore, J.C. Priscu, and M. Tranter. 2017. Microbiology of Subglacial Environments. in Psychrophiles: From Biodiversity to Biotechnology. (Ed. R. Margesin) Springer.
**Chapter 5, Microbiology of Subglacial Environments is almost fully available on Google Books free preview.
Non Peer-Reviewed Publications
1. Vick-Majors, T.J., M. Patterson, B. Schmidt, K. Makinson, T. Hewagama, J. Mikucki, D. Harwood, D. Winebrenner, M.R. Siegfried, A.B. Michaud, S. Tulaczyk. 2019. White Paper: Subglacial Access Working Group: Access Drilling Priorities in the Ross Ice Shelf Region. Ice Drilling Program Subglacial Access Working Group Science Planning Workshop, March 29-30, 2019, Herndon, Virginia, USA. https://icedrill.org/sites/default/files/Ross_Ice_Shelf_white_paper_final.pdf
Past Research Projects
Postdoctoral Research at Bigelow Laboratory for Ocean Sciences
\Permafrost contains massive amounts of carbon. The fate of this carbon is dependent on the activity of iron-reducing bacteria or methanogens that breakdown the carbon to either carbon dioxide or methane, respectively. The activity of iron-reducing microorganisms is dependent on a supply of thermodynamically favorable Fe(III)-oxides to be used as a terminal electron acceptor. One way these Fe-reducing bacteria may be supplied favorable electron acceptors is through the production of biological iron oxides by Fe-oxidizing bacteria. Fe-oxidizing bacteria produce conspicuous reddish-orange mats, as seen in the photo to the left, and are abundant in the Alaskan Arctic (so are mosquitoes...). I want to know if these biological Fe(III)-oxides provide a competitive advantage to Fe-reducing bacteria for carbon mineralization over methanogens.
I will use field-site monitoring, microcosm experiments, and genomics/metagenomics to determine the impact of biological Fe(III)-oxides on carbon mineralization in the Alaskan tundra. Results from this research have been published in FEMS Microbiology Ecology. |
Postdoc Research at Aarhus University
Arctic fjord sediment biogeochemical cycles
Kongsvegen calving front at the head of Kongsfjord, Spitsbergen, Svalbard. The strong influence of red, iron-rich sediment emanating from subglacial hydrologic component of Kongsvegen into Kongsfjord can be seen from this photo taken while flying into Ny-Aalesund, Svalbard. This iron-dominated sedimentation (see the photo section in the Field Work page for a close up of the sediment collected during sediment coring) may have a strong impact on the microbial activity and transport of iron to the marine shelf environment.
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In the Arctic, much of the subglacial discharge from glaciated catchments passes through fjords before release to the continental shelf regions. The supply of Fe and Mn from a glacier, through the fjord and to the marine shelf environment is dependent on the microbial rates and reactions that catalyze metal transformations in the fjord sediment. Fjords are more than a link between glaciers and the open ocean; they function as a biogochemically active interface between terrestrial subglacial processes and the marine environment. Thus, Arctic fjords are significant in the processing of important elements, such as Fe and Mn.
Microorganisms are important drivers of biogeochemical cycles (i.e., Fe, Mn, S) in fjord sediments, but current and future large-scale glacial controls on the rates of microbial biogeochemical cycling are uncertain. Given the paucity of data linking microbial rates of Fe, Mn, and S cycles with the active microbial populations and the significance of these biogeochemical cycles within changing Arctic fjords, my postdoctoral research will contribute to answering the question: How does current glacial activity and future glacial retreat impact the rate and composition of microbial communities contributing to metal export from fjord sediments? The Western Svalbard fjords represent a natural laboratory to address open questions concerning the role of microbial biogeochemical cycling in permanently cold marine sediments. These fjords have different sedimentation regimes, glacial activities, and bedrock types which allows for the impact of microbial metal cycling on the export of Fe and Mn to the shelf environment to be investigated. Results from this work has been published in the journals: Nature Communications, Limnology and Oceanography, Geochimica et Cosmochimica Acta, Geomicrobiology Journal, Applied and Environmental Microbiology, Journal of Marine Systems. |
PhD Research at Montana State University
Whillans Ice Stream Subglacial Access Research Drilling (WISSARD): Geomicrobiology of Subglacial Lake Whillans Sediments
The Antarctic subglacial lakes inventory has increased over the past forty years to include more than 350 identified subglacial lakes. It is now known that the water beneath the ice sheet moves between lakes, invoking an active sub-ice sheet drainage network. Many of these drainage networks in West Antarctica pass through thick glacial till layers before draining to the Southern Ocean. The vast area and depth of these saturated, subglacial sediments led to the title of world’s largest wetland. In one particular subglacial lake, Subglacial Lake Whillans (SLW), life has been documented in the water column and sediments; however, the microbial mediated biogeochemical cycles occurring in the subglacial saturated sediment are not well understood.
My research focuses on the microbial activity in the sediments of SLW and how their activity alters the porewater geochemistry and, ultimately, the geochemistry of SLW. I seek to quantify the microbial processes and the role of the overlying Antarctic Ice Sheet in regulating these microbially mediated biogeochemical cycles. Results from this work has been published in the journals: Nature, Nature Geoscience, Geology and Frontiers in Microbiology. |
Biological ice nucleation of hailstones
Hail has been a long-time nuisance to human agriculture and economy. The negative effects of hail have stimulated much research into the formation and prevention of hailstorms. I became interested in hailstones after a large storm pummeled Bozeman, MT in June 2010. My questions surrounding what nucleates hailstone embryos, the initial growth phase of a hailstone, was stimulated by recent studies documenting the role of biological ice nucleation in rain and snow. Hail is built in stages. The first stage is the embryo. The embryo is usually a frozen drop of water or agglomeration of ice crystals. These embryos form in a low altitude, warm cloud, ahead of the main anvil-looking thunderstorm cloud that is symbolic of hail and strong thunderstorms. These embryos freeze and then swept into the warm updraft, which begins the growth phase. The embryo now collects supercooled water droplets as it rises in the cloud. It falls and rises again gaining layers and mass. Once the mass of the hailstone overcomes the strength of the warm air updraft, it falls to the ground. These layers are a record or profile of the hailstones life history. We can peel away the layers to access the embryo and ask pointed questions regarding what was present when the embryo was nucleated. We found that biological ice nuclei were present in the embryos and stable isotopes of water corroborated our freezing experiments. These results support the findings from many physical studies of hailstones in the 1970’s and 1980’s.
This work has been published in the Journal of Geophysical Research: Atmospheres. |
Distribution of Cyanobacteria in the McMurdo Dry Valleys Region, Antarctica
The McMurdo Dry Valleys region is the most extreme polar desert on Earth. The ability of microorganisms to live in this harsh habitat is their ability to cope with dessication, high solar irradiance, no solar irradiance, and extreme cold. Cyanobacteria are one of the most successful organisms in this polar desert. Their growth during the short austral summers provides reduced carbon compounds to heterotrophic organisms. Cyanobacteria are the “Giant Sequoias” of the McMurdo Dry Valleys, if you will. I was interested in their distribution and taxonomy throughout Taylor Valley. Using two different molecular markers, I showed that there is a net transport of microorganisms down-valley, towards the sea. Also, as you move towards the sea, the diversity of cyanobacteria present increases. We hypothesized this was due to the high-energy fohn wonds that are characteristic of the Dry Valleys region. These strong winds redistribute sediment and also microorganisms, influencing their distribution and diversity.
This work has been published in FEMS Microbiology Ecology. |