John A. Baross (born August 27, 1940) is an American marine microbiologist and professor of oceanography and astrobiology at the University of Washington who has made significant discoveries in the field of microbial ecology of hydrothermal vents and the physiology of thermophilic bacteria and archaea.[1]

John A. Baross
BornAugust 27, 1940
Alma materUniversity of Washington, San Francisco State University
SpouseJody Deming
AwardsFellow of the American Academy of Microbiology, 2021 NASA Exceptional Scientific Achievement Medal
Scientific career
Doctoral advisorJohn Liston
Doctoral studentsJulie Huber, Matthew O. Schrenk

Education and academic careerEdit

Baross earned Bachelors of Science degrees in Microbiology and Chemistry from San Francisco State University in 1965. He earned a MS and PhD in Microbiology from University of Washington in 1973. At Oregon State University, he was a postdoctoral researcher (1973-1977), an assistant professor (1977-1983), and an associate professor (1983-1985). He moved to University of Washington in 1985 and has been a full professor there since 1995. He was one of the founding members of the University of Washington Astrobiology program.[2]

Discoveries on volcanic microbial habitatsEdit

Baross was one of the first to show that thermophilic microbes grow in deep-sea hydrothermal vents, work that involved incubating samples on the research vessel's engine block.[3][4][5] His research group has studied microorganisms at Axial Seamount,[6] North Gorda Ridge,[7] and the CoAxial Segment in the Northeast Pacific Ocean,[8] and Lost City Hydrothermal Field.[9]

Baross was among the first microbiologists to sample Mt. St. Helens after it erupted in 1980;[10] this research revealed the succession of anaerobic microorganisms in volcanic lakes after the eruption and the importance of the nitrogen cycle in restoration of the lakes to their former states.[11][12]


Baross' research focuses on extreme environments, particularly volcanic environments, and implications for the origin of life.[1][13] He was among the first to propose hydrothermal vents as a site for the origin of life.[14][15][16] He has coined the term ‘ribofilm’ – a proto-biofilm that may have acted as the first living organism.[17] Baross advocates the idea that key metabolic pathways, in particular those involving metalloenzymes, are rooted in geochemical reactions on mineral surfaces. He is therefore a major proponent for the exploration of icy moons like Enceladus which was discovered to be geochemically active and may favor the production of essential biomolecules.[18] His recent contributions stress the importance of an environmentally diverse planetary surface with active hydrological and geological cycles as an ideal setting for prebiotic reaction networks.[19]

Baross chaired two National Academy of Sciences task groups on origins of life topics: the Committee on the Origins and Evolution of Life (2000-2004) and the Group on the Limits of Organic Life in the Universe (2004-2007). These groups explored the possibility of "weird life" based on alternative substrates.[20] He has served on six national and international planetary protection committees. He is the co-author of the textbook "Planets and Life: The Emerging Science of Astrobiology."[21]

Service and honorsEdit

Baross is a Fellow of the American Academy of Microbiology,[22] chair of the Steering Committee of the International Census of Marine Microbes,[23] and involved in collection of the hydrothermal vent sulfide chimneys on display at the American Museum of Natural History.[24] He was the 2021 recipient of the NASA Exceptional Scientific Achievement Medal and was the featured scientist for December 2021 in the 2021 NASA Science Calendar.[25]


  1. ^ a b Sullivan, Florence (2017-03-07). "Celebrating Hydrothermal Vents!". Geospatial Ecology of Marine Megafauna Laboratory. Retrieved 2021-07-09.
  2. ^ "Prof. John Baross Featured in New NASA Calendar! – uwastrobiology". Retrieved 2021-07-09.
  3. ^ Baross, John A.; Lilley, Marvin D.; Gordon, Louis I. (1982). "Is the CH4, H2 and CO venting from submarine hydrothermal systems produced by thermophilic bacteria?". Nature. 298 (5872): 366–368. Bibcode:1982Natur.298..366B. doi:10.1038/298366a0. ISSN 1476-4687. S2CID 128415368.
  4. ^ Baross, John A.; Deming, Jody W. (1983). "Growth of 'black smoker' bacteria at temperatures of at least 250 °C". Nature. 303 (5916): 423–426. Bibcode:1983Natur.303..423B. doi:10.1038/303423a0. ISSN 1476-4687. S2CID 7584772.
  5. ^ Cone, Joseph (1991). Fire Under the Sea: The Discovery of the Most Extraordinary Environment on Earth--volcanic Hot Springs on the Ocean Floor. Morrow. pp. 196–197. ISBN 0688098347.
  6. ^ Opatkiewicz, Andrew D.; Butterfield, David A.; Baross, John A. (2009-11-05). "Individual hydrothermal vents at Axial Seamount harbor distinct subseafloor microbial communities". FEMS Microbiology Ecology. 70 (3): 413–424. doi:10.1111/j.1574-6941.2009.00747.x. ISSN 0168-6496. PMID 19796141.
  7. ^ Summit, Melanie; Baross, John A. (1998-12-01). "Thermophilic subseafloor microorganisms from the 1996 North Gorda Ridge eruption". Deep Sea Research Part II: Topical Studies in Oceanography. 45 (12): 2751–2766. doi:10.1016/S0967-0645(98)00092-7. ISSN 0967-0645.
  8. ^ Holden, James F.; Takai, Ken; Summit, Melanie; Bolton, Sheryl; Zyskowski, Jamie; Baross, John A. (2001-06-01). "Diversity among three novel groups of hyperthermophilic deep-sea Thermococcus species from three sites in the northeastern Pacific Ocean". FEMS Microbiology Ecology. 36 (1): 51–60. doi:10.1111/j.1574-6941.2001.tb00825.x. ISSN 0168-6496. PMID 11377773.
  9. ^ Kelley, D. S. (2005-03-04). "A Serpentinite-Hosted Ecosystem: The Lost City Hydrothermal Field". Science. 307 (5714): 1428–1434. doi:10.1126/science.1102556. ISSN 0036-8075. PMID 15746419. S2CID 42382974.
  10. ^ Raymer, Steve; Findley, Rowe (1981). "Mount St. Helens Aftermath: The Mountain That Was--and Will Be". National Geographic. Vol. 160, no. 6.{{cite news}}: CS1 maint: date and year (link)
  11. ^ Dahm, Clifford N.; Baross, John A.; Ward, Amelia K.; Lilley, Marvin D.; Sedell, James R. (1983). "Initial Effects of the Mount St. Helens Eruption on Nitrogen Cycle and Related Chemical Processes in Ryan Lake". Applied and Environmental Microbiology. 45 (5): 1633–1645. doi:10.1128/AEM.45.5.1633-1645.1983. ISSN 0099-2240. PMC 242510. PMID 16346298.
  12. ^ Baross, John A.; Dahm, Clifford N.; Ward, Amelia K.; Lilley, Marvin D.; Sedell, James R. (1982). "Initial microbiological response in lakes to the Mt St Helens eruption". Nature. 296 (5852): 49–52. Bibcode:1982Natur.296...49B. doi:10.1038/296049a0. ISSN 1476-4687. S2CID 4334003.
  13. ^ Baross, John A. (2007). "The Limits of Organic Life in Planetary Systems". The National Academies Press. doi:10.17226/11919. ISBN 978-0-309-10484-5.
  14. ^ Corliss, J. B.; Baross, Ja; Hoffman, Se (1981-01-01). "An Hypothesis Concerning the Relationships Between Submarine Hot Springs and the Origin of Life on Earth". Oceanologica Acta. ISSN 0399-1784.
  15. ^ Baross, John A.; Hoffman, Sarah E. (1985). "Submarine hydrothermal vents and associated gradient environments as sites for the origin and evolution of life". Origins of Life and Evolution of the Biosphere. 15 (4): 327–345. Bibcode:1985OrLi...15..327B. doi:10.1007/BF01808177. ISSN 1573-0875. S2CID 4613918.
  16. ^ Helmreich, Stefan (2009). Alien Ocean: Anthropological Voyages in Microbial Seas. University of California Press. pp. 79–80. ISBN 9780520942608.
  17. ^ Baross, John A.; Martin, William F. (2015). "The Ribofilm as a Concept for Life's Origins". Cell. 162 (1): 13–15. doi:10.1016/j.cell.2015.06.038. ISSN 0092-8674. PMID 26140586. S2CID 4229280.
  18. ^ Glein, Christopher R.; Baross, John A.; Waite, J. Hunter (2015). "The pH of Enceladus' ocean". Geochimica et Cosmochimica Acta. 162: 202–219. arXiv:1502.01946. Bibcode:2015GeCoA.162..202G. doi:10.1016/j.gca.2015.04.017. ISSN 0016-7037. S2CID 119262254.
  19. ^ Baross, J.A. (2020), "The Environmental Roots of the Origin of Life", Planetary Astrobiology
  20. ^ Zimmer, Carl (2007-07-06). "Expanded Search for Extraterrestrial Life Urged". The New York Times. ISSN 0362-4331. Retrieved 2020-08-01.
  21. ^ Planets and life : the emerging science of astrobiology. Sullivan, Woodruff Turner., Baross, John A. Cambridge: Cambridge University Press. 2007. ISBN 978-0-521-82421-7. OCLC 144222457.{{cite book}}: CS1 maint: others (link)
  22. ^ "John Baross". College of the Environment. Retrieved 2021-07-22.
  23. ^ "Ocean census uncovers 'new world' of marine microbe life". April 10, 2010. Retrieved 2021-07-22.
  24. ^ Delaney, John R.; Kelley, Deborah S.; Mathez, Edmond A.; Yoerger, Dana R.; Baross, John; Schrenk, Matt O.; Tivey, Margaret K.; Kaye, Jonathan; Robigou, Veronique (2001). ""Edifice Rex" Sulfide Recovery Project: Analysis of submarine hydrothermal, microbial habitat". Eos, Transactions American Geophysical Union. 82 (6): 67–73. Bibcode:2001EOSTr..82...67D. doi:10.1029/01EO00041. ISSN 2324-9250.
  25. ^ "Prof. John Baross Featured in New NASA Calendar! – uwastrobiology". Retrieved 2022-02-07.

External linksEdit