Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 29 (1), 73-93

Post-Viking Microbiology: New Approaches, New Data, New Insights

Collaborators, Affiliations

Post-Viking Microbiology: New Approaches, New Data, New Insights

K H Nealson. Orig Life Evol Biosph.


In the 20 years since the Viking experiments, major advances have been made in the areas of microbial systematics, microbial metabolism, microbial survival capacity, and the definition of environments on earth, suggesting that life is more versatile and tenacious than was previously appreciated. Almost all niches on earth which have available energy, and which are compatible with the chemistry of carbon-carbon bonds, are known to be inhabited by bacteria. The oldest known bacteria on earth apparently evolved soon after the formation of the planet, and are heat loving, hydrogen and/or sulfur metabolizing forms. Among the two microbial domains (kingdoms) is a great deal of metabolic diversity, with members of these forms being able to grow on almost any known energy source, organic or inorganic, and to utilize an impressive array of electron acceptors for anaerobic respiration. Both hydrothermal environments and the deep subsurface environments have been shown to support large populations of bacteria, growing on energy supplied by geothermal energy, thus isolating these ecosystems from the rest of the global biogeochemical cycles. This knowledge, coupled with new insights into the history of the solar system, allow one to speculate on possible evolution and survival of life forms on Mars.

Similar articles

See all similar articles

Cited by 4 PubMed Central articles

  • Bacterial Biodiversity From Roopkund Glacier, Himalayan Mountain Ranges, India
    S Pradhan et al. Extremophiles 14 (4), 377-95. PMID 20505964.
    The bacterial diversity of two soil samples collected from the periphery of the Roopkund glacial lake and one soil sample from the surface of the Roopkund Glacier in the …
  • Microbial Life and Temperature: A Semi Empirical Approach
    L Garzón. Orig Life Evol Biosph 34 (4), 421-38. PMID 15279175.
    Many groups have examined the effect of temperature on the survival of microorganisms, resulting in the development of several models. Some of these models are based on t …
  • Survival of Microorganisms Under the Extreme Conditions of the Atacama Desert
    K Dose et al. Orig Life Evol Biosph 31 (3), 287-303. PMID 11434107.
    Spores of Bacillus subtilis, conidia of Aspergillus niger, versicolor and ochraceus and cells of Deinococcus radiodurans have been exposed in the dark at two locations (a …
  • Life: Past, Present and Future
    KH Nealson et al. Philos Trans R Soc Lond B Biol Sci 354 (1392), 1923-39. PMID 10670014. - Review
    Molecular methods of taxonomy and phylogeny have changed the way in which life on earth is viewed; they have allowed us to transition from a eukaryote-centric (five-kingd …


    1. Appl Environ Microbiol. 1994 Dec;60(12):4517-26 - PubMed
    1. Sci Am. 1996 Oct;275(4):68-73 - PubMed
    1. Annu Rev Microbiol. 1984;38:515-50 - PubMed
    1. Nature. 1996 Nov 7;384(6604):55-9 - PubMed
    1. Nucleic Acids Res. 1994 Sep;22(17):3485-7 - PubMed

LinkOut - more resources