Nanobacterium

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"Nanobacterium"
Scientific classification
Domain:
Phylum:
Class:
Order:
[not assigned]
Family:
[not assigned]
Genus:
"Nanobacterium"

Ciftcioglu et al. 1997[1]
Species
  • "
    Nanobacterium sanguineum
    " Ciftcioglu et al. 1997
Structures found on meteorite fragment Allan Hills 84001

Nanobacterium (

abiotic nature.[5][6] One skeptic dubbed them "the cold fusion of microbiology", in reference to a notorious episode of supposed erroneous science.[7] The term "calcifying nanoparticles
" (CNPs) has also been used as a conservative name regarding their possible status as a life form.

Research tends to agree that these structures exist, and appear to replicate in some way.[8] However, the idea that they are living entities has now largely been discarded, and the particles are instead thought to be nonliving crystallizations of minerals and organic molecules.[9]

1981–2000

In 1981 Francisco Torella and Richard Y. Morita described very small cells called ultramicrobacteria.[10] Defined as being smaller than 300 nm, by 1982 MacDonell and Hood found that some could pass through a 200 nm membrane[citation needed]. Early in 1989, geologist Robert L. Folk found what he later identified as nannobacteria (written with double "n"), that is, nanoparticles isolated from geological specimens[11] in travertine from hot springs of Viterbo, Italy. Initially searching for a bacterial cause for travertine deposition, scanning electron microscope examination of the mineral where no bacteria were detectable revealed extremely small objects which appeared to be biological. His first oral presentation elicited what he called "mostly a stony silence", at the 1992 Geological Society of America's annual convention.[12] He proposed that nanobacteria are the principal agents of precipitation of all minerals and crystals on Earth formed in liquid water, that they also cause all oxidation of metals, and that they are abundant in many biological specimens.[12]

In 1996, NASA scientist

ALH84001, a meteorite originating from Mars and found in Antarctica.[13]

Nanobacterium sanguineum was proposed in 1998 as an explanation of certain kinds of pathologic

University of Kuopio in Finland. According to the researchers, the particles self-replicated in microbiological culture, and the researchers further reported having identified DNA in these structures by staining.[14]

A paper published in 2000 by a team led by NIH scientist John Cisar further tested these ideas. It stated that what had previously been described as "self-replication" was a form of crystalline growth. The only DNA detected in his specimens was identified as coming from the bacteria Phyllobacterium myrsinacearum, which is a common contaminant in PCR reactions.[5]

2001–present

In 2004, a

kidney stones. Their results were published in 2004 and 2006 respectively.[4][15] Similar findings were obtained in 2005 by László Puskás at the University of Szeged, Hungary. Dr. Puskás identified these particles in cultures obtained from human atherosclerotic aortic walls and blood samples of atherosclerotic patients but the group was unable to detect DNA in these samples.[16]

In 2005, Ciftcioglu and her research team at NASA used a rotating cell culture flask, which simulates some aspects of low-gravity conditions, to culture nanobacteria suspected of rapidly forming kidney stones in astronauts. In this environment, they were found to multiply five times faster than in normal Earth gravity. The study concluded that nanobacteria potentially have a role in forming kidney stones and may need to be screened for in crews pre-flight.[17]

An article published to the Public Library of Science Pathogens (PLOS Pathogens) in February 2008 focused on the comprehensive characterization of nanobacteria. The authors claim that their results rule out the existence of nanobacteria as living entities and that they are instead a unique self-propagating entity, namely self-propagating mineral-fetuin complexes.[18]

An article published to the

silica solutions that closely resemble primitive organisms.[19] The authors commented on the close resemblance of these crystals to putative nanobacteria, stating that their results showed that evidence for life cannot rest on morphology
alone.

Further work on the importance of nanobacteria in geology by R. L. Folk and co-workers includes study of

ribosomes, and even smaller objects with cell walls and lucent interiors with diameters of 0.05 μm.[25] Culturable organisms on earth are the same 0.05 μm size as the supposed nanobacteria on Mars.[26]

See also

  • Protocell
  • Mycoplasma — smallest known bacteria (300 nm)
  • Nanoarchaeum
    — smallest known archaeum (400 nm)
  • Nanobe — possible smallest lifeforms (20 nm)
  • Parvovirus
    — smallest known viruses (18-28 nm)
  • Prion — smallest known infectious agent (≈10 nm)
  • Ultramicrobacteria — possible dormant forms of larger cells (200 nm)

References

  1. .
  2. .
  3. .
  4. ^ .
  5. ^ .
  6. ^ .
  7. ^ Jack Maniloff, quoted in "The Rise and Fall of Nanobacteria", Young and Martel, Scientific American, January 2010
  8. PMID 18282102
    .
  9. ^ "The Rise and Fall of Nanobacteria", Young and Martel, Scientific American, January 2010
  10. PMID 16345721
    .
  11. ^ A convention has been adopted between researchers to name -or spell- the nanoparticles isolated from geological specimens as nannobacteria, and those from biological specimens as nanobacteria.
  12. ^ a b Folk, Robert L. (March 4, 1997). "Nanobacteria: surely not figments, but what under heaven are they?". naturalSCIENCE. Archived from the original on December 9, 2008. Retrieved 2008-12-20.
  13. S2CID 40690489
    .
  14. .
  15. .
  16. .
  17. .
  18. .
  19. S2CID 11977001. Archived from the original
    (PDF) on 2012-03-01. Retrieved 2009-12-03.
  20. ^ Folk, RL and Lynch. FL (2001) Organic matter, putative nanobacteria and the formation of oolites and hard grounds, Sedimentology, 48:215-229.
  21. ^ Folk, RL and Lynch, FL, (1997) The possible role of nanobacteria (dwarf bacteria) in clay-mineral diagenesis, Journal of Sedimentary Research, 67:583-589.
  22. ^ Folk, RL (2005) nanobacteria and the formation of framboidal pyrite, Journal Earth System Science, 114:369-374
  23. ^ Folk, RL and Carlin J (2006) Adventures in an iron birdbath: nanostructure of iron oxide and the nanobacteria connection, Geological Society of America, Abstracts with programs, v. 38 (3), p. 6.
  24. ^ Kirkland, B and Lynch, FL (2005) nanobacteria, Big Foot and the Loch Ness Monster—what are you supposed to believe?, Geological Society of America, abs. with progr., v. 37:253.
  25. ^ Folk, RL and Kirkland, B, (2007) On the smallness of life: new TEM evidence from biofilm in hot springs, Viterbo, Italy, Geological Society of America, abs. with proper., v. 39 (6) 421.
  26. ^ Folk, RL and Taylor, L (2002) nanobacterial alteration of pyroxenes in Martian meteorite ALH84001, Meteorology and Planetary Science, v. 37:1057-1070.

External links