This article is courtesy of microscopy-uk.org.uk
How it began…
Philippa Uwins and her colleagues at the University of Queensland, Australia, noticed strange structures growing on sandstone rock samples they had broken open for studying. The rock samples had been retrieved from 3 to 5 Kilometres below the ocean bed where atmospheric pressure is around 2000x normal, and temperatures range between 115 to 170 degs Centigrade; not an easy place for living things to flourish!
This initial discovery was curious enough but when the team found that containers and equipment in their laboratory were being ‘colonised’ by these structures, they realised whatever they had found was growing! Samples were collected from polystyrene petri dishes with sterilised micro-forceps and examined in a powerful SEM (Scanning Electron Microscope) operating at 80 Kvolts.
Examination revealed the structures to be tiny irregular shaped filaments less than 1/100,000 mm (millimetres) wide. Further experimentation and observation in the laboratory showed that the structures were capable of growing and increasing in number spontaneously on freshly fractured rock – becoming visible to the naked eye within 2 to 3 weeks.
What are they..?
Philippa and her colleagues subjected the growing structures to DNA, and chemical composition tests which all gave strong positive evidence that what they had found was alive! The most powerful argument in favour of them being biological life forms comes from the strong positive reaction to DAPI staining – where a DNA-specific probe is used to determine existence of DNA compounds vital to living organisms.
Like bacteria but not bacteria…
Current scientific knowledge suggest that the smallest living organisms are bacteria, but these new structures – dubbed ‘nanobes’ – are in fact much smaller at 1/10 of a bacterium’s size: a nanobacteria, possibly? The scientific community is divided on their thoughts on this with many experts suggesting that nanobacteria are simply too small to contain the all-important genetic material and cell processes associated with small life-forms. The existence of nanobacteria has been suggested for over 10 years. They were one of the lines of evidence used by Nasa scientists to claim that tiny structures in a Martian rock (ALH84001) were fossil bacteria.
The nanobes from the sandstone are not identical to the structures within ALH84001 but they are roughly the same size. Their discovery lends additional weight to the claims about nanofossils because, up to now, the argument against nanofossils being within the martian rock relied strongly on there being no living examples of nano-sized cells.
One of the lead researchers behind the Martian meteorite claims, David McKay of NASA’s Johnson Space Centre, is said to be fascinated by the newly announced discovery and is reported to have said: “It’s something that shows that we just don’t understand the small end of the spectrum. There are implications on that end of the size spectrum for the origin of life.”
Many scientists argue that these tiny structures were formed by geological processes, not biological ones, stating that there is no evidence for life forms smaller than known microbes on Earth. However, there are other scientists and researchers who strongly claim that numerous examples of nanobacteria exist. One of the leading advocates is Dr Robert Folk of the University of Texas. His work involved studying mineral deposits near volcanoes and many years before the public’s exposure to the mars rock announcement, he had claimed to have identified bacteria very much smaller than previously discovered.
He believes such bacteria form the bulk of living things on Earth and may be responsible for the rusting of metal and the “greening” of copper but the tiny organisms have eluded conventional tools and avenues of research.
Opening a can of worms…
It seems that Dr. Philippa Uwins’ discovery has lit a spotlight on a whole area of microscopic study that has been ‘waiting in the wings’ for conventional research and inquiry to catch-up on and investigate further. Other areas of research by different teams and scientists throughout the world are revealing evidence that nanobacteria may have direct effects on humans, causing kidney stones and harmful calcium deposits in the body.
Dr.Uwins’ team has resisted calling her discovery ‘nanobacteria’ and instead has given them the novel name of ‘nanobes’ until more is discovered and researched regarding their evolutionary path and real nature. She accepts that the evidence gained to-date is still open to a variety of interpretations especially as the study of subterranean organisms is still in its infancy with many fresh surprises to come.
Some experts, including Paul Davies one of the worlds leading astrophysicists and philosophers, believe there must be transitional stages to life, where the dividing lines between what is alive and what is not, blur and merge. The smaller an organism is, the more able it would be to form by chance. If life can exist at this level deep within the extremes of the earth, then there is a powerful suggestion that they can live within the rock of other planets – fuelling the belief by many that life is not a one-off chemical freak of our planet but a natural progression of the emergence of life throughout the universe.
If the work done by Dr. Philippa Uwins and her colleagues proves valid in the face of additional investigation and analysis, the discovery of nanobes may become one of the most remarkable and significant discoveries of our age!
Dr. Uwins, along with Queensland colleagues Richard Webb and Anthony Taylor, published their findings in the November/December 1998 issue of American Mineralogist.
A copy of the original research report (in PDF) can be downloaded here.
Images of nanobes