|
July 24, 2006
Part X: Astrobiology
Hyperthermophilic Microorganisms —
A Possibility for Extraterrestrial Life?
Harald Huber,
University of Regensburg
29 min. (slideshow requires QCShow Player)
Audio only (mp3 format)
View as a webpage (quicktime, real player) (notes)
What is accomplished by fire is alchemy — whether in the furnace or in the kitchen stove. And he who governs fire is Vulcan, even if he be a cook or a man who tends the stove.
— Paracelsus, 1493-1541
Thirty years ago it was commonly stated in textbooks that no organic (carbon-based) life could survive at temperatures greater than 70°C, and that pasteurization would be complete at 80°C.
In the intervening decades, we've since discovered life on this planet that cannot survive at temperatures lower than 80°C, with many species of hyperthermophilic archaea having their optimal growth temperatures greater than that of boiling water. One recently discovered species, Pyrolobus fumerii, reaches its upper temperature limit at an astounding 121°C, a temperature at which protein denaturization would have previously been assumed to be complete.
Hyperthermophilic microorganisms are defined to be those organisms that their exhibit optimal growth temperatures above 80°C and represent the upper temperature border of life on our planet. They thrive in continental solfataric (volcanic sulfurous steam) regimes and submarine hydrothermal systems, where they form complex communities.
Hyperthermophiles are highly diverse in their morphologies and metabolic properties. Most are anaerobes which use inorganic redox reactions as energy sources, conditions reminiscent of the earliest Earth. These properties enable them to grow in the absence of sunlight. They are also the most primitive organisms known so far.
In this talk, Harald Huber introduces a nano-sized symbiont/parasite, obtained from a submarine hydrothermal system, representing a new kingdom of Archaea, the "Nanoarchaeota." These organisms are only 400 nm in diameter (in the range of large viruses). "N. equitans" exhibits a genome size of only 490 kb, one of the smallest genomes known so far, thus it offers the possibility of providing extraordinary insights into the evolution of thermophily, of the minimal genetic equipment of cells, and of inter-species communications. Almost no genes for metabolism or biosynthesis could be detected within its genome, which further argues for its status as a symbiont or parasite.
This talk was presented at the 2004 Astrobiology Science Conference in a large tent on the NASA Ames Research Center's grounds. The landing pattern for the adjacent Moffet Federal Airfield that day had the aircraft descending directly over the tent, thus you'll hear a number of jet aircraft landing during Harald's talk.
— Wirt Atmar
Subscribe to the Weekly Notice
If you wish to receive a weekly notice of the current lecture, please send a blank email to:
lectures@aics-research.com
Privacy Policy: Your email address will be shared with no one nor used for any purpose other than sending you the weekly lecture notice.
These Lectures are Sponsored by
AICS Research, Inc.
You can easily create lectures of equal quality yourself.
The internet has obvious promise for the dissemination of instructional material over very large distances and into remote corners of the world. To that end, AICS Research has created two products, QCShow, a freely-downloadable player, and QCShow Author, an inexpensive content authoring tool that produces FM-quality sound and full-screen HDTV-quality slideshows at very low bandwidths.
As an adjunct to that development process, for the past 30 months AICS Research has been recording the highest quality conferences in cosmology, astronomy, planetology, geology, astrobiology, ecology, behavior and evolutionary biology so that these presentations may be viewed by anyone anywhere in the world.
The QCShow Player was designed for both individual viewer and for the classroom, so that you may "team teach" with the lectures. Indeed, you may run the lecture through a classroom projector and your room's sound system and very closely recreate the lecture as it was first presented live, but now with the capacity to instantly pause the speaker and interpose your own commentary wherever you wish.
QCShow Author was similiarly designed to be as simple a mechanism as possible, allowing a single lecturer to create productions equal to the very best of educational television, but very quickly, and at astoundingly low costs.
Copyright Notice: AICS Research asserts no copyright over any of the lectures presented in this series. Whatever copyrights exist, they reside with the original authors. You have been given permission to save these lectures on your local machines if you wish, so long as they are not modified in any manner.
|
