Slashdot Mirror
UV-Resistant Micro-Organisms Discovered In the Stratosphere
junglee_iitk writes "Three new species of bacteria, which are not found on earth and highly resistant to ultraviolet radiation, have been discovered in the upper stratosphere by some Indian scientists. These bacteria, which do not match any species on earth, were found in samples collected through a balloon sent up to the stratosphere in April 2005. The payload consisted of a cryosampler containing 16 evacuated and sterilised stainless steel probes. Throughout the flight, the probes remained immersed in the liquid neon to create a 'cryopump effect.' These cylinders after collecting air samples from different heights ranging from 20 to 41 km were parachuted down and safely retrieved, it said." Here's the Indian Space Research Organisation's press release on the discovery. Adds an anonymous reader: "This paper in International Journal of Astrobiology [PDF] speculates how microorganisms reach the stratosphere."
This is completely wrong. They're resistant to UV because the upper atmosphere is constantly bombarded by UV rays. Clorox and UV rays' methods of cell destruction are completely different. In fact, they are probably less resistant to bleach/antibiotics etc than bacteria down here because they've never been exposed to it.
Mechanisms for resistance radiation damage are extremely old in life. Half of Earth's history there was insufficient free oxygen to produce the productive ozone layer. Yet bacteria evolved mechanisms to colonize the energy rich top inches of the ocean surface and resist UV damage.
Many of these same chemical pathways were co-opted in aerobic cells. Free oxygen is toxic to many cells and parts of cells. Yet they figured out how to incorporate the toxic mitochondria energy engines. Mitochondria help cells generate an order of magnitude more energy than aerobic cells, setting the stage for later mobile animal life which requires lots of energy.
When you are unicellular, brownian motion counts as a mass transit system...
In physical space, not far. A mere 10km.
In parameter space (e.g. factors needed to support life sustainably), pretty far. By comparison, the distinction between the stratosphere and the north pole as an ecological niche is considerably greater than that between the north pole and an equatorial rain forest. Keeping in mind that the distance from the equator and the pole is 10,000km, one might say for poetic purposes (you claim to be an English major after all) that the distance between the surface of the Earth and the stratosphere in their capacities to support life is, at a minimum, over at thousand times greater than their physical separation.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
The biochemical energy put into repairing DNA or heat-stable polymerases could have been put into reproduction, for example.
So they'll eat us at a slower rate than they would if they didn't have to have multiple resistance :-P
Just kidding, sorta. As I understand it, those plasmids conferring multiple antibiotic resistance are pretty small compared to bacterial chromesomes, are replicated extremely efficiently, and don't really slow the bugs down to where that wouldn't be a problem. When I make ampycillin resistant E.Coli and grow them in amycillin , they don't seem to go much slower than nonresistant bugs on non-selective media. Granted, I'm not timing them or looking very closely, but I really can't tell a difference. And how much would the extra time for reproduction really help you if it's growing in you? Even if it doubles it's reproduction time, we're still talking a matter of minutes or hours, and it would still grow exponentially. It's still going to reproduce faster than any cancerous cells, right?
It seems to me that the bigger hurdle for a pathogen is avoiding or defeating our immune systems, that seems like a much more complex challenge than being resistant to an antibiotic, and clearly there is no tradeoff there.
UV resistance of course isn't much of an issue, as you typically wouldn't be using UV to treat a bacterial infection, but I don't think it's at all safe to assume that being resistant to one thing makes a bug safer in other ways.