How microbes survive clean rooms and contaminate spacecraft
phys.org
phys.org
1) Ralstonia pickettii doesn't really need much to eat, and thus thrives in ultra-pure water systems. Like, you know, the ones used to make medical devices.
2) Stuff in the Burkholderia cepacia complex is naturally resistant to lots of antibiotics, but also tolerates chlorhexidine gluconate and various quaternary ammonium disinfectants. Well, ok, more than tolerates - they'll happily colonize the disinfectant solutions, and then infect whatever you're trying to "disinfect".
3) Deinococcus radiodurans seems almost engineered to survive interstellar travel, but that's probably just a coincidence. Anything that can survive 15,000 Gray is scary.
4) Bacillus altitudinis is pretty weird too - like the name says, it's been found up to 40ish-km, which is an odd place for things to grow.
Why is 3) so resistant against radiation? Does it repair DNA damage faster than it occurs?
Do you mind me asking if you're working in industry or are in academia/research? :)
I don't actually study (3) particularly, nor am I a biologist. As far as I understand, the "how" question is pretty well studied, and is because it's pretty aggressive with DNA repair, and has lots of various tricks to facilitate that and minimize damage from occurring in the first place. The question of "why" is (in my mind) more interesting, and less understood - it may be due to evolving to deal with prolonged dehydration, which is a much more useful ability for life on earth. IDK.
R&D at a startup.
No in the sense that phospholipids and proteins and hydrocarbons in general are delicious to bleach. Exactly like asking if there are bacteria that can survive being incinerated in a fire, at a chemical level the molecules in their cell walls get broken up. There is no simple hack a unicellular organism can apply to survive strong enough bleach or fire, at a very low chemical level its being destroyed. Would silicon based life tolerate bleach? I'd have to think about that a bit.
Yes in the sense that if you play games with very low concentrations you will slowly preferentially breed stronger cells, much as you could breed fire resistant wood, but all wood vaporizes in a strong incinerator. Obviously Homeopathy is not a thing scientifically, a small amount of bleach dumped in a pond won't kill everything in the pond but it will kill the weakest whatever in the lake, leading to increased breeding of stuff resistant to extremely low bleach concentrations. However even in theory I don't think anything could live in a bottle of normal strength bleach.
There are also categorical issues, a very thick layer of algae when splashed with bleach will have the outer layer die and eventually melt off, but the layer underneath will simply regrow. Does that mean algae is resistant in the overall system sense even though it dies really easily? People are usually only interested in systemic success, so sure, its very easy for bacteria to survive bleach based cleaning. A nice thin layer of bulk grease or oil that lasts long enough to protect at least some bacteria underneath that isn't completely removed during the cleaning, there you go, bacteria that survived bleach cleaning, although no bacteria individually can survive full strength bleach, a sufficiently thick layer of grease protecting some bacteria can survive a sufficiently short enough bleach cleaning process.
It seems intuitive to me that if you're maintaining such a clean room the only bacteria that are going to live there are ones hardy enough to survive in those extreme conditions, you're just going to be running an accidental breeding program for bacteria likely to survive on a spacecraft.
As opposed to just assembling all this stuff in a room open to the elements. It would then be completely inundated with bacteria, but none of them would have any selective advantage in being hardy. You could even feed them on purpose by spraying food for them everywhere.
Then when you launch the spacecraft those fat comfortable bacteria would all instantly die because vacuum isn't an environment that's anything like what they've had to deal with, unlike the hardy ones in the clean room, and the few survivors would have no time to develop hardiness. They'd all die within hours from launch.
I personally doubt that this contamination is much of a problem. The planets of the solar system have been dusted in earth rocks containing bacterial spores thrown up by large asteroid strikes for billions of years.
So there's potential there I would imagine in regards to testing that hypothesis. However what mainly bothers me with it is that it doesn't explain the origin of life and why Earth couldn't have original life begin on it.
Unless we can rule out that early Earth conditions would have been too inhospitable for life to start but was sufficient to sustain it I see no reason to think an extraterrestrial origin to Earth life is more likely.
Actually, information is stored as RNA, with DNA as long-term storage (mnemonic: RAM nucleic acid vs disk nucleic acid) and then amino acids are assembled into proteins (hardware) based on that information. Proteins only function as information storage in pathological cases like prions.
But yes, if 'alien' life used the same 20 amino acids, and especially if it has the same mapping from 64 nucleic acid triplets to 20 amino acids, then that's confirmation that it's actually just a earth microbe that escaped or was left behind.
Therefore, yes, life would have diverged sufficiently that scientists should be able to tell the difference.
An extremely expensive although effective approach would be to "seed" the spacecraft with isotopically enriched and documented solvents and food sources such that all the oxygen or carbon or both on the spacecraft, if any contamination DOES exist, would be a peculiar and documented isotope ratio that is different than Mars ratios.
I think we know the natural ratios for Mars in bulk material, so anything immediately found to be growing that matched the documented "salted" isotope ratios obviously was a spacecraft contaminant whereas anything mars ratio was local. Of course bacteria can reproduce fast, so Earth bacteria eating Mars material would rapidly revert to Mars isotope ratios. Still for the first hour on the ground this would likely be usable for life detection experiments. Although it would probably be unimaginably expensive.
Why do you assume so? It's possible a sattelite in the Solar System was contaminated by Earthling bacterias via asteroids and somehow miracalously adapted that environment. If this is true, scientists would find a group of bacteria branched off of bacteria here on Earth a billion year ago or so.
One interesting theory is that life originated outside the Earth (say on Mars) and was transported to Earth at a later time. This theory would explain why LUCA [0] is so complex and why life appears almost as soon the Earth had liquid water [1].
0. https://en.wikipedia.org/wiki/Last_universal_common_ancestor
from the wikipedia article:
>LUCA should not be assumed to be the first living organism on Earth
However tiny the spacecraft's contamination is going to be right next to the sensors making false positives easy. Longer term they will likely all die out, but they could still contaminate samples taken over huge areas for the next decade.
What is a cleanroom's stated goal? Implying the cleanroom's only purpose is for reducing the risk of forward contamination.
Spacecraft will be manufactured in a cleanroom regardless of effectiveness at stopping microbial forward contamination. Foreign Object Debris, payload and bus contamination during manufacture are the primary concerns. For example, dust or condensate on an optical payload would ruin a Discovery class mission.
The stated goal of a clean room is for quality control, reducing microorganism forward contamination is a secondary.
My immediate thought with regard to cleanliness is always moulds.
It’s not clean until it’s been soaked in sodium hypochlorite and sodium hydroxide, UV sterilised, gamma irradiated, then parked in a decaying orbit above the sun.
Especially since no hospital would rely on just ethanol and isopropyl. You'd think they'd at least try to live up to the standards of a hospital.
Of course, I'm not sure how effective that sort of prep would be, but I hope I reduced my risk, at least.
It’s a wonder hospitals don’t require existing wounds to be dressed in touch a way prior to admission.
By that time, you've also 'sterilised' most electronics...
Does the article mention they were used to sterilise or that there weren't other products?
> A highly concentrated, industrial strength heavy-duty cleaner/degreaser. Can be used for light duty washing to heavy-duty steam cleaning.
Kleenol 30 is a mix of
> BENZENESULFONIC ACID, DODECYL‐, SODIUM SALT; (DODECYL BENZENE SULFONIC ACID) (CERCLA).
> Fraction by Wt: 1%
> SILICIC ACID (H2SIO3), DISODIUM SALT; (SILICILIC ACID DISODIUM SALT)
> Fraction by Wt: 1‐4%
> ETHANOL, 2‐BUTOXY‐; (ETHYLENE GLYCOL MONOBUTYL ETHER)
> Fraction by Wt: 12.5%
> GLYCOLS, POLYETHYLENE, MONO(NONYLPHENYL) ETHER; (NONYL PHENOL ETHOXYLATE).
> Fraction by Wt: 1-5%
That is, they weren’t saying “hey, this bullet is ineffective against that tank.” They were saying, “deprived of oil, that tank started eating bullets.”
Makes me wonder why Hibiclens is OK for skin use but not for use on inorganic surfaces like metal or plastic?
This article asserts that this was the result of a clean room failure after the parts were returned to Earth: https://www.space.com/11536-moon-microbe-mystery-solved-apol....
This is not as exciting as the notion that some bacteria might have survived for years inside the lander on the Lunar surface, but it still illustrates the risks of failing to maintain a proper clean room environment.
(We'll probably make self-replicating ones that destroy all life.)
Bacteriophages are what you want, you just need to find the right strain.
Roundworms, acari, springtails, and such eat bacteria though; they're apparently known collectively as detritivores.
Plus, phages are viruses, unlike roundworms and the like, they can survive centuries without food.
They also, as mentioned, account for 30% of death in marine life every day, biggest killer organism on this planet.
There is phage-therapy too, an alternative to anti-biotics, where you are given a dosage of phages in an infected area. Due to their nature they only attack specific strains of bacteria and can easily eradicate the entire population within a few hours.
I'm sure this would present some design challenges, but it doesn't seem to me like it would be insurmountable.
https://www.nps.gov/yell/learn/nature/life-in-extreme-heat.h...
As an interesting tangent, the engineering used to design a heat-resistant spacecraft might be re-used to design a long-lived Venus surface probe.