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Mirror bacteria research poses significant risks, scientists warn

the-scientist.com

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Re: Mirror bacteria research poses significant risks, scientists warn

#151

Post by Terr_ »

ceejayoz wrote: post #93
gwbas1c wrote: post #52

Some scientists in the Manhattan Project worried that the first nuclear test could trigger a chain reaction that would annihilate the earth. These fears were unfounded. (Granted, atmospheric nuclear weapons testing has its own set of subtle consequences that are gradually becoming more well known.)

> These fears were unfounded. Sure, but it's good to prove that one out before pressing the button.

Especially when there are zero other considerations making you (or the people funding you) think you need to rush past testing.

Re: Mirror bacteria research poses significant risks, scientists warn

#153

Post by throwup238 »

efitz wrote: post #131

Maybe we should manufacture and stockpile mirror antibiotics, in case of accidental or intentional release of such organisms. This appeals to me both as a defensive/protective measure and as a deterrent to others who might look to weaponize such organisms.

How would we test that the mirror antibiotics actually work without developing mirror organisms and exposing ourselves to the associated risks?

They aren’t going to be mirror copies of terrestrial organisms, there’s no guarantee that mirror copies of our antibiotics will work (AFAIK it’s actually very unlikely). Protein binding sites change when mirrored because it’s not just mirror image but a change in how the proteins twist when folding, which is why most of them are sensitive to chirality. Only very simple molecules are likely to behave the same.

Stuff like bleach will still work by denaturing proteins and disrupting the bilipid layer in cell membranes but anything like tetracycline and penicilin that targets peptidoglycan enzymes or ribosomes or other complex biochemistry almost certainly won’t.

Re: Mirror bacteria research poses significant risks, scientists warn

#154

Post by bilekas »

This is so impressive that it's achievable, I maybe morbidly was imagining if we were to be wiped out due to this and another species were able to evolve to study how we died, would they come across these mirror Bacteria and believe they were natural. It all has very "Death Stranding" tones but I'm not a biologist by any means.

Re: Mirror bacteria research poses significant risks, scientists warn

#155

Post by throw310822 »

throwup238 wrote: post #153
efitz wrote: post #131

Maybe we should manufacture and stockpile mirror antibiotics, in case of accidental or intentional release of such organisms. This appeals to me both as a defensive/protective measure and as a deterrent to others who might look to weaponize such organisms.

How would we test that the mirror antibiotics actually work without developing mirror organisms and exposing ourselves to the associated risks? They aren’t going to be mirror copies of terrestrial organisms, there’s no guarantee that mirror copies of our antibiotics will work (AFAIK it’s actually very unlikely). Protein binding sites change when mirrored because it’s not just mirror image but a change in how the prot…

> Protein binding sites change when mirrored because it’s not just mirror image but a change in how the proteins twist when folding, which is why most of them are sensitive to chirality

Wouldn't this pretty much rule out the synthetic creation of mirror bacteria? We should not just be able to rewrite a simple existing lifeform in mirrored version; we should recode all its proteins from scratch so that they keep their function in a mirror version, assuming that that's even possible.

Re: Mirror bacteria research poses significant risks, scientists warn

#156

Post by shaky-carrousel »

That's sensationalism. Mirror bacteria would be at a severe disadvantage as there are no natural mirror aminoacids. Normal bacteria will quickly evolve to consume mirror aminoacids. And there are much much more normal bacteria than any possible mirror bacteria. They would be wiped out pretty quickly.

Re: Mirror bacteria research poses significant risks, scientists warn

#157

Post by danwills »

shaky-carrousel wrote: post #156

That's sensationalism. Mirror bacteria would be at a severe disadvantage as there are no natural mirror aminoacids. Normal bacteria will quickly evolve to consume mirror aminoacids. And there are much much more normal bacteria than any possible mirror bacteria. They would be wiped out pretty quickly.

I reckon I generally agree that it's very unlikely that mirror-bacteria would be viable in the wild!

This is covered in the article in 2 ways though: It says that some nutrients (like glycerol) are achiral - this might mean they could still find a food source in a regular-chirality world. It also mentions that the mirror-bacterial nonstandard-chirality might 'cloak' them from regular-chirality predators (or immune-systems).

I dunno, it does seem pretty far-fetched and I am not a professional scientist so I find it hard to evaluate the risk in any worthwhile way.. but I think it still seems worth considering?

Re: Mirror bacteria research poses significant risks, scientists warn

#158

Post by aydyn »

notfed wrote: post #128
aydyn wrote: post #125

Earlier quoted context omitted.

What's scary about mirrored DNA? DNA is information store proteins are actuators. > would have to evolve an entirely new set of proteins from scratch. Mirrored amino acids already exist in some organisms.

> What's scary about mirrored DNA Exponential growth of a self-replicating cell with zero predators. > Mirrored amino acids already exist in some organisms. You can have an entire planet full of mirror amino acids if you want; that's not the hard part. The hard part is evolving the entire set of mirror transcription proteins.

Where are you getting exponential growth without predators? That simply does not follow logically from any assumptions.

Re: Mirror bacteria research poses significant risks, scientists warn

#159

Post by danwills »

geysersam wrote: post #147

If this is such a powerful niche for an organism to be in, why haven't they already emerged naturally over the 3 billion year history of life on earth?

I think that's a great question!

But I also think it's similar in a way to 'why matter and not antimatter' or 'why ~3d space rather than no structure' (much less obvious the second one!).

But I think the real answer here is touched-on by nmstoker in a sibling comment: We're so far down the energy-gradient of the current-default-chirality on earth, that it would take exploration of an insanely-deep valley for all molecules in a cell (there are zillions even in a bacteria!) to flip the the whole thing to the alternate chirality.

It's a bit like the idea that a good chunk of matter (like even a whole amino acid) could all spontaneously-convert to antimatter at once, sure it's possible in theory but the chances are so low we might as well say it's impossible.

Re: Mirror bacteria research poses significant risks, scientists warn

#160

Post by throwup238 »

throw310822 wrote: post #155
throwup238 wrote: post #153

Earlier quoted context omitted.

How would we test that the mirror antibiotics actually work without developing mirror organisms and exposing ourselves to the associated risks? They aren’t going to be mirror copies of terrestrial organisms, there’s no guarantee that mirror copies of our antibiotics will work (AFAIK it’s actually very unlikely). Protein binding sites change when mirrored because it’s not just mirror image but a change in how the prot…

> Protein binding sites change when mirrored because it’s not just mirror image but a change in how the proteins twist when folding, which is why most of them are sensitive to chirality Wouldn't this pretty much rule out the synthetic creation of mirror bacteria? We should not just be able to rewrite a simple existing lifeform in mirrored version; we should recode all its proteins from scratch so that they keep their…

Yeah I think the risk is completely overblown but after the controversy over COVID and Wuhan gain of function research, bioethics discourse seems to have taken a conservative turn.

Long before we’d be able to bootstrap a fully mirrored organism we’d have to develop synthetic biotech that could easily weaponize something already scary like ebola or hendra virus. Synthetic organisms have so far been paired down versions of existing bacteria, not engineered and assembled from the ground up. Once we’re capable of the latter, mirror organisms are just one entry on a very long list of existential threats.

I think the real risk in the foreseeable future is horizontal gene transfer of chiral checkpoint proteins. In order to insert even a single nontrivial D protein into the genome, we’d have to modify the proteins that make sure everything is L-handed. If those managed to escape into the wild, the results would be completely unpredictable and potentially catastrophic. Bacteria mutate and evolve much faster than mammals so if any of them develop surface proteins that are functionally equivalent but D-handed, they could become resistant to antibiotics and our immune systems.

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