[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.

[Aerroon]

I thought the same thing initially, but I'm not as convinced after looking a bit more into it. Ie I think it's a possible risk.

>as there are no natural mirror aminoacids. Normal bacteria will quickly evolve to consume mirror aminoacids.

There are and they already have:

>D-amino acids are toxic for life on Earth. Yet, they form constantly due to geochemical racemization and bacterial growth (the cell walls of which contain D-amino acids), raising the fundamental question of how they ultimately are recycled. This study provides evidence that bacteria use D-amino acids as a source of nitrogen by running enzymatic racemization in reverse. Consequently, when soils are inundated with racemic amino acids, resident bacteria consume D- as well as L-enantiomers, either simultaneously or sequentially depending on the level of their racemase activity. Bacteria thus protect life on Earth by keeping environments D-amino acid free.

https://pubmed.ncbi.nlm.nih.gov/24647559/

On the one hand, this does indicate that the "mirror bacteria" might not starve immediately, but on the other hand it shows that "non-mirror bacteria" would already be there in large numbers.

[kragen]

It would hardly be beyond plausibility for an ingenious researcher to solve the problem of having to feed her mirror bacteria expensive L-glucose by endowing them with an enzyme to enantiomerize cheap and abundant D-glucose. Or, as you implicitly suggest, for the genome she's using to contain such an enzyme already, lurking undetected.

[danwills]

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?

[cogman10]

I think regular microbiology would pretty quickly adapt to the mirrors. Evolution is crazy that way.

But multicellular organisms would be at a huge disadvantage. We don't have offspring every second, so adapting to the mirrors would be nearly impossible. They'd be able to cause havoc in plant and animal life that has mechanisms for dealing with regular bacteria.

[Symmetry]

Bacteria can often synthesize all 20 amino acids themselves if they have enough carbon and nitrogen. They don't need to ingest existing amino acids from the environment.