James Smith

And it turns out that there's really interesting experimental evidence from E. coli, natural chirality E. coli, so just normal E. coli, a type of bacterium that's very commonly studied, that you can grow it on completely achiral carbon sources as food.

So you can basically feed it only achiral food sources and it will still grow.

Okay.

And from the perspective of a myrobacterium, an achiral food source looks exactly the same as it does from the perspective of a normal chirality E. coli.

So you can just directly infer that the myrobacterium would be able to grow on the same things.

And then we know that those nutrients, those achiral nutrients that E. coli have been shown to be able to grow on are present in human blood at concentrations that would be sufficient to enable growth.

There is some uncertainty here.

So they're going to have some fitness disadvantage.

They're going to probably grow a bit more slowly than they might otherwise.

But this is assuming that we're just taking an exact mirror of a natural E. coli.

The thing I'm most worried about is a malicious actor doing this.

In that case, if you're trying to cause harm, you would engineer into that bacterium the ability to consume common chiral nutrients like glucose.

And in that case, you would no longer have this nutritional constraint.

And I think it's pretty hard to get out of the conclusion that if someone was trying to cause harm, they wouldn't be able to engineer around some of these constraints.

There's already a blueprint for how you would introduce the ability to consume D glucose, which is the common form of glucose.

um there's a alpha proteobacterium that can metabolize mirror glucose so there's one that we already know about in the world that can metabolize mirror glucose and so you could use that pathway but in its mirror form and engineer that into great yeah into your mirror bacterium and then it would be able to consume uh to consume normal glucose and that's a very very common nutrient

Something we haven't talked about is if you were to make myrobacteria for industrial applications, you probably also would want to engineer them so that they could consume common nutrients because those nutrients are going to be easier to get hold of to grow it.

So let's say you were making myrobacteria to produce drugs, which is one thing that people have been interested in.

Then you'd probably want to engineer the bacterium to be able to consume glucose.

And that means that the risk of an accident there would be would be high.