A New Niche for Life at Low G

[BillTre]

Microgravity reshapes bacteriophage–host coevolution aboard the International Space Station

Abstract:

Bacteriophage–host interactions play a fundamental role in shaping microbial ecosystems. While extensively studied on Earth, their behavior in microgravity remains largely unexplored. Here, we report the dynamics between T7 bacteriophage and Escherichia coli in microgravity aboard the International Space Station (ISS). Phage activity was initially delayed in microgravity but ultimately successful. We identified de novo mutations in both phage and bacteria that enhanced fitness in microgravity. Deep mutational scanning of the phage receptor binding domain revealed striking differences in the number, position, and mutational preferences between terrestrial and microgravity conditions, reflecting underlying differences in bacterial adaptation. Combinatorial libraries informed by microgravity selections yielded T7 variants capable of productively infecting uropathogenic E. coli resistant to wild-type T7 under terrestrial conditions. These findings help lay the foundation for future research on the impact of microgravity on phage–host interactions and microbial communities and the terrestrial benefits of this research.

This uses well developed research organisms (E. coli and the T7 phage). Many molecular details are known about their functions. Entire genetic sequences are already known for these guys (with small genomes), so figuring out molecular changes is simplified. Changes were found in the T7 phage (virus)) a receptor that binds an E. coli surface protein. This is the first step in successfully infecting a cell.

A possible scenario might be:
Things are different out there in space. Different traits will be selected for.
They will be better adapted to that environment over time and will therefore thrive there. This depends upon a long continuous existence of their particular low G environment.

 

[javisot]

https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3003568
Interesting article. Assuming the conclusions are correct, can we then say that under conditions of greater gravity than Earth's there would be more replication, therefore, a higher bacterial mortality rate and consequently less coexistence?

If this is correct, it seems like a detail to keep in mind when searching for life in the universe, since under certain gravitational conditions (microgravity, terrestrial or hypergravity) it would be less likely to find phages and bacteria naturally.

 

[AlexB23]

Microgravity reshapes bacteriophage–host coevolution aboard the International Space Station

Abstract:

This uses well developed research organisms (E. coli and the T7 phage). Many molecular details are known about their functions. Entire genetic sequences are already known for these guys (with small genomes), so figuring out molecular changes is simplified. Changes were found in the T7 phage (virus)) a receptor that binds an E. coli surface protein. This is the first step in successfully infecting a cell.

A possible scenario might be:
Things are different out there in space. Different traits will be selected for.
They will be better adapted to that environment over time and will therefore thrive there. This depends upon a long continuous existence of their particular low G environment.

This bodes well for life surviving in space. Kinda crazy how bacteria and viruses evolved to be more resilient in low gravity conditions.

 

[Ken Fabian]

Interesting but I am not surprised that there would be mutation/selection, ie adaptation, however it isn't clear to me what conditions were critical; the paper was quite 'dense' with unfamiliar terms well outside my limited knowledge store. But it did provoke some questions.

What is the extent to which the effects of microgravity on the organisms directly are significant rather than the effects of microgravity on the medium, which undergoes no convection mixing? Sounds like only diffusion and the effects of any motile bacteria were 'mixing' the medium and adaptation is more about surviving the absence of mixing than gravity. (Perhaps the absence of mixing can be mimicked in 1G?). Not clear how large the packages were - 4ml? For micro-organisms suspended in liquid medium the direct effects of gravity seem likely to be relatively small.

I don't think this tells us anything especially useful about potential for alien life in unexpected places; not like these organisms emerged and fully evolved in such conditions, just able to adapt somewhat to changed conditions arising from microgravity when exposed to it. Nor does it tell us much about how humans, plants, animals and their associated biomes will manage in space habitats, which seem to still require centrifugal 'gravity'. Whether some unique biochemical processes can be developed out of this that can do what otherwise cannot be done here on Earth isn't clear.

 

[BillTre]

Perhaps the absence of mixing can be mimicked in 1G?)

Culturing in semi-solid or low melting point agar is done for collecting clones of non-adherent cells. This should also stop convective fluid flows. Diffusion will proceed.