Tiny microbe could be 'perfect time capsule' for messaging future civilisations

Davis's suggestion isn't the first to propose using nucleic acid as a memory solution.

Web Desk – If humanity fails to find a way through this train wreck of a climate crisis, we might want a form of record-keeping that doesn’t decay after a generation or two. You know, just to let future intelligences know we had some redeeming qualities.

Artist Joe Davis from Harvard University thinks he has a solution. If you really want to leave your 30th-century descendants a work of art, embed it in the genes of the salt-loving microbe, Halobacterium salinarum.

Davis’s suggestion, described in a new paper, isn’t the first to propose using nucleic acid as a memory solution. Three years ago, Microsoft also announced plans for devising technology that would see them store information in DNA data banks.

It’s not hard to see the appeal of this kind of data storage. Depending on who you ask and how you crunch the numbers, all of the chromosomes in a single human cell could match a pair of CDs for storage space.

That extreme compactness means the sum of all the world’s data could, in theory, fit into a double-garage as strings of A, G, T, and C.

Given the rate at which that library of data grows every year, we might want to think about efficient ways to contain it.

It’s not just a nice theory. Researchers have previously crammed books, images, and even movies into a format that life has been using for billions of years.

Unfortunately, if you wanted every Marvel film in the MCU translated into a droplet-sized DVD, you’d still need to have plenty of patience. Companies are making headway on automating and speeding it up, but it’s not exactly the future of Netflix.

But in addition to its small size, the idea has one other appealing factor.

Unlike that stash of VHS tapes at the top of your closet, or even the CD-ROM games buried in your drawer, a properly stored DNA memory bank can be relied upon to preserve its information for the long haul.

That’s all well and good if you have a deep freezer and aren’t expecting a major interruption to electricity in the next thousand years or so, but how do we ensure our data survives in the long term?

Researchers suggest the best method could be to find a hardy little archivist that ensures the data is kept in check the old-fashioned way without our help.

"If all other life is destroyed on Earth, and this is the only thing left, maybe that information could propagate on its own," biological engineer Jeff Nivala from the University of Washington tells Steve Nadis at Science Magazine.

In Davis’s study, his nomination for the best bug for the job isn’t a bacterium, strictly speaking, but a salt-tolerant microorganism called an archaeon.

H. salinarum is right at home in highly salty environments, so it’s proven it can put up with the stress of a hostile wasteland.

Buried in salt and deprived of nutrients, it simply stays put, shutting down and refusing to reproduce until conditions improve.

Whereas oxygen and radiation would corrupt a CD in short order, H. salinarum would use its talent for repairing oxidative damage to ensure all of the data was kept in relatively pristine condition for centuries or more.

Davis doesn’t have a background in biology, himself, but hasn’t let that stop him working with a more qualified team of researchers to demonstrate the microbe’s potential over other candidates.

For a code to preserve, Davis created two 3D art pieces (seen below) inspired by a rather apt Russian folktale called "Koschei the Deathless", which were reduced to a string of coordinates and translated into base codes before being inserted into a spot in H. salinarum’s genome.

Even after the altered cells copied themselves several times over, their precious message remained stable.

While the intent may sound more sci-fi than practical, there’s still much to learn about H. salinarum’s metabolism that this kind of research could reveal.

The next phase is to store them away in salt for a number of years before checking in on the code once again, and perhaps tag some proteins to see if they move around while the tiny archivist sleeps.

The study is available on the pre-print website bioRxiv.org.