Seems like a great way to smuggle information, or to insure longevity. Encode all of wikipedia into algae, and set it free in the oceans for later species to discover long after any physical artifacts of humanity are gone.

Maybe somebody already did that, and we haven't bothered to try to read the algae.

It was a dyslexic alien named GACT just writing his name over and over.

I've read various science fiction stories based on this. Makes me think of the Tyrell Corp serial number on every scale of Zhorah's snake.

There will be some degradation over time through mutations, and with the short generation time of bacteria, it'll be even more.

Sure, there will be some degradation, but from what I have read, DNA is a far more robust way to store information across millions of years than any archival method yet devised by humans. Perhaps the Voyager golden records will outlast it, but I'm talking about in a terrestrial environment. The error correction is mind blowingly good. For instance, the protein coding sequences of mice and humans are between 85% and 99% identical after about 220 million years of speciation. Granted, a lot of errors in those genes will just kill the host organism, where as a few letter transpositions in the wikipedia article on green sand casting probably won't.