This is Scientific American 60-Second Science. I'm Shayla Farson.

A couple billion years ago, about 3 billion to be a little more precise, the Earth was

a very different place. It had vast oceans and almost no oxygen in the atmosphere. It was

a place where bacteria ruled. Some of these bacteria used photosynthesis to power themselves,

like plants, but they did it in a strange way, by harnessing light and stealing electrons

from iron. Fast forward about 2 billion years, and those bacteria still exist today. They're

called photofaritrophs, and for decades scientists thought they were pretty rare.

Most people think that all these exotic organisms that do other things in photofaritrophies

is just something that they might have retained from the past.

photofaritobose is a microbiologist at Washington University in St. Louis. In 2015, on a whim,

Bose collected some vials of marine sediment from Whitt's whol Massachusetts and brought

them home to her lab in Missouri. Her students slowly parsed out the individual strains of

bacteria, and they started testing them, one by one, trying to figure out if any of them

still had that ancient metabolism. Bose still remembers the day two of her students

came into her office with the results. They all do it. They all do photofaritrophy,

and I was like, what? No way. No way. I was kind of shocked.

All 15 bacterial strains were photofaritrophs. Maybe they started thinking this trait wasn't

that rare after all. The study appears in the multidisciplinary journal of microbial ecology.

A big reason why they care, beyond just basic scientific curiosity, is the fact that these

microbes are vacuuming up carbon dioxide as they photosynthesize.

If this is truly as common as our data suggests they are, it's possible that these organisms

do make a massive contribution to carbon dioxide fixation as well.

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