Studying Carbon-13 (13C) metabolism in a microbial community can be a time-consuming and tricky prospect. This is because scientists often have to separate a single species out of the mix for study. However, if particular proteins are produced by a single species within the community, they can sometimes be extracted to yield information about the 13C metabolism of those organisms. A new study describes how the protein photosystem I (PSI) might be used as a ‘reporter protein’ for (13)C metabolism of a cyanobacterium when it is present in a mixed culture of heterotrophic bacteria.

The paper, “Using photosystem I as a reporter protein for ¹³C analysis in a coculture containing cyanobacterium and a heterotrophic bacterium,” was published in the journal Analytical Biochemistry. The work was supported in part by the Exobiology & Evolutionary Biology element of the NASA Astrobiology Program.