“We found that our field results were consistent with our lab culture experiments, and with the hypothesis that the main carbon source for these endolithic communities is the local carbonate,” Garcia-Pichel said.

The research team speculates that the discovery of a new mother lode, a potentially inexhaustible carbon source found throughout the crust of the earth and oceans coral reefs, may have given cyanobacteria an important competitive advantage and ecological niche during their early evolutionary history, more than 2 billion years ago — long before animal life came onto the scene in the Cambrian explosion period.

“One could speculate that an evolutionary advantage of boring may have come about as a means to circumvent dissolved inorganic carbon limitation in benthic microenvironments,” Guida said. “Given the old history of cyanobacterial euendoliths in the fossil record, this may have been an ancient adaptation.”

Not only has the team helped prove the physiological mechanisms of microorganism boring, but also for cyanobacteria, given new meaning to the time-worn adage of drawing blood from a stone.

“Interestingly, the process that these endolithic microbiomes carry out, converting solid carbonates into biomass, could constitute a potential solution for helping draw excess atmospheric carbon dioxide into a stable, storable form, if we could only get it to act in reverse,” Garcia-Pichel said.

The project was funded by a grant from the National Science Foundation. 

Joe Caspermeyer

Manager (natural sciences), Media Relations & Strategic Communications