Many microbes are unculturablebecause they do not thrive when extracted from their habitats. Studies conducted within the context of a group allows researchers to see the interactions taking place and use the clues provided to identify the individual roles of the microorganisms.
Photosynthetic microbial mats fix carbon in the day, but it turns out that they produce and ferment a chemical compound called photosynthateregardless of light and oxygen conditions. In areport published online November 29, 2012 in TheISME Journal, a team of researchers including scientists from the DOE Joint Genome Institute, Berkeley Lab and Lawrence Livermore National Lab studied the gene expression patterns (metatranscriptomes) of microbial mats from Central California.
“This work highlights the utility of metatranscriptomics to define pathways for element cycling in complex microbial communities,” the team wrote. “Metatranscriptomics of microbial mats offer the possibility of defining key metabolic pathways in the biogeochemical cycling of carbon.” One of their findings involved a dominant cyanobacterial community, Microleus, which turned out to be able to ferment photosynthate through multiple pathways. They also found a metabolic pathway between Cyanobacteria and Chloroflexi populations in the mats that allowed the photosynthate to be processed in oxygen-poor conditions.