Researchers from the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley have discovered 47 new phylum-level bacterial groups in sediments and groundwater samples from an aquifer in Colorado.
The discovery of the 47 new bacterial groups, in addition to the 35 new groups of bacteria discovered last year, represents about half of all known bacterial groups. Aside from the new bacterial groups, the researchers also found about 80 percent of all known bacterial phyla in the same site.
Their discovery, described in a paper published in the journal Nature Communications, could shed some light on how microbial communities work together to live and survive everywhere in the planet, despite the changing climate conditions.
"To better understand what subsurface microbes are up to, our approach is to access their entire genomes," explained Karthik Anantharaman, a researcher at UC Berkeley and first author of the paper, in a statement. This enabled us to discover a greater interdependency among microbes than we've seen before."
For the study, the researchers gathered soil and water samples from a research site near the town of Rifle, Colorado and sent them to the Joint Genome Institute for terabase-scale metagenomic sequencing. The researchers were able to reconstruct more than 2,500 microbes from the samples.
To better understand how these different microbes interact with each other, the researchers conducted metabolic analyses of 36 percent of the organisms detected in the aquifer system, focusing on a phenomenon called metabolic handoff. Previous studies have shown that the waste of other microbes serves as food source for other microbes.
The researchers discovered that carbon, hydrogen, nitrogen, and sulfur cycles are all driven by metabolic handoffs, suggesting high degree of interdependency among the microbial communities. Furthermore, the researchers found that different microbes in the community play a crucial active or backup role in the overall survivability of the community. This suggests that high microbial diversity and interconnections through metabolic handoffs are necessary for high ecosystem resilience.