Biochemistry of a Mysterious Microbial Community
Subsurface microbial communities are highly diverse and comprise an enormous fraction of Earth’s biomass, but lack of knowledge related to their ecological function makes understanding their ongoing biogeochemical processes difficult. Using synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectromicroscopy to probe biofilm samples from a cold subsurface sulfur spring, researchers recently determined how bacteria and archaea work together to influence global sulfur and carbon cycles. By revealing the bright spectral signals of akylic and methyl groups, together with sulfur functional groups, SR-FTIR unambiguously identified the bacteria’s sulfur-oxidizing metabolic activity. Archaeal cells, which were the dominant population in this biofilm, showed no such activity, suggesting a thriving mutual metabolism of archaea and bacteria. The research was conducted using resources at the Advanced Light Source at Lawrence Berkeley National Laboratory.
Probst, A. J., et al. 2012. “Tackling the Minority: Sulfate-Reducing Bacteria in an Archaea-Dominated Subsurface Biofilm,” The ISME Journal 7, 635–51. (Reference link)