Exploring spatial patterns of microbial activity and interactions using Raman microspectroscopy
The interactions between bacteria can have significant and wide-ranging effects on diverse ecosystems, yet our ability to directly and non-destructively observe these interactions in a dynamic manner is limited. Existing experimental systems do not capture the physical and chemical complexity inherent in natural systems. This project integrates microfluidics, Raman microspectroscopy, and isotopic labeling to enable the real-time, dynamic visualization of microbial interactions.
Raman microspectroscopy is a powerful technique for the analysis of microbial cells at the single cell level. A single Raman spectrum of a microbial cell can be acquired within seconds and yields data about its abundant chemical bonds, such as those derived from nucleic acids, proteins, lipids, and carbohydrates. Raman spectra provide chemical fingerprints that are highly sensitive to the cellular biochemical composition and physiological state of the cell. Raman also allows substrate utilization to be monitored: by providing 13C labelled variants of compounds of interest, assimilation of 13C into cellular biomass can be detected by distinctive shifts in peaks in the Raman spectrum. Raman microspectroscopy is non-destructive, and the activity of organisms can be monitored over time without affecting their physiology.
In this project, a novel microcosm-imaging platform will be established and used to visualize interactions in realistic, heterogeneous, three-dimensional environments. This will serve as a robust system to manipulate, perturb, and observe microbial activity in situ that is also flexible enough for diverse applications by the broader scientific community. This approach will improve our understanding of how complex microbial communities are generated, maintained, process substrates, and may be usefully manipulated.
This project is funded by the U.S. Department of Energy.