Live tracking metabolic networks and physiological responses within microbial assemblages at single-cell level

Area of Science:

• Microbiology
• Metabolomics
• Spectroscopy

Background:

• Directly monitoring dynamic, spatially resolved microbial interactions in living cells is challenging.
• Understanding microbial metabolic exchange is crucial for natural and engineered systems.

Purpose of the Study:

• To develop a novel method for live tracking of microbial metabolic interactions at the single-cell level.
• To quantify nutrient fixation and transfer rates in microbial assemblages.

Main Methods:

• Coupling single-cell Raman microspectroscopy with 15N2 and 13CO2 stable isotope probing (SIP) in a microfluidic culture system (RMCS-SIP).
• Establishing and validating Raman biomarkers for N2 and CO2 fixation in cyanobacteria.
• Designing a microfluidic chip for simultaneous cultivation and Raman acquisition.

Main Results:

• Achieved temporal tracking of intercellular and interspecies N and C metabolite exchange.
• Quantified single-cell N and C fixation and bidirectional transfer rates using SIP-induced Raman shifts.
• Captured physiological responses of active cells to nutrient stimuli.

Conclusions:

• The developed RMCS-SIP platform enables noninvasive, live-cell imaging of microbial interactions with single-cell resolution.
• This approach advances the understanding of microbial community dynamics and metabolic functions.
• The platform can be extended for diverse microbial interaction studies, benefiting societal applications.