Raman Microspectroscopy to Trace the Incorporation of Deuterium from Labeled (Micro)Plastics into Microbial Cells

Area of Science:

• Environmental Science
• Microbiology
• Analytical Chemistry

Background:

• Plastic pollution necessitates biodegradable alternatives, especially in agriculture.
• Understanding microbial degradation of plastics is crucial for environmental fate assessment.

Purpose of the Study:

• To elucidate the mechanisms of microbial plastic degradation using stable isotope Raman microspectroscopy.
• To analyze plastic biodegradation at the single-cell level in natural systems.

Main Methods:

• Utilized perdeuterated polylactic acid (dPLA) as a model plastic.
• Employed single-cell stable isotope resonance Raman microspectroscopy to trace deuterium labels.
• Analyzed C-D vibrations in microbial biomass to quantify deuteration.

Main Results:

• Detected deuterium transfer from dPLA into microbial lipids and carotenoids.
• Observed metabolic differences and phenotypic heterogeneity in Sphingomonas koreensis during dPLA incubation.
• Confirmed deuterium uptake in soil bacteria isolates after two weeks.

Conclusions:

• Stable isotope Raman microspectroscopy is effective for studying microbial plastic degradation at the single-cell level.
• Demonstrated the potential of this technique for high-throughput analysis and environmental sample assessment.
• Highlighted the role of bacteria like Sphingomonas koreensis in plastic biodegradation.