MP-DOM: A Readily Degradable Carbon Source
Short-term soil microcosm experiments showed that MP-DOM increased soil CO₂ emissions by 36.9%–42.3% compared to natural organic matter (NOM). UV-aged MP-DOM triggered even higher emissions—27%–43% more than non-aged MP-DOM.
The reason lies in MP-DOM’s molecular structure: it is less aromatic, less humified, and contains over 64% labile compounds, compared to only 5.7% in NOM. This makes MP-DOM a more easily digestible carbon source for soil microorganisms.
Single-Cell Evidence with eCyte Technology
To directly assess microbial activity, researchers employed D₂O-labeled single-cell Raman spectroscopy, a core eCyte technology. This method detects C-D bonds from metabolically active cells, enabling precise quantification of activity at the single-cell level.
Results showed that MP-DOM significantly enhanced microbial metabolic activity. In black soil, the microbial activity ratio reached 0.34 ± 0.06 in the MP-DOM group, compared to 0.29 ± 0.07 in the NOM group—direct single-cell evidence that MP-DOM stimulates microbial metabolism.
Advantages of eCyte’s Raman technology:
- Culture-independent – avoids bias from cultivation
- Single-cell resolution – captures true microbial heterogeneity
- Non-destructive – preserves native sample conditions
Microbial Responses and Global Implications
Beyond increased activity, MP-DOM also led to:
- Higher microbial abundance
- Greater carbon use efficiency (CUE): 0.73–0.75 vs. 0.55–0.60 in NOM groups
- Enrichment of plastic-degrading microbial taxa
Global estimates suggest plastic waste in terrestrial environments may release 0.28–10.15 million tons of CO₂ annually, with hotspots in Sub-Saharan Africa, South Asia, and Southeast Asia.