Microplastic-Derived Dissolved Organic Matter Regulates Soil Carbon Respiration via Microbial Ecophysiological...

Area of Science:

• Soil science
• Environmental microbiology
• Biogeochemistry

Background:

• Microbial regulation of soil carbon sequestration is threatened by microplastic pollution.
• Microplastics release carbon compounds (MP-DOM) that microbes can utilize.
• The impact of MP-DOM on soil carbon cycling is not well understood.

Purpose of the Study:

• To investigate the effects of MP-DOM on soil carbon respiration.
• To compare MP-DOM with natural dissolved organic matter (NOM).
• To elucidate the mechanisms behind MP-DOM's impact on soil microbes.

Main Methods:

• Short-term soil microcosm experiments.
• Analysis of spectroscopic and molecular signatures of MP-DOM and NOM.
• Assessment of soil microbial physiological properties and community structure.

Main Results:

• MP-DOM caused 36.9-42.3% higher CO2 emissions than NOM due to greater bioavailability.
• MP-DOM increased microbial quantity, activity, and carbon utilization efficiency.
• Network analysis revealed enhanced microbial capacity to process labile MP-DOM.

Conclusions:

• MP-DOM accelerates soil microbial respiration by altering microbial physiology.
• Microplastic pollution poses a significant risk to soil carbon sequestration.
• Findings have implications for understanding climate change dynamics.