PubMed · 2026-04-20
Researchers found that common plastics — including PET (used in bottles) and PLA (a compostable plastic) — do measurably break down when buried in soil, but how fast depends heavily on the soil's chemistry and which microbes live there. Alkaline, mineral-rich soils hosted microbial communities that degraded plastic surfaces the most, offering a path toward using soil biology to clean up plastic pollution.
PET plastic showed up to 38% reduction in surface carbonyl index after 300 days, while PLA showed up to 36%, confirming measurable biodegradation in real soil conditions
Plastic surface hydrophobicity dropped by 52% for PET and 26% for PLA, with alkaline, carbonate-rich, higher-conductivity soils driving the greatest transformation
Plastic exposure significantly restructured soil microbial communities, enriching known plastic-degrading bacteria (Bacillus, Burkholderia, Pseudomonas) around PET and broader metabolic specialists around PLA