Cow Feces Bacteria Successfully Break Down HDPE Plastic Within 40 Days

Cow Feces–Derived Bacteria Show Promising Ability to Degrade HDPE Plastic

A new scientific study has uncovered a powerful natural solution for tackling high-density polyethylene (HDPE) pollution. Researchers isolated two bacterial strains from fresh cow feces—Brevibacillus parabrevis EVB2 and Bacillus velezensis EVB8—and found that both could biodegrade HDPE film without any chemical or physical pre-treatment.

Measurable Degradation in Just 40 Days

During a 40-day incubation period, the bacteria used HDPE as their sole carbon source and significantly reduced the weight of the plastic:

EVB2: 3.78% ± 0.90 weight loss
EVB8: 1.84% ± 0.75 weight loss

Both strains also showed strong metabolic activity, with EVB2 producing over 104 mg of CO₂, indicating active polymer breakdown.

Chemical and Structural Evidence Confirms Biodegradation

The research used advanced analytical methods to validate plastic degradation, including:

SEM, which revealed cracks and erosion on the HDPE surface
FTIR, showing the appearance/disappearance of chemical bonds
XRD, indicating a decrease in crystallinity
GC–MS, identifying degradation byproducts such as alkanes

The clear structural and chemical changes confirm that both bacterial strains directly altered the HDPE polymer.

A Sustainable Alternative for Plastic Waste Management

This study highlights bovine feces as an underexplored microbial reservoir with potential for discovering new plastic-degrading bacteria. Importantly, both EVB2 and EVB8 degraded HDPE without any pre-treatment, making them promising candidates for future bioremediation strategies.

The authors recommend longer incubation studies and further exploration of microbial enzymatic pathways to maximize degradation efficiency.

Reference

Trad, B., Branes, Z., Betouil, A.A. et al. Biodegradation of high-density polyethylene (HDPE) using bacterial strains isolated from fresh bovine feces. Biodegradation 36, 111 (2025). https://doi.org/10.1007/s10532-025-10205-6