Accelerating Biodegradation: Enhancing Poly(lactic acid) Breakdown at Mesophilic Environmental Conditions with Biostimulants

Including gelatin, skim milk, and ethyl lactate in the compost helps improve the protease activity and stimulates the activity of lactate utilizing microorganisms, thus improving the biodegradation rate of PLA at mesophilic temperatures.

Rafael Auras aurasraf@msu.edu -

Updated from an original article written by Rafael Auras.

New avenues for PLA to be composted in mesophilic conditions.
Can PLA be degraded in home composting setting? The inclusion of gelatin, skim milk and ethyl lactate as biostimulants in the compost matrix helps improve the protease activity and stimulates the activity of lactate utilizing microorganisms respectively, thus improving the kinetic molecular reduction rate of PLA at mesophilic temperatures. This opens new avenues for PLA to be composted in mesophilic conditions.

Accelerating Biodegradation: Enhancing Poly(lactic acid) Breakdown at Mesophilic Environmental Conditions with Biostimulants

Pooja C. Mayekar and Rafael Auras

 Poly(lactic acid) (PLA) has garnered interest due to its low environmental footprint and ability to replace conventional polymers and be disposed of in industrial composting environments. Although PLA is compostable when subjected to a suitable set of conditions, its broader acceptance in industrial composting facilities has been affected adversely due to longer degradation timeframes than the readily biodegradable organic waste fraction. PLA must be fully exposed to thermophilic conditions for prolonged periods to biodegrade, which has restricted its adoption and hindered its acceptance in industrial composting facilities, negating its home composting potential. Thus, enhancing PLA biodegradation is crucial to expand its acceptance. PLA’s biodegradability is investigated in a compost matrix under mesophilic conditions at 37 °C for 180 days by biostimulating the compost environment with skim milk, gelatin, and ethyl lactate to enhance the different stages of PLA biodegradation. The evolved CO2, number average molecular weight (Mn), and crystallinity evolution are tracked. To achieve a Mn ≲ 10 kDa for PLA, the biodegradation rate is accelerated by 15% by adding skim milk, 25% by adding gelatin, and 22% by adding ethyl lactate. This work shows potential techniques to help biodegrade PLA in home composting setting by adding biostimulants.

Did you find this article useful?

You Might Also Be Interested In

Tag List
  • auras,
  • auras lab,
  • research,
  • school of packaging,
  • school of packagingschool of packaging
  • follow us on youtube
  • follow us on instagram
  • follow us on linkedin
Michigan State University
  • Spartans Will.
  • © Michigan State University

MSU is an affirmative-action, equal-opportunity employer, committed to achieving excellence through a diverse workforce and inclusive culture that encourages all people to reach their full potential.

Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Quentin Tyler, Director, MSU Extension, East Lansing, MI 48824. This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.

The 4-H Name and Emblem have special protections from Congress, protected by code 18 USC 707.

We comply with the Federal Trade Commission 1998 Children’s Online Privacy Protection Act (COPPA).