Development of a two-step biotechnological process for improved PLA biodegradation in the environment

Ministry of Education, Science and Technological Development of the Republic of Serbia, Program of bilateral scientific and technological cooperation between Republic of Serbia and Federal Republic of Germany, no project number, 2023–2025
Coordinator: Dr. Sanja Jeremic, IMGGE
Participants: Marija Nenadovic, Vukasin Jankovic, Brana Pantelic

Environmental plastic pollution is a vast issue, urging for sustainable solution such as replacement of petroleum-based plastic with bioplastic materials. Polylactic acid (PLA) stands out, since it can be produced from natural sources and at the end of its life, eventually, it can be returned to the soil by composting. At the moment, PLA has the largest market share of bioplastics and great potential to successfully replace fuel-based polymers in a wide range of applications. However, despite its natural origin, slow degradation of PLA in the environment limits its application. PLA is not significantly susceptible to bacterial attacks in soil or sewage under ambient conditions, since it must first be hydrolyzed at elevated temperatures to reduce the molecular weight and make it amenable to biodegradation. Post-consumer PLA can be composted only in not readily available industrial composting facilities. The additional challenge is to develop technologies to upcycle bioplastics. Upcycling in this context means transforming them into new materials or products of better quality or for better environmental value, ensuring that micro-plastics are avoided.

Therefore, to make PLA more commercially attractive, this project intends to upgrade the fate of not-readily biodegradable PLA in the environment by developing two-step biotechnological process that combines novel biomaterial pretreatments and enhanced bacterial and enzymatic degradation. The first step will include combination and optimization of ultrasonication, UV photodegradation and dielectric barrier discharge plasma as pretreatment technologies, to find an approach that most effectively alters PLA surface properties thus allowing improved adhesion of both bacteria and enzymes. Next step will involve the development of a biodegradation kit comprised of synthetic consortium developed from best-in-class single bacterial strains, and bacterial enzymes with the improved activity towards PLA degradation.