ENGINEERING MICROBIAL PLATFORMS FOR SIMULTANEOUS BIODEGRADATION AND UPCYCLING OF PCL

Abstract

Nowadays, the accumulation of plastic waste in the environment has become a significant global concern, with long-lasting ecological and health impacts. This has driven the urgent need for novel strategies, particularly those targeting the degradation of polyesters, which are widely used but poorly degraded in natural environments [1]. Biological approaches, particularly those utilizing microorganisms, offer a sustainable alternative for addressing plastic waste [2]. In this study, we evaluated the ability of various microbial strains to metabolize polycaprolactone monomers. These included Ralstonia eutropha H16, newly isolated pigmented Streptomyces isolates, Streptomyces albus wild-type strain, as well as a strain evolved via adaptive laboratory evolution, which was selected to better utilize the PCL monomer as a sole carbon source. Initial screening revealed variable growth across the studied microorganisms, which are known to produce valuable bioproducts, such as bioplastics, biopigments, and antibiotics [3] [4]. Additionally, aiming to construct strains that achieve polymer degradation and further metabolize the monomers, plasmids harboring selected polyesterase genes, Se1JFR [5] or DmPETase [6], were introduced into R. eutropha and Streptomyces species. Transformed strains were identified and further analyzed for their polyester-degrading abilities by growth assessment as well as the determination of esterase activity in culture supernatants. Overall, this work contributes to the broader field of microbial upcycling by combining metabolic screening, genetic engineering, and synthetic biology to construct bacterial strains capable of degrading and isolating synthetic polymers.Book of abstract: MikroBioKosmos Society & The Central and East Europe Symposium of Microbial Ecology (#mbkceesme2025), in Thessaloniki, Greece, between 22 and 24 September 2025