Exploring polyethylene degrading capabilities of bacteria using bioprospecting and synthetic biology

<p dir="ltr">Plastic waste is a massive global problem, causing significant environmental concerns on land and in aquatic environments. Of the > 390 million tonnes of plastics produced in 2021, ~27% was polyethylene (PE), which is particularly difficult to break down and currently is not readily recyclable. Fortunately, larvae of the beehive pest <i>Galleria mellonella</i> are known to efficiently consume PE, but little is known about how this occurs. My first aim of this thesis was to isolate and identify bacteria in the <i>G.</i> <i>mellonella</i> larvae microbiome potentially driving PE degradation. By feeding larvae a PE diet, culturing larval homogenate on PE-containing agar plates and further differential plating, I successfully isolated candidate PE degrading bacteria and used 16S PCR for species identification. Secondarily, I set out to assess the validity of the most well studied PE degrading gene and explore potential new PE-degrading genes, identified previously in my laboratory. For this, I synthesised gene constructs of potential PE-degrading genes and introduced them into non-PE degrading <i>E. coli</i>. For both aims, PE-degradation ability was assessed using various microscopy and chemical methods. Together these approaches provided insight into the PE degradation potential of bacteria, laying a groundwork for further experimentation.</p>