Characterisation and Functionalisation of Polyhydroxyalkanoate Granules in Pseudomonas putida KT2440

Polyhydroxyalkanoates (PHAs) are biopolymers synthesised by various microorganisms, offering a sustainable and biodegradable alternative to conventional plastics. This thesis presents a proteomic characterisation of PHA metabolism and granule-associated proteins in Pseudomonas putida KT2440, with a focus on identifying suitable protein candidates for enzyme immobilisation via surface display on PHA granules. Following an overview of key concepts and background literature in Chapter One, Chapter Two examines the proteomic landscape of cells under diverse PHA-accumulating conditions, highlighting key enzymes and regulatory proteins involved in biopolymer metabolism and the most abundantly expressed granule-associated proteins. Chapter Three investigates the functional roles of two novel granule-associated proteins, AceE and OprL, using synthetic and molecular biology approaches to elucidate their contributions to PHA metabolism and granule structure. Chapter Four explores strategies for functionalising PHA granules through enzyme immobilisation, demonstrating their potential as bio-based scaffolds for industrial biocatalysis. Together, these studies advance our understanding of PHA granule composition and function, while establishing their potential as versatile platforms for enzyme immobilisation in biocatalysis and biotechnology.