Engineering microbial chemical factories to produce renewable and modified biomaterials

The polymers, such as plastics are ubiquitous and integral in everyday human life with many applications that varies from medical, transport, electrical, construction and packaging. As the current polymer production completely depends on petrochemicals, the manufacturing process are not sustainable along with its high environmental and economic risks. With the advancement of synthetic biology and metabolic engineering, the genomic information and mechanisms of which bacterial cells produce a number of linear polyesters in nature are about to emerge. These materials, known as poly hydroxyl alkanoates (PHA) have a potential advantage over petrochemical derived polymers towards the manufacturing of either thermoplastic or elastomeric polymer materials and are completely biodegradable which could use to produce bioplastics. The plan here is to identify the genes that act up on from the early stages polyester biosynthesis in bacteria and recreate biosynthetic pathways in E. coli and other host organisms. The initial pathway components are derived from a previously reported butanol pathway, which was shown to produce biofuel propane from E. coli cells (Menon et al, 2015: A microbial platform for renewable propane synthesis based on a fermentative butanol pathway. Biotechnology for Biofuels). With the presence of a corresponding transporter genes, it will produce various halogenated polymer units which could be further modified via chemo-catalysis or via incorporating other modifying enzymes. Our aim is to incorporate new modifications (via biosynthetically and chemically) on the derived biopolymers in order to render them readily available for the preparation of bio-molecular conjugates and hybrid biomaterials that could act as a potential and promising new class of biocompatible biomaterials.
Techniques that will be undertaken during the project:
- Bioinformatics- analyzing gene cluster, protein structural prediction and metabolite prediction, protein-protein interactions
- Molecular biology – Manipulation with DNA (PCR, cloning, Gene knockouts etc), site-directed mutagenesis
- Protein expression and purification, optimization and analysis of protein quality
- Metabolic engineering:- pathway construction in different hosts and pathway optimization, separation and characterization of metabolites, analysis of polymers and biomaterials
- Enzymology: enzyme activity assays and assay development, enzyme kinetics (UV-Vis spectroscopy, Fluorescence spectroscopy. HPLC, GC, IR, Mass spec, NMR)
- Protein X-ray crystallography, crystallization and protein structure resolution
- Chemical synthesis:- of metabolites/intermediates, cross coupling chemistry and developing chemo-enzymatic reactions.