Rhodopseudomonas palustris is a photosynthetic bacterium capable of metabolising a broad range of substrates. It is a highly robust microorganism with a high tolerance for toxic conditions, making it an ideal candidate for the remediation of waste materials by metabolism. Our societies produce large amounts of waste materials, which require processing and safe disposal, but could instead be used as resources to produce fuel and energy or sustainably recycled into new materials. R. palustris can be used to process waste glycerol (a byproduct of biodiesel manufacture), and naturally produces hydrogen gas (a clean-burning fuel) as a byproduct of this process. R. palustris could potentially be used to bioremediate other waste materials and could be engineered to manufacture other useful products from this process.

This thesis reports discoveries regarding the growth of R. palustris on previously untested substrates and the engineering of R. palustris to improve its utilisation of substrates and add additional metabolic pathways for the sustainable production of valuable compounds. Firstly, new substrates including urea are identified as supporting growth of R. palustris, suggesting that it could be used to process nitrogen-rich agricultural wastes. Nitrogen runoff and pollution pose a significant environmental problem, and safe disposal represents a significant cost to industry. Using R. palustris to bioremediate these wastes, converting them to more valuable materials, would help to offset the costs of waste disposal as well as providing a sustainable source of desirable compounds. Secondly, a genetic manipulation system developed to allow the expression of heterologous genes in R. palustris is presented, and newly engineered strains of R. palustris are characterised that are capable of producing the industrially significant compound cyanophycin when R. palustris is grown on glycerol and urea. Finally, strategies are presented for the future development of R. palustris as a bioremediation system and cell-factory for sustainable biotechnology.