21ENGBIO_Metagenomic Engineering Platform for Bioremediation

Human impact upon the environment is among the biggest threats to the planet and humanity. Contamination of the natural environment with xenobiotics (e.g., with heavy metals, plastics, halogenated compounds etc) causes significant challenges in terms of containment and remediation. For example, the global appetite for plastic products has transitioned our planet into an era of the "Plastic Age". Polyethylene terephthalate (PET) plastic is the most commonly used plastic in the packaging of beverages, food and pharmaceuticals. Although regarded as non-toxic and 100% recyclable, single use convenience-sized PET bottles have made PET plastic the third most collected debris in beach clean-ups in more than 100 countries and is overwhelmingly omnipresent in the terrestrial ecosystem.

Microbial and enzyme-based plastic waste biodegradation and recycling offer promising solutions to address plastic bio-recycling due to the use of benign conditions and potential as a cost-effective environment-friendly approach. Therefore, there is great interest in finding better strategies for PET bioconversion and recycling through engineering robust enzymes and microbial strains for its degradation, uptake and assimilation. This project will seek to use Synthetic Biology approaches to develop a platform for bioremediation of contaminated environments, for example the removal and assimilation of plastic derived breakdown products. This will provide novel approaches as a means of decontamination and environmental regeneration.

Implementation of the bioremediation concept as proposed will ultimately require demonstration of safety in field trials, full engagement with regulatory authorities, and early and ongoing attention to responsible research and innovation. To develop the idea, we will commit time and effort to anticipating regulatory requirements, sustainability considerations, and societal aspects including potential societal concerns.

Anthropogenic impact upon the environment is among the biggest existential threats to humanity. Along with global warming, water and land contamination collectively threaten, food security, habitation, and the global economy. Contamination of the natural environment with xenobiotics (e.g., with heavy metals, plastics, halogenated compounds etc) causes significant challenges in terms of containment and remediation. In these polluted environments microbial communities have been shown to evolve and adapt to grow in the presence of xenobiotics by resistance, decomposition and/or assimilation of the foreign substance. These native organisms offer potential direct nature-based solutions themselves, via the use of microbial organism-based bioremediation and enhancement of plant growth promoting properties. However, competition with the resident microbiota and environmental challenges can severally hinder the persistence of the introduced species and lead to limited modification of the indigenous community. Many of the genes required for environmental bioremediation (such as heavy metal resistance cassettes) form part of the bacterial accessory genome and have been acquired through horizontal gene transfer (HGT) mediated by mobile genetic elements. Conjugative plasmids offer the potential to engineer microbiomes in situ by transferring the genes of interest (via HGT) into species already resident in the microbiome, thus overcoming issues of limited persistence of introduced strains.

This project will seek to use Synthetic Biology approaches to develop a conjugative plasmid-based platform for bioremediation of contaminated environments. Specifically, by engineering plasmid-encoded degradative and catabolic biosynthetic pathways for bioremediation, for example the removal and assimilation of plastic derived breakdown products. This will provide novel approaches as a means of decontamination and environmental regeneration.