Fully Funded PhD Project: Microbial Indicators of Plastic Pollution

The ecological impacts of the eight million tonnes of plastic entering our oceans each year is now easy to witness, with the guts of animals being clogged by plastic detritus. Far harder to quantify however, is the impact of poorly visible waste such as microplastics and xenobiotic chemicals that leach from plastic products. Plasticizers such as bisphenol A (BPA) impact the reproduction and development of aquatic animals at environmentally relevant concentrations. However, quantification of environmentally safe or acceptable concentrations of plastic additives in environmental samples remains a contentious issue. We seek to address this problem of significant global relevance by devising novel molecular indicators of freshwater health by assessment of the abundance of microbial molecular markers associated with plastic contamination and degradation rates in the environment. We will capitalise on the data generated by a major survey of the diversity and composition of biofilm bacterial communities in hundreds of stream throughout New Zealand to isolate and characterise bacteria, and bacterial genes that are prevalent in sites impacted by plastic pollution. We will explore the presence and abundance of these organisms and genes as potential novel indicators of plastic pollution.In addition to testing their use as biomarkers of plastic pollution, the isolation and identification of putative xenobiotic degrading bacteria provides a plethora of opportunities for the later development of novel treatment systems for the biological removal of plastic waste.

Our project aims and outputs are to:
1. Confirm the abundance of putative plastic degrading bacteria, or associated genes as a reliable indicator of the presence and toxic potential of plastic pollution in New Zealand waterways. We will develop and test novel microbial indicators to track the fate of bioavailable plastic associated compounds as they journey down our waterways, into the open ocean.
2. Isolate and culture putative plastic degrading bacteria in our laboratory and test these organisms ability to degrade a range of plastic-associated compounds under a broad range of conditions. With this knowledge we seek to develop novel microbiological approaches that can be used to maximise the degradation of plastics and plastic additives in both natural environments and engineered settings.