Project title: Optimizing Diatom Metabolism for Bioplastic Production with supervisors Supervisors: Martina Doblin and Raffaela Abbriano Burke.
After finishing a Bachelor and a Master in Biotechnology at the University of Natural Resources and Life Sciences Vienna and working on projects involving the microbial conversion of hydrogen and carbon dioxide into platform chemicals and biogas, I commenced my PhD at the University of Technology in 2019.
The widespread use of petroleum-derived plastics and their accumulation in the marine environment has attracted increasing scientific concern as many synthetic plastic polymers are resistant to degradation, persistent, and potentially detrimental to wildlife and human health. Polyhydroxyalkanoates (PHAs) are naturally-occurring biodegradable polyesters that exhibit a range of physical properties suitable for commercial applications, making PHAs an attractive substitute for conventional plastic polymers derived from fossil fuels.
This study will provide important fundamental research to determine whether microalga metabolism, specifically in the diatom Phaeodactylum tricornutum, can be engineered to optimize the photosynthetic production of PHA polymers that can be used to manufacture biodegradable plastics.
While there are heterotrophic archaea and bacteria as well as autotrophic cyanobacteria that are native producers of PHA, producing PHA in diatoms is of interest because a well-developed molecular toolkit makes them amenable to genetic manipulation. These organisms also have a large pool of available precursors that suggest their metabolism can be shifted towards PHA production, potentially exceeding the production capabilities of native producers.
This project aims at the introduction of a heterologous pathway for PHA biosynthesis contained on a self-replicating episome into the diatom Phaeodactylum tricornutum. Furthermore, the optimization of PHA production adjusting growth conditions, manipulation of native metabolism and transgene expression are scopes of this project.
This project is significant because it will provide the basis for sustainably producing biodegradable plastics, substituting petrochemical based materials that have a large environmental footprint, with the benefit of CO2. Additionally, this work will provide knowhow about the potential of heterologous production of high value products in P. tricornutum based on the same precursor.