Oliver Englund’s thesis identifies biotechnological pathways towards more diverse biobased building blocks

Oliver Englund Örn defended his thesis in February 2023, within STEPS work package one: green building blocks. In this interview, he highlights his main findings, and how his research can be used by other researchers and stakeholders. In his work, he gets motivated by curiosity and a desire to develop.

What did you research in your thesis?

A man, Oliver Englund Örn. Photo. — Oliver Englund Örn defended his thesis in February 2023, within STEPS work package one: green building blocks.

I performed my PhD in biotechnology focusing on microbial production of biobased plastic building blocks.

Specifically, I used Escherichia coli bacteria cells, and genetically modified them to produce aromatic and aliphatic plastic building blocks from glucose. These building blocks, or monomers, can be used to develop plastic polymers, once you recover them in a pure form from the concoction they have been produced in. I also produced the aliphatic building blocks adipic acid and 4hydroxybutyrate form biobased 1,6 hexanediol and 1,4-butanediol, respectively, with the bacteria G. oxydans. The same techniques I used can also be used to produce many other chemicals as well.

Using bacteria such as E. coli has many benefits. If you compare the process of making biobased monomers directly from sugar, you can get a HMF-molecule (5-Hydroxymethylfurfural) by a chemical process which is good, but with E. coli or other bacteria, you can change the metabolic pathway and produce a more diverse range of plastic monomers from different sugars with different efficiencies. This is also why biotechnology is such a growing area.

What are the main findings?

I could produce both protocatechuic acid and adipic acid from biobased substrates such as glucose to be among of the highest achieved concentrations reported in scientific literature. I have also worked on enzymatically degraded PBAT (polybutylene adipate terephthalate), and used similar techniques to convert the degradation products to value-added chemicals.

Did anything surprise you during your work?

Learning about the state of the plastic industry and recycling was an eye opener in many ways.

How can your research be used by stakeholders?

The aim was to provide biomass producers a way to transform their biomass, for example glucose, into plastic building blocks. Therefore, those who have available biomass or production plants to transform the biomass could benefit.

My research can also be used by other researchers who work to develop this field. Since the thesis presents similar results to other research using E. coli, it shows that the process for transforming bacteria to monomers is replicable.

Could these research results be scaled up and become a viable biobased plastics alternative?

Well, there is certainly enough research to show that this process works, and that we can produce biobased plastics that are easy to reuse or biodegrade. The main reason that it has not caught on is that it is still too expensive a process in comparison to using oil to produce plastics.

My aim as a researcher is to provide a means for the plastic industry to change, if only in a small way. But to realize that change with the current economic and political drivers I think will be hard. Yet, I do hope that more actors will see the value of investing in more sustainable techniques in the future, in spite of costs. As the research to use second generation biomass from e.g. the forest industry, develops, so can this process catch on too, and become further developed.

What drives you as a researcher?

Curiosity and a desire to develop. I also wanted to do something I could be proud of, and which could be of benefit to others, which was one of the reasons this PhD project attracted me from the start.

Download Oliver Englund Örns thesis summary: Towards sustainable plastics: Microbial production of aromatic and aliphatic building blocks from biobased feedstock and plastic hydrolysate at lu.se