Behind the PhD degree: Ruizhe Pei

“I wish I had another two years.” One of the first PhD candidates that started working for the Biopolymers from Water theme cannot get enough of his research. He’s a man with a plan – who discovered his love for teaching and microscopy. This is the story of Ruizhe Pei.

The science behind the person, and the person behind the science

Static liveliness

Ruizhe’s inherent passion for the inconceivably small kept him chasing the unknown. “I’ve always been amazed by the liveliness we cannot even see. Take a plant, for instance – it seems static to us, but it’s far from that, complex systems with parts that move at unimaginable speeds.” Inside it’s an immense traffic chaos of molecules that float all over the place for networks and pathways that we have yet to discover.

Biology was not more than a logical choice of study, were it not for Ruizhe’s parents. “My parents always left me free in my choices, though they always nudged me a little in a direction they thought would benefit me. And so I ended up studying the engineering side of the field. And I’m glad to have done so.”

After his studies in Wageningen and a brief chase for different positions in Wetsus, Ruizhe was offered a job in the biopolymers from water theme. A position that he did not apply for, as that one was already given to Ángel. Instead, research dedicated to processing the PHA bioplastic after production was his goal. “’No way’ was my first response. I’m picky. But I did end up going for it, as I got to give it my own twist.”

Quite the mix

And since little infrastructure was there to start with, Ruizhe’s creativity and input were welcome. “I went all over the place, to Van Hall across the street, and to Paques in Balk to get my experiments going. But in the end, we decided to invest in our own equipment. It was an amazing opportunity to start from scratch. I did get some experiments in before the order, but now we could really get going.”

The production of PHA was already relatively well known, but recovery was an understudied part of the process. “So, half of my PhD I dedicated to understanding this step. How do we get the biopolymers from the bacteria without the PHA breaking down in the process? About the degradation, little was known, and you can imagine that losing material on the side of a test tube is negligible. However, on a larger scale with a larger amount of materials, more polymer loss can be expected, and that can determine the viability of the process” Quality and quantity are key. “I witnessed it at multiple levels – from our lab to our large reactor and even a 4 m3 reactor operated by Paques in Leeuwarden wastewater treatment plant.”

“But I really want to see what I’m working on too. So, I spent quite some time staring down the microscope. It gave me great insight into the accumulation of PHA in bacteria. With a chemical analysis, you can only see how much you get from certain cells in total, not at the different cells individually.” Since Ruizhe worked with sewage sludge bacteria, it is quite the mix. “With microscopy, I understood where the biopolymers formed, giving fundamental insight into our unique method of making PHA. And it allowed me to fulfill the desire of seeing these tiny processes in action.”

Climbing gym

“I wish I had another two years. The beauty of Wetsus is that you can do research that can be used in collaborating companies, and you get a real insight into what they want to know. But I also learned how great it is to work with children and students. To give them insights in the science. It is fulfilling to see them grow in knowledge over time, and it is already great to share what I know.”

“Now I’ve worked from a top-down perspective. I would love to continue from the bottom up too. I realized that I want to continue working in academia, so I will definitely go for a postdoc. One key thing to look for in my next job is that it is in a city with a climbing gym. It must be in a city with a climbing gym. Climbing, too, is a passion I have uncovered during my PhD.”