What's My Story: Biosystem Engineering

Dr. John Sheppard

It was obvious to anyone that John Sheppard wanted to be an engineer when he built himself an original Mini Cooper at age 15 from junkyard pieces. But he loved biology too—the ways biological systems work together. Add those proclivities to a long and successful career and you end up with a professor of brewing at North Carolina State University.

Bioprocess Engineering: a conglomerate of mathematics, biology and industrial design, and includes the design and study of fermentors.

John Sheppard's Mini CooperWhen did you discover you wanted to be an engineer?

My father was an electrical engineer. He could fix anything around the house. I wanted to be like him. I built a car when I was 15. We lived in the country in Ontario and I needed a way to get to town to see my friends. I got the body of a 1961 Austin Mini from a wrecker and an engine somewhere else and made it drivable. When I turned 16 and got my license, I had a car ready to go. I still drive an original Mini. You’ll see it in the parking lot.

What did you study in school?

I was really interested in biology as much as engineering. I looked for a college that combined the two and found one at the University of Guelph near home. I found that I really liked university life much more than high school. The things we were learning were no longer simplified, this was the real stuff, and we were able to design real things. I liked applying engineering principles to solve biological problems. I got the feeling that I could be a productive member of society during college. Coming out of high school, I didn’t have that feeling.

Where did your career take you?

After obtaining my masters degree, I ended up working for the National Research Council in the Bioenergy Division, looking at ways of getting energy out of biomass. After this program was terminated, I was transferred to the new Biotechnology Research Institute in Montreal. I was looking at how to control single-celled organisms like bacteria and yeast. There are two things that control a cell, the genetic code on the inside and the environment on the outside. Instead of relying on genetic modification of cells, I prefer to work with the native organism and create an environment that modifies their behavior to make useful products more efficiently. 

After eight years of that, school looked pretty good again. I took a leave of absence and got my PhD in chemical engineering at McGill University. Instead of going back to work for the government, I thought I’d give academia a try. There was a job opening in Biosystems Engineering at McGill. That’s where I started researching brewing. I was interested in yeast fermentation and how engineers could better control the metabolism of the yeast cultures to make more consistent beer. 

What are you excited about in your job right now?

In the last couple of years, it looks as though a great brewing mystery has been solved. In general, there are two types of beer: ale and lager. Ale is the oldest type of beer and is fermented at warm temperatures while lager beers are fermented at cold temperatures. Lagers—from Budweiser to Heineken—sound old as the hills because they are now the mainstay of the commercial brewing industry, but the practice of making lager beer didn’t start until about 400 years ago. Researchers have been using genetics to track down the origins of the yeast that can do its fermentation in cool temperatures. After searching all over Europe, a genetic relative of the current lager species turned up growing on tree bark at the tip of South America.

How did the yeast cross the ocean, you ask? Like everything else in those days, probably by boat.

Once Columbus found the route to the new world, trade exploded between the two hemispheres. Researchers suspect that wood from the yeast-infected trees was made into barrels bound for Europe. Another possibility is that a South American fruit fly attracted to the boat by the spoiled food on board, stowed away, and brought the yeast to Europe in its gut. This is exciting, thinking about how the modern brewing industry has evolved based on the biodiversity of the cells we depend upon. I respect the fact that brewing depends on native populations of yeasts. I enjoy working with them.

- By Lucy Laffitte

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