Hunting for superior microorganisms

​Designing microorganisms that synthesize natural products is one key to a sustainable future. But the production levels are often low, making biosensors a valuable asset in the hunt for cells with superior capacity.
​Modern biotechnology makes it possible to construct microorganisms that can produce almost any natural product. These microorganisms play an important part when moving towards a more sustainable generation of fuels and chemicals.

However, one problem is that initial production levels often are very low. A major challenge is therefore to turn poor producers into efficient ones.

Verena Siewers, project leader in the division of Systems and Synthetic Biology at the Department of Biology and Biological Engineering, has been working with biosensors for the past five years. This was also the topic for her Docent lecture on October 3.

– If we have a library of hundreds or thousands of different strains, it’s not possible for us to analyse them all. With metabolite sensors we can screen our samples, she explains.
– The biosensors make it possible to detect and select individual cells with superior production. They also allow for the regulation of enzyme production dependent on the metabolic state of the cell.

The work of Verena Siewers is done in yeast cells. But to design sensors, the research group adds components from other organisms, such as bacteria.

– We have been able to show that this works, but we are still in a trial and error phase. In the future we will have a general principle that shows how to modify the cell, but more systematic work is needed to get there. In five years, I believe we will have a lot of new sensors, Verena Siewers says.
– The sensors will also be better. Today, we can detect a group of chemicals, like fatty acids. But in the future it will also be possible to distinguish between, for instance, saturated and unsaturated fatty acids.

Researchers around the world are now putting effort into the search for biosensors. Verena Siewers laughs:
– When we started to work on this, in 2011, the area was still quite novel. Now there are many of us exploring this! It’s funny how ideas pop up at the same time in different research labs.

Text: Mia Malmstedt
Photo: Martina Butorac

Published: Thu 27 Oct 2016.