“With MaxSynBio we are world class!”

Interview with Tobias Erb about artificial photosynthesis and the research network on synthetic biology

May 11, 2020

Not only engineers but also biologists and chemists are faced with the question of whether to improve what already exists or to invent something completely new. When it comes to synthetic biology, researchers are pursuing both approaches. Tobias Erb from the Max Planck Institute for Terrestrial Microbiology in Marburg wants to better understand photosynthesis in the chloroplasts of plants and reproduce it in his laboratory. He and his team have developed a platform with which photosynthesis can be carried out in tiny droplets. In the following interview, he explains what he intends to do with these semi-artificial chloroplasts and what role the MaxSynBio network plays in this.

Tobias Erb, Leader of the Department Biochemistry and Synthetic Biology of Microbial Metabolism at the Max Planck Institute for Terrestrial Microbiology.

What exactly do these droplets consist of?

Tobias Erb: Simply put, they are tiny water bubbles in an oil solution. It’s like mixing oil with water – only you don’t get such small bubbles of uniform size.

Do the droplets have internal membranes similar to those of natural chloroplasts?

We have not yet reached that stage. But we do intend to achieve an internal three-dimensional membrane structure. This would allow us to substantially increase the surface area and increase the yields of the reactions taking place in the droplets.

Why do you want to develop artificial chloroplasts at all? Wouldn’t it be easier to optimize the natural ones?

Natural chloroplasts are the result of billions of years of evolution. Nature is indeed quite good at improving its inventions. But completely new inventions are generally avoided because the risk of failure is high.

In contrast, with our system we can always start from scratch and try out completely new synthesis pathways. In doing so, we may find solutions that nature has not yet come up with. But of course, the optimization of natural chloroplasts can also provide important insights.

Tobacco’s solar power plant: One of up to 100 chloroplasts from the cell of a tobacco leaf. Its interior is filled with stacks of flat membrane discs (thread-like structures) that contain the molecular machinery responsible for photosynthesis. Like mitochondria, chloroplasts have their own genome (light-colored areas).

What are important prerequisites for your research?

An important prerequisite for synthetic biology is networks in which we work together across disciplines and with which we can break completely new ground. With MaxSynBio, the Max Planck Society has established a highly successful network that the rest of the world looks up to. It’s like the national team, where you can select the best players from the clubs and thus build up a powerful squad. But unlike in football, we really are world class with our MaxSynBio team!

What tasks could the droplets perform in the future?

First of all, they are a huge gain for basic research. At present, if you want to study photosynthesis and the role of a particular enzyme, for example, you must first create the corresponding mutation in the plant and then cultivate it. This is complicated and takes time. With our platform, we can generate thousands of droplets within seconds. We could investigate a different scientific question in each of them. This naturally makes research faster and more cost effective.

What applications could you imagine?

One highly important aspect is the binding of carbon dioxide. Artificial chloroplasts could help us to produce substances faster, more cost-effectively, and in a more environmentally friendly, sustainable way than before. Think of white genetic engineering, for example: Many substances are currently produced with genetically modified micro-organisms. However, this is still rather ineffective because such organisms – whether yeast or bacterial cells – use only part of their resources to produce the desired substance. The rest is spent for its own growth and reproduction. But our artificial chloroplasts do not have to reproduce. They can put all their energy into producing material.

Which substances could be produced?

For example, we have already synthesized glycolate from carbon dioxide in our droplets. This is a starting material for many other more complex molecules, such as, the antibiotic erythromycin that can be produced from glycolate. We can also modify our platform to produce terpenes. These are precursors to important fragrances and vitamins used in the cosmetics and food industry.

If we succeed in extracting carbon dioxide from the atmosphere as a valuable raw material with artificial photosynthesis systems, we can help overcome the climate crisis.

Interview: Harald Rösch

 

Other Interesting Articles

Go to Editor View