Carbon dioxide in a circular economy

Lignite-fired power plant that pollutes the air

Carbon dioxide (CO2) emission is a massive problem for our climate; this is well-known. We urgently need measures to prevent earth from the big collapse. Where do we find them? Biotechnology offers some interesting solutions.

In order to decelerate climate change the reduction of greenhouse gas emissions by at least 40% of 1990 levels would be necessary by 2030 according to the EU Paris Agreement

How can this ambitious goal be achieved? The EU strategy developed several solutions such as the EU’s emission trading system that regulates power stations and manufacturing plants. National emission targets aim at tackling emission sectors such as agriculture, transport, buildings or waste management. Another target is to reduce car emissions, which is a clear order towards automobile industry.

Make a virtue of necessity

What if there is a to make real use out of CO2 and create a recycling process? The biotechnological approach aims at creating value from this greenhouse gas. There are some microorganisms that can utilize CO2 in their metabolism and help biotechnologists to produce, for example, bio-based and biodegradable natural polymers. A well-known biopolymer is PHA (Polyhydroxyalkanoates), which is UV- and temperature stable, shows good resistance to moisture and provides a barrier for aroma compounds. For that reason, it is a popular packaging material. Another potential application field is the use as a degradable human implant material. Currently, more than 30,000 metric tons of this material are produced annually by using sugars or oils as a substrate.

acib’s tiny CO2-guzzlers

acib has a couple of organisms that enjoy consuming CO2: For example, on the one hand, a highly sophisticated strain of cyanobacteria is able to grow without sugars or oil but with only light and CO2 in a photobioreactor. Cyanobacteria are doing photosynthesis and acib modified the strain for the simultaneous generation of PHA. On the other, there is a bacterium, Cupriavidus necator, that is able to use CO2 together with H2 for further PHA production. In future applications, H2 can be provided by electrolysis of water by using excess of electric energy for example.

The way to large scale application

Currently, both approaches are validated at lab scale and the cyanobacteria technology has even been proved in a relevant environment. The first steps have been done but there is still a long way until implementation.

Picture credits: Pixabay