Products from the bioeconomy play an important role in a sustainable future, but are dependent on cheap and available biomass as a carbon source. The availability of sustainable biomass, though, is limited by the arable area of our planet. Even by deforestation and setting up new agricultural area, we cannot provide enough arable land for both biomass for the bioindustry and food crops to solve the problem of world hunger. So if we hardly manage to feed the population, how can we guarantee the supply of biomass for other biotechnological products?

The best option would be to use CO₂ from the air to form products. Recent technological advancements made it possible to convert CO₂ into methanol with a great efficieny. This is where our project comes in. To take a step forward in solving this complex problem, we wanted to develop our E. coli that converts methanol to glycogen.

Glycogen is a sugar polymer that is safe to handle and can be easily converted into glucose. Therefore, it can then be used as a carbon source for almost all existing bioprocessess since those rely on sugar. Our project has the potential to make the bioindustry independent from plants and instead use CO₂ from the air. Thereby not only methanol is opened up as a new carbon source but also the CO₂ level in the atmosphere is reduced. We connect the bioeconomy with advanced technologies of CO₂ fixation.

We decided to use the newly developed, ATP-neutral Methanol Condensation Cycle^[1] to enable E. coli to take up methanol. Glycogen accumulation was achieved by combining knocking out one degradation enzyme and overexpressing the synthesis genes.

The main advantage of our product is that it addresses the problem in various ways. Not only can the potential of methanol as a carbon source be exploited but also the surplus CO₂ in the atmosphere is utilized. It has to be considered as well that by fixing the CO₂ technically, non-arable areas like deserts can be used.

Furthermore the problem is approached by mounting large areas of energy crops.

Another potential solution to this global problem are farming of algae, where simple carbon compounds using CO₂ and sunlight are produced. However, the technical process of fixing CO₂ that precedes our process, for example through the company sunfire, is far more efficient also compared to plants. The efficency of energy that is converted into chemical energy is about 80 times higher than the conversion of CO₂ to biomass through plants and even 18 times higher than the maximal efficieny natural photosynthesis can theoretically have.^[2]

References

1. ↑ Bogorad IW, Chen CT, Theisen MK, Wu TY, Schlenz AR, Lam AT, Liao JC. Building carbon-carbon bonds using a biocatalytic methanol condensation cycle. Proc Natl Acad Sci U S A. 2014 Nov 11;111(45):15928-33. doi: 10.1073/pnas.1413470111. Epub 2014 Oct 29. PubMed PMID: 25355907; PubMed Central PMCID: PMC4234558.
2. ↑ Die natürliche Photosynthese: Ihre Effizienz und die Konsequenzen - Hartmut Michel