Short summary

Within the third module the products of carbon dioxide fixation will be used by the cell to produce the key metabolite pyruvate. Hence, it can be converted in different products. As a proof of concept we decided to introduce an isobutanol production pathway. Here we want to use and improve existing BioBricks (iGEM Team Formosa 2011/2012). The modularity of BioBricks enables the exchange of a variety of production systems. These systems can be applied on variable high value products derived from pyruvate. Pyruvate is a metabolic branching point. Hence, products like isoprene, putrescine or even antibiotics are possible candidates with industrial application.

Here you will find the results of the production of Isobutanol.

Product synthesis

The third module should benefit from the two modules before. The organism should have gained energy equivalents and reduction equivalents to generate pyruvate by binding carbon dioxide. We result in pyruvate by using the Calvin cycle. This should now be used as initial point for the product synthesis. Different products are possible, we go for a proof of concept, the isobutanol production.
When the whole system is working, the product synthesis could be changed through the modularity of BioBricks.

Isobutanol

Isobutanol is an organic compound. In IUPAC nomenclature it is called 2-methylpropan-1-ol. The advantage of this substance is that it has application fields in many industrial production sites because of this properties. For example it is used in varnish, as an gasoline additive or in paint solvents.
We think that isobutanol is a product which can be used in several ways which makes it interesting as an product of our production system.

Genetical approach

There were different genetical approaches to produce isobutanol with various organisms like cyanobacteria, Bacillus subtilis, Escherichia coli and some more. We aim to reproduce the production pipeline which was done by iGEM Team Formosa 2011 and 2012. By combining the required enzymes we will first create a production BioBrick with four enzymes. A possible enhancement could be achieved by the alcohol dehydrogenase (adhA). We aim to compare the adhA from E. coli with the adhA from Lactococcus lactis to identify the enzyme with the higher yield.