PseudoProKo - Pseudomonas putida - a platform for liquid hydrocarbon production

Considering the depletion of fossil fuels, it is essential to further develop the efficient utilization of renewable resources. In bioindustrial processes, microbial production platforms can be used to generate a diverse array of valuable chemicals from simple substrates. In this project we aim at the microbial conversion of domestic plant oil into higher value lipids such as fatty aldehydes, fatty alcohols, and alkanes/alkenes.

Most studies focus on a de novo approach via the fatty acid biosynthesis by fermentation of simple substrates such as glucose. In our work, an auto-displayed lipase hydrolyzes triglycerides from rapeseed oil to glycerol and free fatty acids (mainly unsaturated C16 and C18). While glycerol serves as carbon and energy source, the fatty acids are further converted intracellularly. A reduction to fatty aldehydes is achieved by introduction of a carboxylic acid reductase. Alternatively, a plant α-dioxygenase generates n-1 fatty aldehydes. The fatty aldehydes are further reduced to fatty alcohols by a variety of endogenous E. coli reductases. The overexpression or deletion of respective genes can increase or limit the alcohol formation. In a second step the fatty aldehydes can be converted to n-1 alkanes/alkenes by cyanobacterial aldehyde deformylating oxygenases.