Hydrocarbons are essential base chemicals as energy carriers and starting materials for chemical manufacture. So-called fatty acid photodecarboxylases (FAPs) represent interesting catalysts for the conversion of natural fatty acids into hydrocarbons thereby giving access to alkanes from renewable feedstock. Today, however, only few FAPs are known. In the current study we report a new FAP from the marine organism Micractinium conductrix (McFAP). In contrast to currently known FAPs McFAP exhibits high catalytic activity towards short and medium fatty acids. Recombinant expression and basic biochemical characterisation of this new member of the FAP family is reported.

Hydrocarbon synthesis from (waste)oils enabled by a cascade of lipase-catalysed hydrolysis and decarboxylase-catalysed decarboxylation has become an active area of research en route to alternative, biobased fuels. However, Poor substrate transport efficiency is a major issue causing low reaction rates. This study focused on a protein self-assembly strategy based on SpyTag/SpyCatcher to overcome diffusion limitations. For this, two fusion proteins, TLL-Linker-SpyCatcher based on the lipase from Thermomyces lanuginosus and CvFAP-Linker-SpyTag based on the fatty acid photodecarboxylase from Chlorella variabilis were designed. A covalent multi-enzyme complex (TLL-CvFAP) was formed spontaneously by self-assembly of each enzyme. The effects of temperature, pH and molar ratio of self-assembled components on assembly efficiency were investigated. The results showed that the multi-enzyme complex TLL-CvFAP reached about 60% after 12 h of assembly, and the enzyme activity of the multienzyme complex was increased by about 50% compared to that of the corresponding non-assembled enzymes. Under optimized conditions 10 mM soybean oil were converted into 25 mM of the corresponding hydrocarbons, suggesting a good potential of biofuel synthesis.