Abstract
The discovery that hydrocarbons present in our environment can be of natural origin, and not only due to human pollution, is very recent. It turns out that microorganisms (cyanobacteria) are capable of naturally producing considerable quantities of hydrocarbons (pentadecane, heptadecane, nonadecene, etc., several hundred million tonnes a year!), while others use and degrade them (hydrocarbon respiration) in a virtuous biological cycle. We're beginning to understand the enzymatic reactions involved in these hydrocarbon syntheses(Science, 2010). These alkanes are derived from fatty aldehydes that undergo an oxidative deformylation reaction catalyzed by non-heme iron monooxygenases(JACS, 2013).
These discoveries have led many laboratories to use the corresponding genes and couple them with other metabolic modifications (synthetic biology) to build microorganisms as simple asE. coli capable of mass-producing small alkanes, propane or nonane(Nature Communications, 2014; Nature, 2013). Medium-chain alkenes, such as undecene, can also be produced(PNAS, 2014). The discovery of a specific enzyme for the oxidative decarboxylation of fatty acids makes it possible to produce such terminal alkenes. Synthetic biology has also been used extensively for the production of isoprene, a very important precursor for industry (synthetic gum, lubricants, adhesives, etc.). These new reactions join those already well known from the metabolism of methanogens, exploited for biomethane production.
