Identification of FadAB Complexes Involved in Fatty Acid β-Oxidation in and Construction of a Triacylglycerol Overproducing strain.

Oleaginous microorganisms represent possible platforms for the sustainable production of oleochemicals and biofuels due to their metabolic robustness and the possibility to be engineered. is among the narrow group of prokaryotes capable of accumulating triacylglycerol (TAG) as carbon and energy reserve. Although the pathways for TAG biosynthesis in this organism have been widely addressed, the set of genes required for their breakdown have remained elusive so far. Here, we identified and characterized three gene clusters involved in the β-oxidation of fatty acids (FA). The role of each of the three different FadAB proteins in FA catabolism was confirmed by complementation of an Δ mutant strain deficient in β-oxidation. In , the expression profile of the three gene clusters showed variation related with the stage of growth and the presence of FA in media. Flux balance analyses using a corrected version of the current metabolic model containing detailed TAG biosynthesis reactions suggested the relevance of the identified genes in the accumulation of TAG. Thus, through the construction and analysis of knockout mutant strains, we obtained an mutant that showed a 4.3-fold increase in the TAG content compared to the wild type strain grown under the same culture conditions.