Strain Design of Ashbya gossypii for Single-Cell Oil Production

Abstract

ABSTRACTSingle-cell oil (SCO) represents a sustainable alternative for the oil industry. Accordingly, the identification of microorganisms with either higher lipidogenic ability or novel capacities for the transformation of raw materials constitutes a major challenge for the field of oil biotechnology. With this in mind, here, we were prompted to address the lipidogenic profile of the filamentous hemiascomyceteAshbya gossypii, which is currently used for the microbial production of vitamins. We found thatA. gossypiimostly accumulates unsaturated fatty acids (FAs), with more than 50% of the total FA content corresponding to oleic acid. In addition, we engineeredA. gossypiistrains both lacking the beta-oxidation pathway and also providing ATP-citrate lyase (ACL) activity to block the degradation of FA and to increase the cytosolic acetyl-coenzyme A (CoA) content, respectively. The lipidogenic profile of the newly developed strains demonstrates that the mere elimination of the beta-oxidation pathway inA. gossypiitriggers a significant increase in lipid accumulation that can reach 70% of cell dry weight. The use ofA. gossypiias a novel and robust tool for the production of added-value oils is further discussed.