| Summary: | Glycerol is a main by-product of the biodiesel industry and thus has drawn attention as substrate for the production of high-value chemicals by microorganisms. Compared to sugars like glucose, it offers some advantages since it holds a higher degree of reduction. However, many industrial microbes have poor ability to use it. For instance, the eukaryotic model Saccharomyces cerevisiae has to be engineered to efficiently metabolize it. In contrast, the filamentous fungus Ashbya gossypii, used for industrial riboflavin production, owns a natural ability to utilize glycerol. Still, its potential to exploit it remains unexplored. Therefore, in this study, an engineered A. gossypii strain, harnessed for improved riboflavin production1 and orotic acid biosynthesis, was further modified for improved glycerol consumption. This strategy revealed to be efficient in improving the consumption profile, the glycerol-dependent hyperosmotic tolerance and the yield of biomass production of A. gossypii strains while effectively maintaining the metabolic flux towards increased riboflavin production and orotic acid accumulation/excretion. Furthermore, optimization of process conditions in shake-flask and bioreactor were performed to enhance the production of these compounds. Thus, we present A. gossypii as a suitable host for the production of high-value chemicals, particularly orotic acid and riboflavin, from glycerol feedstocks. 1Silva et al, J Biotechnol 193;37-40.
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