Integrated strain- and process design enable production of 220 g L itaconic acid with .

BACKGROUND

Itaconic acid is an unsaturated, dicarboxylic acid which finds a wide range of applications in the polymer industry and as a building block for fuels, solvents and pharmaceuticals. Currently, is used for industrial production, with titers above 100 g L depending on the conditions. Besides , is also a promising itaconic acid production host due to its yeast-like morphology. Recent strain engineering efforts significantly increased the yield, titer and rate of production.

RESULTS

In this study, itaconate production by was further increased by integrated strain- and process engineering. Next-generation itaconate hyper-producing strains were generated using CRISPR/Cas9 and FLP/FRT genome editing tools for gene deletion, promoter replacement, and overexpression of genes. The handling and morphology of this engineered strain were improved by deletion of , which is part of a regulatory cascade that governs morphology and pathogenicity. These strain modifications enabled the development of an efficient fermentation process with in situ product crystallization with CaCO. This integrated approach resulted in a maximum itaconate titer of 220 g L, with a total acid titer of 248 g L, which is a significant improvement compared to best published itaconate titers reached with and with .

CONCLUSION

In this study, itaconic acid production could be enhanced significantly by morphological- and metabolic engineering in combination with process development, yielding the highest titer reported with any microorganism.