Influence of carbon and nitrogen concentration on itaconic acid production by the smut fungus Ustilago maydis

Abstract

Itaconic acid is a valuable platform compound for the production of bio‐based polymers, chemicals, and fuels. Ustilago maydis is a promising host for the production of itaconic acid from biomass‐derived substrates due to its unicellular growth pattern and its potential to utilize biomass‐derived sugar monomers and polymers. The potential of U. maydis for industrial itaconate production was assessed in pH‐controlled batch fermentations with varying medium compositions. Using 200 g/L glucose and 75 mM ammonium, 44.5 g/L of itaconate was produced at a maximum rate of 0.74 g L−1 h−1. By decreasing the substrate concentrations to 50 g/L glucose and 30 mM ammonium, a yield of 0.34 g/g (47 mol%) could be achieved. Itaconate production from xylose was also feasible. These results indicate that high itaconic acid titers can be achieved with U. maydis. However, further optimization of the biocatalyst itself through metabolic engineering is still needed in order to achieve an economically feasible process, which can be used to advance the development of a bio‐based economy.

Itaconic Acid: The Surprising Role of an Industrial Compound as a Mammalian Antimicrobial Metabolite

“…The authors of this article suggest that MfsA is a membrane transporter required for itaconic acid secretion (for more details on subcellular compartmentalization of itaconic acid biosynthesis, see Section 2). The optimization of the fermentation process using the natural itaconic acid producer Ustilago maydis only achieved, with 44.5 g · l −1 of itaconic acid, half of the production of A. terreus (57). For increasing itaconic acid yields, the kinetic parameters and the low stability of CAD enzyme need to be considered.…”

The Corn Smut Fungus Ustilago maydis as an Alternative Expression System for Biopharmaceuticals

“…1d ). Furthermore, cells are robust and well suited for bioreactors which can be grown to high densities in a short time, without loss of strain fi tness (Maassen et al 2014 ) (Fig. 1e ).…”

“…Therefore, several groups are employing it to produce bio-based platform chemicals. Aerobic fermentation of cellulosic biomass has been successfully employed for production of itaconic acid, a platform chemical for the synthesis of potential biofuels Maassen et al 2014 ). A metabolic model for optimized itaconic acid production has been developed which can eventually be helpful in reactor studies and downstream processing of broth for protein expression purposes (Voll et al 2012 ).…”

Activating Intrinsic Carbohydrate-Active Enzymes of the Smut Fungus Ustilago maydis for the Degradation of Plant Cell Wall Components

“…Commercial itaconic acid production is currently achieved biotechnologically with engineered strains of Aspergillus terreus. Although this filamentous fungus is remarkably efficient in terms of its itaconic acid yield and titer (22,23), it is worthwhile to work on alternative unicellular production organisms since they potentially enable a more efficient and controllable high-density process (24,25).…”

“…maydis exhibits filamentous growth during plant infection and colonization. However, it can also grow saprotrophically as unicellular haploid yeast and proliferates in simple medium in axenic culture with various hexoses and pentoses as a carbon source (25,38). In the yeast form, the fungus is nonpathogenic and amenable to genetic manipulation.…”