<i>Ustilago Rabenhorstiana</i>—An Alternative Natural Itaconic Acid Producer

• Main Authors: Susan Krull, Malin Lünsmann, Ulf Prüße, Anja Kuenz
• Format: Article
• Language: English
• Published: MDPI AG 2020-01-01
• Series: Fermentation
• Subjects: <i>ustilago</i>; itaconic acid; process improvement; lignocellulosic feedstock
• Online Access: https://www.mdpi.com/2311-5637/6/1/4

Itaconic acid is an industrial produced chemical by the sensitive filamentous fungus <i>Aspergillus terreus</i> and can replace petrochemical-based monomers for polymer industry. To produce itaconic acid with alternative renewable substrates, such as lignocellulosic based hydrolysates, a robust microorganism is needed due to varying compositions and impurities. Itaconic acid producing basidiomycetous yeasts of the family <i>Ustilaginaceae</i> provide this required characteristic and the species <i>Ustilago rabenhorstiana</i> was examined in this study. By an optimization of media components, process parameters, and a fed-batch mode with glucose the final titer increased from maximum 33.3 g&#183;L^&#8722;1 in shake flasks to 50.3 g&#183;L^&#8722;1 in a bioreactor. Moreover, itaconic acid was produced from different sugar monomers based on renewable feedstocks by <i>U. rabenhorstiana</i> and the robustness against weak acids as sugar degradation products was confirmed. Based on these findings, <i>U. rabenhorstiana</i> has a high potential as alternative natural itaconic acid producer besides the well-known <i>U. maydis</i> and <i>A. terreus</i>.