High level production of itaconic acid at low pH by Ustilago maydis with fed-batch fermentation

• Published in: Bioprocess and biosystems engineering Vol. 44; no. 4; pp. 749 - 758
• Main Authors: Demir, Hatice Taşpınar, Bezirci, Emine, Becker, Johanna, Tehrani, Hamed Hosseinpour, Nikerel, Emrah, Wierck, Nick, Türker, Mustafa
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-04-2021; Springer Nature B.V
• Subjects: Acid production; Acids; Basidiomycota - chemistry; Batch culture; Biomass; Bioreactors; Biotechnology; Carbon - chemistry; Carbon content; Carbon Dioxide - chemistry; Chemistry; Chemistry and Materials Science; Environmental Engineering/Biotechnology; Fed batch; Fermentation; Food Science; Fungal Proteins - metabolism; Glucose - chemistry; Growth rate; Hydrogen-Ion Concentration; Industrial and Production Engineering; Industrial Chemistry/Chemical Engineering; Industrial Microbiology - methods; Itaconic acid; Nitrogen - chemistry; pH effects; Phosphates - chemistry; Research Paper; Substrate Specificity; Succinates - chemistry; Temperature; Temperature control; Ustilago maydis; Weak acid stress; Itaconic acid; Low pH cultivation; Fed-batch fermentation; Ustilago maydis
• ISSN: 1615-7591; 1615-7605
• DOI: 10.1007/s00449-020-02483-6

The metabolically engineered plant pathogen
Ustilago maydis
MB215 Δ
cyp3 P
etef
ria1
has been cultivated to produce more than 80 g/L itaconate in 16 L scale pH and temperature controlled fermentation, in fed-batch mode with two successive feedings. The effect of pH as well as successive rounds of feeding has been quantified via elemental balances. Volumetric itaconic acid productivity gradually decreased with successive glucose feedings with increasing itaconic titers, with nearly constant product yield. Extracellular pH was decreased from 6 down to 3.5 and the fermentation was characterized in specific uptake, production, and growth rates. Notable is that the biomass composition changes significantly from growth phase to itaconic acid production phase, carbon content increases from 42% to around 62%. Despite the gradual decrease in itaconic acid levels with decreasing pH (nearly 50% decrease in itaconic acid at pH 3.5, compared to pH 6), significant itaconate production is still observed at pH 4 (around 63 g/L). Biomass yield remained nearly constant until pH 4. Taken together, these results strongly illustrate the potential of engineered
Ustilago maydis
in itaconate production at commercial levels.