Production of Itaconic Acid in Microorganisms Itaconic acid (2-methylidenebutanedioic acid) can be produced by microorganisms and has commercial value as a precursor of polymers, chemicals and fuels. There is interest in using microorganisms to convert biomass into useful products such as itaconic acid. The main itaconic acid producer is the fungal species Aspergillus terreus, which can produce as much as 86g/L. Image Credit: Kateryna Kon / Shutterstock.com What is itaconic acid? Itaconic acid, also known as 2-methylidenebutanedioic acid, is an unsaturated dicarbonic acid. It is considered to be a value-added product from biomass by the US Department of Energy, as it can be utilized as a precursor of polymers and chemical intermediates.