Itaconic acid (methylene succinic acid) is a white crystalline unsaturated C5 dicarboxylic acid. Because of its specific favorable properties and the unique structure, itaconic acid is used as... Show moreItaconic acid (methylene succinic acid) is a white crystalline unsaturated C5 dicarboxylic acid. Because of its specific favorable properties and the unique structure, itaconic acid is used as monomer or co-monomer in the manufacture of plastics, resins, synthetic fibers, paints, surfactant and elastomers etc. Besides, in 2004 it was selected by the Department of Energy in the US as one of the 12 building block chemicals that are the most interesting to be produced by industrial biotechnology. Currently itaconic acid is produced commercially by Aspergillus terreus via fungal fermentation. Due to its limited availability, the use of itaconic acid is restricted. To increase itaconic acid production levels and make it economically available, Aspergillus niger is chosen as the production host strain due to its flexibility as a production platform. Besides, A. niger accumulates organic acids on a wide range of substrat es under various environmental conditions. Most important, A. niger produces large amounts of citric acid (360 g/L) which in A. terreus actually is a precursor in the biosynthetic pathway towards itaconic acid. This thesis describes the research carried out for producing itaconic acid in A. niger, and illustrates research approaches of organic acids production in fungi in general Show less