Enhanced Production of Itaconic Acid through Development of Transformed Fungal Strains of .

Metabolic engineering with a high-yielding mutant, AN37, was performed to enhance the production of itaconic acid (IA). Reportedly, the gene cluster for IA biosynthesis is composed of four genes: (regulator), (mitochondrial transporter), (cis-aconitate decarboxylase), and (membrane transporter). By overexpressing each gene of the IA gene cluster in AN37 transformed by the restriction enzyme-mediated integration method, several transformants showing high productivity of IA were successfully obtained. One of the AN37/ transformants could produce a very high amount of IA (75 g/l) in shake-flask cultivations, showing an average of 5% higher IA titer compared with the high-yielding control strain. Notably, in the case of the transformants, a maximal increase of 18.3% in IA production was observed relative to the control strain under the identical fermentation conditions. Meanwhile, the overexpression of and genes showed no significant improvements in IA production. In summary, the overexpressed -aconitate decarboxylase (CAD) and putative membrane transporter (MFS) appeared to have positive influences on the enhanced IA productivity of the respective transformant. The maximal increases of 13.6~18.3% in IA productivity of the transformed strains should be noted, since the parallel mother strain used in this study is indeed a very high-performance mutant that has been obtained through intensive rational screening programs in our laboratory.