title: Improving itaconic acid production through genetic engineering of an industrial Aspergillus terreus strain.
abstract: BACKGROUND
  Itaconic acid, which has been declared to be one of the most promising and flexible building blocks, is currently used as monomer or co-monomer in the polymer industry, and produced commercially by Aspergillus terreus. However, the production level of itaconic acid hasn't been improved in the past 40 years, and mutagenesis is still the main strategy to improve itaconate productivity. The genetic engineering approach hasn't been applied in industrial A. terreus strains to increase itaconic acid production.
  
  
  RESULTS
  In this study, the genes closely related to itaconic acid production, including cadA, mfsA, mttA, ATEG_09969, gpdA, ATEG_01954, acoA, mt-pfkA and citA, were identified and overexpressed in an industrial A. terreus strain respectively. Overexpression of the genes cadA (cis-aconitate decarboxylase) and mfsA (Major Facilitator Superfamily Transporter) enhanced the itaconate production level by 9.4% and 5.1% in shake flasks respectively. Overexpression of other genes showed varied effects on itaconate production. The titers of other organic acids were affected by the introduced genes to different extent.
  
  
  CONCLUSIONS
  Itaconic acid production could be improved through genetic engineering of the industrially used A. terreus strain. We have identified some important genes such as cadA and mfsA, whose overexpression led to the increased itaconate productivity, and successfully developed a strategy to establish a highly efficient microbial cell factory for itaconate protuction. Our results will provide a guide for further enhancement of the itaconic acid production level through genetic engineering in future.
authors.forename: Xuenian
authors.initials: X
authors.lastname: Huang
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Lu
authors.forename: Yueming
authors.initials: Y
authors.lastname: Li
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No, 189 Songling Road, Qingdao 266101, China. lijj@qibebt.ac.cn.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Li
mesh_terms: D001230:Aspergillus / Q000235:genetics* / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000235:genetics; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D005110:Extracellular Space / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D005800:Genes, Fungal; D005818:Genetic Engineering / Q000379:methods*; D005947:Glucose / Q000378:metabolism; D007218:Industrial Microbiology; D010865:Pilot Projects; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D013386:Succinates / Q000378:metabolism*; D013997:Time Factors; D014170:Transformation, Genetic
chemical_list: D005656:Fungal Proteins; D013386:Succinates; D005947:Glucose; C005229:itaconic acid