초록
<P><B>Background</B></P><P>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 <I>Aspergillus terreus</I>. 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 <I>A. terreus</I> strains to increase itaconic acid production.</P><P><B>Results</B></P><P>In this study, the genes closely related to itaconic acid production, including <I>cadA</I>, <I>mfsA</I>, <I>mttA</I>, ATEG_09969, <I>gpdA</I>, ATEG_01954, <I>acoA</I>, mt<I>-pfk</I>A and <I>citA</I>, were identified and overexpressed in an industrial <I>A. terreus</I> strain respectively. Overexpression of the genes <I>cadA</I> (<I>cis</I>-aconitate decarboxylase) and <I>mfsA</I> (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.</P><P><B>Conclusions</B></P><P>Itaconic acid production could be improved through genetic engineering of the industrially used <I>A. terreus</I> strain. We have identified some important genes such as <I>cadA</I> and <I>mfsA</I>, 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.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s12934-014-0119-y) contains supplementary material, which is available to authorized users.</P>