Overexpression of the gene encoding alternative oxidase for enhanced glucose consumption in oxalic acid producing Aspergillus niger expressing oxaloacetate hydrolase gene

In this study, to show the availability of aoxA gene encoding AOX as a tool for metabolic engineering, we generated efficient oxalic acid (OA)-producers by genetic engineering of A. niger using aoxA gene. The OA-producing strain EOAH-1, generated by overexpression of the oxaloacetate hydrolase (EC 3.7.1.1; OAH) gene oahA in A. niger WU-2223L, produced 28 g/L OA from 30 g/L glucose during the 9-day cultivation period. Moreover, the strain EAOXOAH-1, generated by overexpression of both aoxA and oahA genes in strain WU-2223L, produced 28 g/L OA during the 7-day cultivation period. Strain EAOXOAH-1 showed higher glucose consumption rate than EOAH-1 did, indicating that overexpression of aoxA contributed to the acceleration of glucose consumption, and that the OA production period was shortened by 2 days. Thus, we clearly show that AOX gene must be an effective tool in metabolic engineering for efficient organic acids production from carbohydrates.Graphical abstract
Source: Journal of Bioscience and Bioengineering - Category: Biomedical Science Source Type: research