Construction and physiological characterization of glyceraldehyde-3-phosphate dehydrogenase overproducing transformants of Aspergillus nidulans

Abstract

The construction and characterization of glyceraldehyde-3-phosphate-dehydrogenase (GPD) overproducing transformants of Aspergillus nidulans and their behaviour in acetate-limited continuous cultures and glucose-grown batch cultures are described. The A. nidulans acetamidase deletion strain MH1277 was transformed with the homologous gpdA gene on a vector with the homologous acetamidase-gene (amdS) as a selection marker. Transformant A1 contains about nine integrated copies of the gpdA gene, and shows a proportional gene-dosage GPD production of about 22% of the total soluble cell protein. Compared to the wild-type MH1277, A1 has higher growth yields and reaches higher specific growth rates on both acetate and glucose, which could be due to the key position of GPD in glycolysis and gluconeogenesis.