Cloning and heterologous expression of the extracellular alpha-galactosidase from Aspergillus fumigatus in Aspergillus sojae under the control of gpdA promoter

Aspergillus fumigatus is highly pathogenic especially for immunocompromised people however it can efficiently produce many industrially important enzymes. The gene coding α-galactosidase enzyme (aglB) of A. fumigatus IMI 385708 has been cloned onto pAN52-4 fungal expression vector and expressed in a GRAS organism, Aspergillus sojae ATCC11906 under the control of constitutive glyceraldehyde-3-phosphate dehydrogenase (gpdA) promoter. pAN52-4 fungal expression system allowed high level α-galactosidase production in media with simple sugar glucose as the sole carbon source and without a requirement for an inducer with a yield of 2.45 U/ml which is nearly 3-fold higher than the yield obtained from A. fumigatus grown in locust bean gum containing medium.