Fig. 2: Heterologous gene expression and metabolite production in Aspergillus niger.
From: New colours for old in the blue-cheese fungus Penicillium roqueforti
a Colony phenotype and extracts from culture filtrates. The A. niger parental strain P2 (control) as well as the strains overexpressing the P. roqueforti alb1 gene, either alone (alb1OE) or in combination with ayg1 (alb1OE/ayg1OE), were incubated for 60 h on Aspergillus minimal medium and pictures were taken from top and bottom view. In parallel, strains were incubated for 40 h in liquid Aspergillus minimal medium and culture filtrate extracts are shown (Extract). b HPLC analysis of culture filtrate extracts shown in a. Exact-mass determination confirmed that the alb1OE strain produces the naphthopyrone YWA1, which is converted into 1,3,6,8-tetrahydroxynaphthalene in the alb1OE/ayg1OE strain.
