%0 Journal Article %A Henriksen, Anne L. Santerre %A Even, Sergine %A Müller, Christian %A Punt, Peter J. %A van den Hondel, Cees A. M. J. J. %A Nielsen, Jens %T Study of the glucoamylase promoter in Aspergillus niger using green fluorescent protein %D 1999 %J Microbiology, %V 145 %N 3 %P 729-734 %@ 1465-2080 %R https://doi.org/10.1099/13500872-145-3-729 %K green fluorescent protein %K Aspergillus niger %K glucoamylase promoter %K chemostat %I Microbiology Society, %X An Aspergillus niger strain expressing a red-shifted green fluorescent protein (GFP) in the cytoplasm under the control of the glucoamylase promoter (PglaA) was characterized with respect to its physiology and morphology. Although xylose acted as a repressor carbon source during batch cultivations, PglaA-driven GFP expression by the glucoamylase promoter could be demonstrated in xylose-limited continuous cultures. In these cultivations, the xylose concentration was therefore too low to cause repression. Transient experiments initiated with a maltose pulse did not further induce red-shifted GFP production in xylose-limited continuous cultures. Maltose induction under conditions of xylose repression was microscopically observed and quantified in a flow-through chamber. Red-shifted GFP was first produced after 5 h induction. Finally the strain was characterized in glucose-limited continuous cultures, and here the area of the mycelium stained with cytoplasmic GFP increased with increasing specific growth rate, indicating that GFP can be used as a marker of cellular activity in this type of cultivation. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/13500872-145-3-729