In-depth analysis of the Aspergillus niger glucoamylase (glaA) promoter performance using high-throughput screening and controlled bioreactor cultivation techniques.

An in-depth characterization of the Aspergillus niger glucoamylase (glaA) promoter performance was carried out on defined medium employing multi-well high-throughput screening as well as controlled batch and fed-batch bioreactor culture techniques with GFP as a fluorescent reporter protein. A variety of metabolizable carbon substrates and non-metabolizable analogs were screened with regard to their effect on the glaA expression system. The results clearly demonstrate that only starch and its hydrolytic products, including glucose, act as inducers.

In situ multi-wavelength fluorescence spectroscopy as effective tool to simultaneously monitor spore germination, metabolic activity and quantitative protein production in recombinant Aspergillus niger fed-batch cultures.

The production of a mutant green fluorescent protein (S65TGFP), controlled by the maltose inducible glucoamylase promoter, was followed in situ in fed-batch cultures of recombinant Aspergillus niger using multi-wavelength fluorescence spectroscopy. Disturbance of quantitative product analysis by interfering fluorescence signals was resolved by using a set of defined combinations of excitation and emission wavelengths (lambda(ex)/lambda(em)). This technique resulted in excellent linearity between on-line signal and off-line determined S65TGFP concentrations.

GlaA promoter controlled production of a mutant green fluorescent protein (S65T) by recombinant aspergillus niger during growth on defined medium in batch and fed-batch cultures.

The first successful expression of the Aequorea victoria green fluorescent protein (GFP) gene in Aspergillus niger is described. When the wild-type GFP gene was expressed in A. niger, neither the fluorescence nor the full translation product of the wtGFP gene was detectable.