pH control of the production of recombinant glucose oxidase in Aspergillus nidulans.
OBJECTIVE
Recombinant Aspergillus nidulans sVAL040, capable of synthesizing and secreting glucose oxidase derived from Aspergillus niger was used to study the influence of pH and carbon source on enzyme production.


RESULTS
Glucose oxidase gene (goxC) was expressed under transcriptional regulation by using the promoter of A. nidulans xlnB gene (encoding an acidic xylanase). A maximum specific glucose oxidase activity of approx. 10 U mg(-1) protein and a maximum volumetric productivity of 29.9 U l(-1) h(-1) were obtained at pH 5.5, after 80 h of growth by using xylose as inducer. Enzyme volumetric productivity increased when xylans were used instead of xylose; however, specific glucose oxidase activity did not differ significantly.


CONCLUSIONS
Specific GOX activity obtained at pH 5.5 are two to three times more than those previously described for goxC multicopy transformants of A. nidulans. Xylans were a more powerful inducer than xylose although fungal growth was lower when the polymers were used.


CONCLUSIONS
The obtained results by using xlnB promoter in A. nidulans could be useful in improving heterologous enzyme production by using genetic- and process-engineering strategies.
Luque
R
R
Planta Piloto de Procesos Industriales Microbiológicos PROIMI, Consejo Nacional de Investigaciones Científicas y Técnicas, Tucumán, Argentina.
Orejas
M
M
Perotti
N I
NI
Ramón
D
D
Lucca
M E
ME
D001233:Aspergillus nidulans / Q000201:enzymology*; D002455:Cell Division; D003470:Culture Media; D005632:Fructose / Q000378:metabolism; D005949:Glucose Oxidase / Q000096:biosynthesis*; D006863:Hydrogen-Ion Concentration; D014990:Xylans / Q000378:metabolism; D014994:Xylose / Q000378:metabolism
D003470:Culture Media; D014990:Xylans; D005632:Fructose; D014994:Xylose; D005949:Glucose Oxidase