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pH Control of the production of recombinant glucose oxidase in Aspergillus nidulans
Author(s) -
Luque R.,
Orejas M.,
Perotti N.I.,
Ramón D.,
Lucca M.E.
Publication year - 2004
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2004.02322.x
Subject(s) - aspergillus nidulans , xylose , aspergillus niger , glucose oxidase , biochemistry , inducer , oxidase test , enzyme , biology , chemistry , complementation , heterologous , gene , fermentation , mutant , phenotype
Aims: 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. Methods and 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. Significance and Impact of the Study: 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.