0000000000014949
AUTHOR
D. Ramón
An ITS-RFLP method to identify black Aspergillus isolates responsible for OTA contamination in grapes and wine
Ochratoxigenic mycobiota in grapes from representative wine regions in Valencia was identified. Black aspergilli were predominant among the different Aspergillus spp. isolated. Restriction digestion analysis of the ITS products was tested as a rapid method to identify isolates of black Aspergillus species from grapes. Restriction endonuclease digestion of the ITS products using the endonucleases HhaI, NlaIII and RsaI, distinguished five types of restriction fragment length polymorphism (RFLP) corresponding to Aspergillus niger, Aspergillus tubingensis, Aspergillus carbonarius and Aspergillus aculeatus species. In addition, a new RFLP type in the A. niger aggregate was identified. The fragme…
pH control of the production of recombinant glucose oxidase in Aspergillus nidulans.
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 o…