Production and characterisation of monoclonal antibodies for the quantification of potentially allergenic xylanase from Aspergillus niger

Abstract

Xylanase from Aspergillus niger (ANX) is widely used in bakeries as a processing aid since it stabilises and improves dough quality. An association between allergic symptoms among bakery workers and sensitisation to ANX has been reported, indicating that this enzyme is an occupational allergen. The presence of ANX in dough improvers and semi-finished goods is often hidden due to incomplete and unclear labelling. The quantification of microbial enzymes in these products is necessary and the determination of the actual concentration of ANX in workplaces is therefore essential to assess the occupational risk. To this purpose we have developed and characterised monoclonal antibodies to ANX. The monoclonal antibodies do not show any cross-reaction with other commonly used microbial enzymes, and they allow the detection of ANX in complex mixtures by ELISA inhibition assays down to the concentration limit of approximately 10 µg kg⁻¹. These mAbs are a valuable tool to detect and quantify ANX and to investigate its allergenic potential in the workplace.

Keywords:

• Endo-1,4-beta-xylanase
• Aspergillus niger
• monoclonal antibodies
• quantification
• wheat flour
• dough improvers
• occupational allergy

Acknowledgements

This work was financed by grants from the Fondazione Cariverona (Project Title: ‘Development of Study Models for Safety Assessment of Enzymes Used in Cereal Flours’), Istituto Nazionale Assicurazione contro gli Infortuni sul Lavoro (INAIL) and Novartis.