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Safety evaluation of the food enzyme chymosin from the genetically modified Kluyveromyces lactis strain CHY

on the Wiley Online Library


Panel members at the time of adoption

Claude Lambré, José Manuel Barat Baviera, Claudia Bolognesi, Pier Sandro Cocconcelli, Riccardo Crebelli, David Michael Gott, Konrad Grob, Evgenia Lampi, Marcel Mengelers, Alicja Mortensen, Gilles Rivière, Inger‐Lise Steffensen, Christina Tlustos, Henk Van Loveren, Laurence Vernis, Holger Zorn and Andrew Chesson.

Legal notice: The full opinion will be published in accordance with Article 12 of Regulation (EC) No 1331/2008 once the decision on confidentiality will be received from the European Commission.


The food enzyme chymosin (EC is produced with the genetically modified Kluyveromyces lactis strain CHY by DSM Food Specialties B.V. It is intended to be used in milk processing for cheese production and for production of fermented milk products. Dietary exposure was estimated to be up to 0.69 mg total organic solids (TOS)/kg body weight (bw) per day in European populations. The production strain contains multiple copies of known antimicrobial resistance genes and consequently, it does not fully fulfil the requirements for the qualified presumption of safety (QPS) approach to safety assessment. However, considering the absence of viable cells and DNA from the production organism in the food enzyme, this is not considered to be a risk. As no other concerns arising from the microbial source and its subsequent genetic modification or from the manufacturing process have been identified, the Panel considered that toxicological tests were not needed for the assessment of this food enzyme. Similarity of the amino acid sequence of the food enzyme to those of known allergens was searched and four matches were found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure, although unlikely, cannot be excluded, particularly for individuals sensitised to cedar pollen allergens. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.