Safety evaluation of the food enzyme β‐galactosidase from the genetically modified Escherichia coli NCIMB 30325

food enzyme, β‐galactosidase, β‐D‐galactoside galactohydrolase, EC, Escherichia coli, genetically modified microorganism
First published in the EFSA Journal
23 January 2020
12 December 2019
Scientific Opinion

Note: 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 is a β‐galactosidase (β‐D‐galactoside galactohydrolase; EC produced with the genetically modified Escherichia coli strain NCIMB 30325 by Clasado Ingredients Ltd. The β‐galactosidase encoding gene is introduced into the recipient strain of E. coli using a self‐replicating plasmid which also contains a gene, which confers resistance to an antibiotic listed as a critically important antimicrobial. This gene was detected in the food enzyme. The absence of viable cells of the production strain in the food enzyme was not demonstrated. The food enzyme is intended to be used only for the production of a mixture of galacto‐oligosaccharides (GOS). Genotoxicity tests did not raise a safety concern. Subchronic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level at the highest dose tested of 900 mg total organic solids (TOS)/kg body weight (bw) per day. Similarity of the amino acid sequence to those of known allergens was searched and no match was found. The Panel considered that under the intended conditions of use the risk for allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood is considered low. Given the risk associated with the presence of antibiotic resistance gene in the food enzyme and the lack of data showing the absence of viable cells, the Panel concludes that the use of β‐galactosidase produced with the genetically modified E. coli NCIMB 30325 cannot be considered safe.

Panel members at the time of adoption

José Manuel Barat Baviera, Claudia Bolognesi, Andrew Chesson, Pier Sandro Cocconcelli, Riccardo Crebelli, David Michael Gott, Konrad Grob, Evgenia Lampi, Alicja Mortensen, Gilles Rivière, Vittorio Silano, Inger‐Lise Steffensen, Christina Tlustos, Henk Van Loveren, Laurence Vernis and Holger Zorn.
Panel on Food Contact Materials, Enzymes and Processing Aids
fip [at]
EFSA Journal 2020;18(1):5977
Question Number
On request from
European Commission