Safety evaluation of the food enzyme isoamylase from a Dyella sp. strain

food enzyme, Isoamylase, Glycogen α‐1,6-glucanohydrolase, EC, Pseudomonas amyloderamosa, Dyella sp
First published in the EFSA Journal
1 octobre 2020
9 septembre 2020
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 isoamylase (glycogen α‐1,6‐glucanohydrolase, EC is produced with Dyella sp. by Hayashibara Co. Ltd. Whole genome sequence analysis of the production strain identified a sequence with high homology with a gene conferring resistance to an antimicrobial, which may confer cross‐resistance to a critically important antimicrobial, as defined by the World Health Organisation. This is a concern, since DNA from the production strain was detected in the food enzyme. The isoamylase food enzyme is intended to be used in starch processing for the production of various starch hydrolysates. Since residual amounts of total organic solids are removed by the purification steps applied during the production of saccharides from starch, dietary exposure was not calculated. The batch used for toxicological testing was not sufficiently characterised; therefore, the toxicological data provided were not considered. 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 of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood for this to occur is considered to be low. Overall, the Panel cannot conclude on the safety of the food enzyme isoamylase produced with Dyella sp.

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, Claude Lambré, Evgenia Lampi, Marcel Mengelers, 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(10):6250
Question Number
On request from
European Commission