# Safety evaluation of the food enzyme pullulanase from the non‐genetically modified Klebsiella pneumoniae strain AE‐PUL

**Authors:** Holger Zorn, José Manuel Barat Baviera, Claudia Bolognesi, Francesco Catania, Gabriele Gadermaier, Ralf Greiner, Baltasar Mayo, Alicja Mortensen, Yrjö Henrik Roos, Marize L. M. Solano, Monika Sramkova, Henk Van Loveren, Laurence Vernis, Silvia Peluso, Magdalena Andryszkiewicz, Daniele Cavanna, Ana Criado, Cristina Fernàndez‐Fraguas, Yi Liu

PMC · DOI: 10.2903/j.efsa.2025.9332 · EFSA Journal · 2025-05-19

## TL;DR

This study evaluates the safety of a food enzyme produced by a non-genetically modified bacteria, concluding it is safe under intended use conditions.

## Contribution

The novelty lies in the safety evaluation of a food enzyme from a known pathogen, confirming its safety for use in food manufacturing.

## Key findings

- Genotoxicity tests showed no safety concerns for the food enzyme.
- The margin of exposure was found to be at least 1653, indicating a safe level of use.
- Potential allergenicity was identified, but no adverse effects were observed in toxicity studies.

## Abstract

The food enzyme pullulanase (pullulan 6‐α‐glucanohydrolase, EC 3.2.1.41) is produced by Amano Enzymes Inc. with the non‐genetically modified Klebsiella pneumoniae strain AE‐PUL, a known human pathogen. The food enzyme is free from viable cells of the production organism and its DNA. The food enzyme is intended to be used in 10 food manufacturing processes. Since residual amounts of food enzyme—total organic solids (TOS) are removed in two processes, dietary exposure was calculated only for the remaining eight food manufacturing processes. It was estimated to be up to 0.075 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic 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 of 0 124 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, results in a margin of exposure of at least 1653. A search for the homology of the amino acid sequence of the pullulanase to known allergens was made and matches with two food allergens were found. The Panel considered that a risk of allergic reactions upon dietary exposure to this food enzyme cannot be excluded. 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.

## Linked entities

- **Proteins:** LDA (limit dextrinase)
- **Species:** Klebsiella pneumoniae (taxon 573)

## Full-text entities

- **Diseases:** toxicity (MESH:D064420), allergic reactions (MESH:D004342)
- **Species:** Rattus norvegicus (brown rat, species) [taxon 10116], Homo sapiens (human, species) [taxon 9606], Klebsiella pneumoniae (species) [taxon 573]

## Full text

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## References

14 references — full list in the complete paper: https://tomesphere.com/paper/PMC12086373/full.md

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Source: https://tomesphere.com/paper/PMC12086373