Safety and efficacy of l‐threonine produced by fermentation with Corynebacterium glutamicum ■■■■■ for all animal species

nutritional additive, amino acid, L-threonine, safety, efficacy, genetically modified microorganism
First published in the EFSA Journal
1 March 2019
22 January 2019
Scientific Opinion

Relevant information or parts of this scientific output have been blackened in accordance with the confidentiality requests formulated by the applicant pending a decision thereon by the European Commission. The full output has been shared with the European Commission, EU Member States and the applicant. The blackening will be subject to review once the decision on the confidentiality requests is adopted by the European Commission.


Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on l‐threonine produced by fermentation with Corynebacterium glutamicum ■■■■■ when used as nutritional additive in feed and water for drinking for all animal species and categories. The product under assessment is l‐threonine produced by fermentation with a genetically modified strain of C. glutamicum (■■■■■). The production strain and its recombinant DNA were not detected in the additive. The product l‐threonine, manufactured by fermentation with C. glutamicum, ■■■■■ does not give rise to any safety concern with regard to the production strain. l‐Threonine produced using C. glutamicum■■■■■ is considered safe for the target species. The FEEDAP Panel has concerns regarding the safety of the simultaneous oral administration of l‐threonine via water for drinking and feed. l‐Threonine produced using C. glutamicum ■■■■■ is safe for the consumer. The additive is not a skin or eye irritant and is not a skin sensitiser. Although the workers can be exposed by inhalation, the results of an acute inhalation study showed that risk of adverse effects by inhalation is low. l‐Threonine produced using C. glutamicum ■■■■■ is safe for the environment. The product under assessment is considered an efficacious source of the amino acid l‐threonine for all animal species. For l‐threonine to be as efficacious in ruminants as in non‐ruminant species, it requires protection against degradation in the rumen.

Panel members at the time of adoption

Giovanna Azimonti, Vasileios Bampidis, Maria de Lourdes Bastos, Henrik Christensen, Birgit Dusemund, Maryline Kouba, Mojca Kos Durjava, Marta López‐Alonso, Secundino López Puente, Francesca Marcon, Baltasar Mayo, Alena Pechová, Mariana Petkova, Fernando Ramos, Yolanda Sanz, Roberto Edoardo Villa and Ruud Woutersen.
Panel on Additives and Products or Substances used in Animal Feed
feedap [at]
EFSA Journal 2019;17(3):5603
Question Number
On request from
European Commission