Safety of l‐threonine produced by fermentation with Escherichia coli CGMCC 11473 as a feed additive for all animal species

Nutritional additive, amino acid, l‐threonine, safety, all animal species
First published in the EFSA Journal
6. November 2019
4. Oktober 2019
Scientific Opinion

Legal notice: 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.


The l‐threonine under assessment is produced by fermentation with a genetically modified strain of Escherichia coli and it is intended to be used as a nutritional additive for all animal species. In 2017 the Panel on Additives and products or Substances used in Animal Feed (FEEDAP) of EFSA issued an opinion on the safety and efficacy of the product. In that assessment, the Panel could not conclude on the safety of the additive for the target species, consumers and the environment due to the lack of data regarding the characterisation of the production strain and the resulting product. The applicant provided additional data on the identity of the production strain, the genetic modification, the susceptibility to antibiotics and the absence of cells and recombinant DNA of the production strain in the final product. The recipient strain is safe and the genetic modification does not raise concerns. Moreover, viable cells or DNA of the production strain were not detected in the final product. With this new information the FEEDAP Panel concluded that l‐threonine produced by E. coli CGMCC 11473 is safe for the all animal species, the consumers and the environment. The FEEDAP Panel could not conclude on the potential of the additive to be irritant to skin and eyes or on the skin sensitisation potential. It was concluded that there is a risk of exposure to endotoxins by inhalation for persons handling the additive.

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(11):5885
Question Number
On request from
European Commission