Safety and efficacy of l‐threonine produced by fermentation using Escherichia coli CGMCC 7.232 for all animal species

nutritional additives, amino acids and their salts and analogues, L-threonine, safety, efficacy, genetically modified microorganisms
First published in the EFSA Journal
25 October 2018
2 October 2018
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.


The product subject of this assessment is l‐threonine produced by fermentation with a genetically modified strain of Escherichia coli (CGMCC 7.232). It is intended to be used in feed and water for drinking for all animal species and categories. The production strain and its recombinant DNA were not detected in the additive. The product l‐threonine, manufactured by fermentation with E. coli CGMCC 7.232, does not raise any safety concern with regard to the genetic modification of the production strain. l‐Threonine produced using E. coli CGMCC 7.232 is considered safe for the target species. The FEEDAP Panel has concerns regarding the safety of the simultaneous administration of l‐threonine via water for drinking and feed. l‐Threonine produced using E. coli CGMCC 7.232 is safe for the consumer. In absence of data, the FEEDAP Panel cannot conclude on the potential of the additive to be irritant to skin and eyes or to be a skin sensitiser. There is a risk from the inhalation exposure to endotoxins for persons handling the additive. l‐Threonine produced using E. coli CGMCC 7.232 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 2018;16(10):5458
Question Number
On request from
European Commission