Safety and efficacy of l‐tryptophan produced by fermentation with Escherichia coli KCCM 80152 for all animal species

nutritional additive, amino acids, L-tryptophan, safety, efficacy, Escherichia coli KCCM 80152
First published in the EFSA Journal
2 May 2019
3 April 2019
Scientific Opinion


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‐tryptophan produced by fermentation using Escherichia coli KCCM 80152 when used as nutritional additive in feed and water for drinking for all animal species. The production strain and its recombinant DNA were not detected in the additive. l‐Tryptophan, manufactured by fermentation with E. coli KCCM 80152, does not give rise to any safety concern with regard to the genetic modification of the production strain. The use of l‐tryptophan produced using E. coli KCCM 80152 in supplementing feed to compensate for tryptophan deficiency in feedingstuffs is safe for non‐ruminant target species. Using unprotected forms of tryptophan in ruminants can be a risk. The use of l‐tryptophan produced by fermentation using E. coli KCCM 80152 in animal feed presents no concerns to consumers of animal products. Due to the content of endotoxins, the additive poses a risk for persons handling the additive when exposed by inhalation. The additive is not considered irritant for skin or eyes and is not considered a skin sensitiser. The additive under assessment is safe for the environment. The additive under assessment is regarded as an effective source of the amino acid l‐tryptophan for all non‐ruminant species. If l‐tryptophan is intended for use in ruminants, it should be protected from ruminal degradation.

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(5):5695
Question Number
On request from
European Commission
Relevant information or parts of this scientific output have been blackened in accordance with the European Commission decision on the confidentiality requests formulated by the applicant. The full output has been shared with the European Commission, EU Member States and the applicant.