Safety and efficacy of a feed additive consisting of l‐tryptophan (produced with Escherichia coli CGMCC 7.460) for all animal species (Kempex Holland B.V.)

Abstract Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of the feed additive consisting of l‐tryptophan produced by fermentation with Escherichia coli CGMCC 7.460 when used as a nutritional additive in feed and water for drinking for all animal species and categories. The production strain is not genetically modified. Viable cells of the production strain were not detected in the final additive. The additive does not give rise to any safety concern regarding the production strain. The use of l‐tryptophan (≥ 98%) produced with E. coli CGMCC 7.460 to supplement feed is safe for non‐ruminant species. There may be a risk for an increased production of toxic metabolites when unprotected tryptophan is used in ruminants. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) has concerns on the safety of the simultaneous oral administration of l‐tryptophan via water for drinking and feed due to possible amino acid imbalances and hygienic reasons. The use of l‐tryptophan produced with E. coli CGMCC 7.460 in animal nutrition raises no safety concerns to consumers of animal products and to the environment. In the absence of data, the FEEDAP Panel cannot conclude on the potential of the additive to be irritant to skin or eyes, or on its potential to be a dermal sensitiser. The endotoxin activity of the additive in combination with the high dusting potential may represent a risk of exposure by inhalation to endotoxins for users. The additive l‐tryptophan is regarded as an effective source of the amino acid l‐tryptophan for all non‐ruminant species. To be as efficacious in ruminants as in non‐ruminants, it should be protected from ruminal degradation.