Scientific Opinion on the safety and efficacy of L-tryptophan, technically pure, produced by Escherichia coli strains DSM 25084, KCCM 11132P or SARI12091203 for all animal species based on a dossier submitted by AMAC EEIG

The product L-tryptophan is a nutritional feed additive produced by fermentation using one of three strains of Escherichia coli. L-Tryptophan produced by E. coli SARI12091203 could not be assessed because the data submitted did not permit the identity and safety of the strain, and the purity of the additive, to be determined. The EFSA Panel on Additives and Products or Substance used in Animal Feed (FEEDAP) could not conclude on the safety of this product for target animals, for consumers, users and the environment. Strain KCCM 11132P is genetically modified, but its product gives no cause for concern on GM grounds because no recombinant DNA or live bacteria were detected. L-Tryptophan produced by E. coli KCCM 11132P or E. coli DSM 25084 is safe for non-ruminant target species when supplemented to diets in appropriate amounts, but should not be given to ruminants in an unprotected form because of the formation of skatole (3-methylindole) during ruminal fermentation. L-Tryptophan produced by E. coli KCCM 11132P or E. coli DSM 25084 contains low concentrations of 1,1′-ethylidene-bis-L-tryptophan and 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid and is safe for the consumer of animal products. The level of endotoxins present in the products of E. coli KCCM 11132P or E. coli DSM 25084 and its possible dusting potential indicate an inhalation risk for the user. In the absence of data on the potential for dermal sensitisation it is concluded that such potential may exist. No other concerns for user safety (inhalation toxicity, skin and eyes irritation) regarding the L-tryptophan produced by E. coli DSM 25084 were identified. The use of the product L-tryptophan produced by E. coli KCCM 11132P or E. coli DSM 25084 in animal nutrition does not pose a risk to the environment. The products under application are efficacious sources of the amino acid L-tryptophan for animal nutrition.