Scientific opinion on the safety and efficacy of L-tryptophan produced by Escherichia coli (FERM BP-11200) for all animal species based on a dossier submitted by Ajinomoto Eurolysine SAS

L-Tryptophan, technically pure, is a feed additive produced by a genetically modified Escherichia coli. Neither the production strain nor its recombinant DNA was detected in the final product. The final product does not raise any safety concerns with regard to the genetic modifications. The use of the additive L-tryptophan, technically pure, is safe for non-ruminant target species when supplemented in appropriate amounts to diets. Oral administration of unprotected L-tryptophan to ruminants is best avoided. L-Tryptophan will be incorporated in the protein of the body of the target animal and any potential excess will be metabolised and excreted. Considering the high purity of the product under assessment and the lack of toxicological effects at the use levels that are likely, no risks are expected for the consumer from the use of L-tryptophan, technically pure, as a feed additive. Safety is further ensured by the low level of 1,1-ethylidene-bis-L-tryptophan and analytical absence of 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid, previously seen to cause eosinophilia–myalgia syndrome in humans. The product has been shown to be non-irritant. It is not a dermal sensitiser. The results of an acute inhalation study show no evidence of significant acute toxicity by this route. Exposure of users by inhalation is likely to occur considering particle size and dusting potential. L-Tryptophan is a naturally occurring amino acid and its use in animal nutrition is not expected to be of concern for the environment. L-Tryptophan is efficacious as a supplemented amino acid to maintain or restore the adequate balance of amino acids for animal nutrition.