Safety and efficacy of a feed additive consisting of l‐cystine produced with Escherichia coli DSM 34232 for all animal species (Wacker Chemie AG)

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of l‐cystine produced with a genetically modified strain of Escherichia coli K‐12 (DSM 34232) as a sensory feed additive (functional group: flavouring compounds) for all animal species. The l‐cystine manufactured by fermentation with E. coli DSM 34232 did not give rise to any safety concern regarding the genetic modification of the production strain. No viable cells or DNA of the production strain were detected in the final product. The use of l‐cystine produced by fermentation with E. coli DSM 34232 in feed was considered safe for the target species when supplemented at concentrations up to 25 mg/kg complete feed. The FEEDAP Panel considered that the use of l‐cystine in animal nutrition is safe for the consumers of products from animals receiving the additive, and for the environment. Regarding user safety, the additive was not considered a skin and eye irritant, nor a skin sensitiser. As l‐cystine is used in food as a flavouring compound, it is expected that it can provide a similar function in feed and no further demonstration of efficacy is necessary.