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 the safety for the target animals, consumer, user and the environment and on the efficacy of a concentrated liquid l-lysine (base, minimum 50%) and a l-lysine monohydrochloride (HCl, minimum 99%) produced by fermentation with a genetically modified strain of Corynebacterium glutamicum (KCTC 12307BP). Both forms of l-lysine are intended to be used in feed for all animal species and categories. Neither the production strain nor its recombinant DNA were detected in the final products. The additives do not pose any safety concern associated with the genetic modification of the production strain. Concentrated liquid l-lysine (base) and l-lysine HCl produced by the strain C. glutamicumKCTC 12307BP do not represent a risk for the target species, for the consumer, for the user and for the environment. l-Lysine HCl and concentrated liquid l-lysine (base) are considered to be efficacious sources of the essential amino acid l-lysine for non-ruminant animal species. For the supplemental l-lysine to be as efficacious in ruminants as in non-ruminant species, it would require protection against degradation in the rumen.