The safety of a Kluyveromyces lactis strain lineage for enzyme production

Kluyveromyces lactis is broadly considered as a safe yeast in food and a suitable organism for the production of food enzymes. The K. lactis enzyme production strains of DSM are used to produce a variety of enzymes, for example beta-galactosidase (lactase), chymosin and esterase. All of these production strains are derived from the same lineage, meaning they all originate from the same ancestor strain after classical mutagenesis and/or genetic engineering. Four different enzyme preparations produced with strains within this lineage were toxicologically tested. These enzyme preparations were nontoxic in repeated-dose oral toxicity studies performed in rats and were non-genotoxic in vitro. These studies confirm the safety of the DSM K. lactis strains as a production platform for food enzymes, as well as the safety of the genetic modifications made to these strains through genetic engineering or classical mutagenesis. The outcome of the toxicity studies can be extended to other enzyme preparations produced by any strain from this lineage through read across. Therefore, no new toxicity studies are required for the safety evaluation, as long as the modifications made do not raise safety concerns. Consequently, this approach is in line with the public ambition to reduce animal toxicity studies.