Safety evaluation of a lactase enzyme preparation derived from Kluyveromyces lactis

Food Chem Toxicol. 2000 Aug;38(8):671-7. doi: 10.1016/s0278-6915(00)00053-3.


Neutralact(R), the DSM brand name of a lactase enzyme preparation, obtained from a homologous rDNA strain of Kluyveromyces lactis, was subjected to a series of toxicological tests to document the safety for use as a processing aid in the dairy industry. The enzyme preparation was examined for subacute oral toxicity and mutagenic potential. As a result of these tests, no evidence of oral toxicity, mutagenicity or clastogenicity was found. Administration of the lactase enzyme preparation at doses of 500, 3000 and 10,000 mg/kg body weight/day for 28 days did not induce noticeable signs of toxicity. The no-observed-adverse-effect level (NOAEL) of the enzyme preparation in the acute toxicity study was 10,000 mg/kg body weight/day (equivalent to 114,000 NL units/kg body weight/day). It can be concluded that no safety concerns were identified in the studies conducted with this lactase enzyme preparation derived from Kluyveromyces lactis under controlled fermentation conditions.

MeSH terms

  • Animals
  • Chromosome Aberrations
  • Clinical Chemistry Tests
  • Female
  • Hematologic Tests
  • Humans
  • Kluyveromyces / enzymology*
  • Lactase
  • Lymphocytes / drug effects
  • Male
  • Microsomes, Liver / drug effects
  • Microsomes, Liver / metabolism
  • Mutagenicity Tests
  • Mutagens / toxicity*
  • No-Observed-Adverse-Effect Level
  • Rats
  • Rats, Wistar
  • Salmonella typhimurium / drug effects
  • Salmonella typhimurium / genetics
  • beta-Galactosidase / metabolism
  • beta-Galactosidase / toxicity*


  • Mutagens
  • Lactase
  • beta-Galactosidase