Safety evaluation of the food enzyme chitinase from Streptomyces violaceoruber (strain pChi).

ABSTRACT: The food enzyme, a chitinase (EC 3.2.1.14), is produced with the genetically modified Streptomyces violaceoruber strain pChi by Nagase. No information was provided regarding the presence of antimicrobial resistance genes in the production strain, other than that used in the genetic modification. The chitinase is intended to be used in baking processes. Based on the maximum use levels recommended, dietary exposure to the food enzyme-total organic solids (TOS) was estimated on the basis of individual data from the EFSA Comprehensive European Food Consumption Database. The exposure estimate is up to 0.829 mg TOS/kg body weight per day in European populations. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-days oral toxicity study in rats. The Panel identified a no observed adverse effect level at the highest dose tested of 791 mg TOS/kg body weight, which, compared with the dietary exposure, results in margin of exposure of at least 1,171. Similarity of the amino acid sequence to those of known allergens was searched and no matches were found. The Panel considered that there are no indications for food allergic reactions to this chitinase. Based on the data provided and the derived margin of exposure, the Panel concluded that the food enzyme chitinase produced with the genetically modified S. violaceoruber strain pChi does not give rise to safety concerns arising from the toxicological studies and the production process under the intended conditions of use. The CEP Panel was unable to conclude on the absence of viable cells and DNA from the genetically modified production strain in the food enzyme, for which uncertainty remains on the possible presence of gene(s) conferring antimicrobial resistance.

SUBMITTER: EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) 

PROVIDER: S-EPMC7009069 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature