Safety evaluation of the food enzyme glucan 1,4-α-maltotetraohydrolase from Bacillus licheniformis (strain DP-Dzr46)

Abstract

The food enzyme glucan 1,4-α-maltotetraohydrolase (4-α-d-glucan maltotetraohydrolase, EC 3.2.1.60) is produced with a genetically modified Bacillus licheniformis strain DP-Dzr46 by Danisco US Inc. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and recombinant DNA. The glucan 1,4-α-maltotetraohydrolase food enzyme is intended to be used in baking processes. Based on the maximum use levels, dietary exposure to the food enzyme–Total Organic Solids (TOS) was estimated to be up to 0.405 mg TOS/kg body weight (bw) per day in European populations. The toxicity studies were carried out with another glucan 1,4-α-maltotetraohydrolase from B. licheniformis (strain DP-Dzf24). The Panel considered this food enzyme as a suitable substitute to be used in the toxicological studies, because it derives from the same recipient strain as strain DP-Dzr46, the location of the inserts is comparable, no partial inserts were present and the production methods are comparable. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level (NOAEL) at the highest dose of 94 mg TOS/kg bw per day that, compared with the estimated dietary exposure, results in a sufficiently high margin of exposure of at least 232. Similarity of the amino acid sequence to those of known allergens was searched and none was found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.