Safety and efficacy of Bacillus subtilis KCCM 10673P and Aspergillus oryzae KCTC 10258BP when used as a technological feed additive for all animal species
The additive consists of single strains of Bacillus subtilis and Aspergillus oryzae, to be used in combination as a technological additive (proposed functional group: Substances for the reduction of anti-nutritional factors) in feed materials for all animal species. An opinion on the two microorganisms was published previously. At this time, the safety of the B. subtilis strain for target animals, consumers, users and the environment was established, but no conclusions could be draw on the safety of the strain of A. oryzae for the target species and consumers or on the efficacy of the additive in reducing anti-nutritional factors. This opinion considers new information intended to address the identified deficiencies in the previous opinion. An extensive analytical search for secondary metabolites was made of the A. oryzae component of the additive and 15 metabolites were detected and quantified. Of the 15 metabolites, 13 occurred in ng/g additive concentrations and were considered not to be of concern. The remaining two compounds, cyclic dipeptides (2,5-diketopiperazines), were detected at concentrations up to 1.5 mg/kg. Both have been identified in a wide range of foods and beverages and there appears to be no reports of adverse reactions to such cyclic dipeptides in processed food. Consequently, none of the metabolites detected were considered likely to cause adverse effects in target animals fed treated feed material or in consumers of products derived from such animals. Data from the analysis of 18 batches of soybean before and after treatment with the two strains were presented in support of the efficacy of the additive. Two classes of anti-nutritional factors were considered; oligosaccharides of the raffinose series and trypsin inhibitor. The microbial strains in combination were able to substantially reduce the concentration of oligosaccharides and trypsin inhibitor naturally present in soybean. Other feed materials were not considered.