Opinion of the Scientific Panel on Additives and Products or Substances used in Animal Feed and of the Scientific Panel on Genetically Modified Organisms on the safety and efficacy of the enzyme preparation Natuphos® (3-phytase) produced by Aspergillus niger

The additive Natuphos® is a preparation of 3-phytase currently authorised when produced by Aspergillus niger strain FTU-8 for use in piglets, pigs for fattening, sows, chickens for fattening, laying hens and turkeys for fattening (E 1600). The applicant is now seeking authorisation for a change of the production strain to the genetically modified Aspergillus niger NPH54 and for the use of new liquid and solid formulations with a double concentration compared to that of the preparation currently authorised. The production strain Aspergillus niger NPH54 is derived from a parental line that has been used extensively for the production of industrial enzymes. A cDNA gene for 3-phytase from Aspergillus niger NRRL3135 was introduced into Aspergillus niger GAM-53 so that no additional DNA was retained. The introduced gene was targeted to characterised chromosomal locations where multiple copies of the naturally occurring glucoamylase gene were already present. Natuphos phytase is produced by submerged fermentation of the production strain, and the enzyme is secreted into the culture medium. The enzyme is recovered by a combination of solid/liquid separation, followed by concentration of the liquid fraction using a UF-membrane. The production process generates an enzyme preparation from which the production micro-organism has been removed. SDS-PAGE and the analysis of pH and temperature profiles were used to show that the 3-phytase enzyme produced by Aspergillus niger NPH54 was similar to the enzyme in Natuphos® 5000, approved for use as a feed additive. The production strain Aspergillus niger NPH54 and the 3-phytase produced from it raise no new safety concern. From the data provided on composition, formulation and stability of the new concentrated formulations, it is not expected that the change in concentration will have adverse consequences for efficacy and safety. Since the genes encoding for the active substance (3-phytase) are the same as for the already authorised Natuphos, the FEEDAP Panel does not expect efficacy of the product to be modified in comparison with the authorised (and assessed) product. However, efficacy has not been previously evaluated for turkeys. Therefore, the data for this target species has been assessed by the FEEDAP Panel. From the data presented in seven trials, the FEEDAP Panel concluded that the efficacy of Natuphos® has been demonstrated for turkeys for fattening at the minimum recommended dose of 250 FTU kg-1 feedingstuffs. Since the new production strain differs from the one currently authorised, tolerance studies in the target species are required. These have demonstrated that Natuphos® NPH54 is safe for chickens for fattening, piglets and pigs for fattening. However, there is not enough evidence to conclude on the safety of this enzyme preparation for laying hens, turkeys and sows due to the short duration of the studies provided. The product is not mutagenic and does not show toxic effects on the 90-day study with relevance to consumer safety. There was no evidence of skin and eye irritation or adverse effects occurring during inhalation when this product was used. As no sensitization study was provided, the product should be regarded as a potential skin sensitizer. The active ingredient is a naturally occurring 3-phytase and is consequently of no environmental concern.