A preparation of endo-1,4-beta-xylanase (EC 3.2.1.8) produced from Trichoderma reesei CBS 146249

In the current application, an authorisation is sought under Article 4(1) for a preparation of endo-1,4-beta-xylanase (EC 3.2.1.8) produced from Trichoderma reesei CBS 146249, under the category/functional group 4 (a) “zootechnical additives”/“digestibility enhancers” according to Annex I of Regulation (EC) No 1831/2003, for all poultry species, pigs for fattening, suckling and weaned piglets and all minor porcine species.
According to the Applicant, the active substance of the feed additive is endo-1,4-beta-xylanase (EC 3.2.1.8), produced by a fermentation of a genetically modified strain of Trichoderma reesei (CBS 146249).
The feed additive is intended to be marketed as solid and liquid formulations, having a guaranteed minimum activity of endo-1,4-beta-xylanase of 40000 U/g and 8000 U/g, depending on the formulation.
The activity of endo-1,4-beta-xylanase is expressed in xylanase units (U), where one activity unit (U) of endo-1,4-beta-xylanase is the amount of enzyme which releases 0.48 μmol of reducing sugar (xylose equivalent) per minute from wheat arabinoxylan at pH 4.2 and 50ºC.
The feed additive is intended to be incorporated directly into compound feed or through premixtures to obtain a minimum xylanase activity of 625 U and 2000 U/kg compound feed, depending on animal species.
For the determination of endo-1,4-beta-xylanase activity in the feed additive, premixtures and compound feed, the Applicant proposed a single-laboratory validated and further verified colorimetric method, based on measuring of water soluble dyed fragments released by the action of endo-1,4-beta-xylanase on commercially available azurine cross-linked arabinoxylan substrate (Xylazyme^® tablets). This method has been evaluated and further recommended by the EURL for official control for the determination of endo-1,4-beta-xylanase activity in the feed additive, premixtures and compound feed in the frame of the previous dossier from the same Applicant (as the current application) for basically identical product (FAD-2011-0030), which was further authorised as a feed additive. The above-mentioned method has been evaluated and the product was authorised with the original definition of the enzyme activity. However, later, the Applicant requested the change of the original definition to the one specified in the current dossier and has proven the equivalency of both definitions.
In the frame of the current application, the Applicant demonstrated applicability of the above-mentioned method in batch-to-batch analysis for the determination of the enzyme activity in the feed additive and in the frame of stability and homogeneity studies of the enzyme in compound feed, containing the feed additive. The Applicant did not present any new studies for the determination of endo-1,4-beta-xylanase in premixtures, containing the feed additive of the current application. However, based on the corresponding data for premixtures from the previous application for basically identical product (FAD-2011-0030), the EURL considers that the method is also applicable for the determination of the enzyme activity in premixtures in the frame of the current application.
Based on the performance characteristics and available data, the EURL recommends for official control the single-laboratory validated and further verified colorimetric method, based on measuring of water soluble dyed fragments released by the action of endo-1,4-beta-xylanase on azurine cross-linked wheat arabinoxylan, to determine the activity of endo-1,4-beta-xylanase in the feed additive, premixtures and compound feed.
Further testing or validation of the methods to be performed through the consortium of National Reference Laboratories as specified by Article 10 (Commission Regulation (EC) No 378/2005, as last amended by Regulation (EU) 2015/1761) is not considered necessary.