Xylanase from Trichoderma reesei CBS 114044 (4a8i) returns for pigs for fattening, laying hens and minor poultry after the authorisation lapsed in 2021: activity in BXU from birch xylan, in feed — azurine-crosslinked wheat arabinoxylan substrate, pH 5.3 and 50 °C
Commission Implementing Regulation (EU) 2025/1386, published on 16 July 2025, authorises until 5 August 2035 a preparation of endo-1,4-beta-xylanase (EC 3.2.1.8) from the genetically modified strain Trichoderma reesei CBS 114044 (ECONASE XT, holder: AB Enzymes Finland Oy) as a digestibility enhancer for pigs for fattening, laying hens and minor poultry species. For these species the authorisation expired on 24 November 2021 because the renewal application was not submitted one year before the deadline — a new application was needed. EFSA (opinion of 18 September 2024) found no viable cells or DNA of the strain in the product and judged the additive safe; all forms are considered respiratory sensitisers.
- Methods in the annex (the EURL considered the conclusions of the earlier assessment still valid): in the additive and premixtures — colorimetric method with birch xylan as substrate, pH 5.3 and 50 °C; in compound feed — colorimetric method with azurine-crosslinked wheat arabinoxylan, pH 5.3 and 50 °C. 1 BXU is the amount of enzyme that releases 1 nmol of reducing sugars (as xylose) per second from birch xylan under these conditions. The annex requires min. 160 000 BXU/g for the solid and liquid forms, although according to EFSA five forms are marketed: 160 000 (XT 25 L and XT 25), 400 000 (XT L), 800 000 (XT 5 P) and 4 000 000 BXU/g (XT P).
- Purity (EFSA opinion, five batches of each form): total coliforms < 1 CFU/g, Salmonella and E. coli absent in 25 g, yeasts and filamentous fungi < 10² CFU/g; lead, mercury, cadmium, arsenic, aflatoxins, fumonisins, ochratoxin A, sterigmatocystin, zearalenone, T-2, HT-2 below the LOQ — except deoxynivalenol at 50–250 µg/kg in the solid forms (wheat flour as carrier). Trichodermin in three batches below the LOD of 2.5 µg/kg; peptaibols were not analysed — EFSA relies on the absence of antimicrobial activity.
- Properties: XT 25 and XT 5 P dust-free (0 mg/m³, Stauber-Heubach), XT P 22–93 mg/m³, particles < 63 µm up to 40.1 %. After 24 months at 25 °C and 30 °C, 97 and 82 % of activity remains (XT 25 L), but only 73 and 63 % (XT P). No losses on pelleting up to 95 °C; in a pig premixture after 6 months 87–93 %; in chicken feed after 3 months 95 % (mash) and 76 % (pelleted). Homogeneity: CV 6.8 % (XT 25), 8.4–12.4 % for the liquid form sprayed on pellets.
- Minimum levels in the annex (BXU/kg complete feed): pigs for fattening 20 000, laying hens and laying minor poultry 12 000, other minor poultry 8 000; no maximum. The applicant proposed 24 000 BXU/kg for laying minor poultry — EFSA extrapolated the conclusions from laying hens (12 000). Solid forms: EFSA could not assess eye irritation or skin sensitisation, hence respiratory, skin and eye protection; liquid forms — respiratory protection.