L-threonine from Escherichia coli CGMCC 7.455 (3c412) for all animal species: at least 98.5 % threonine, IEC-VIS/FLD according to EN ISO 17180, endotoxins below 300 IU/g — EFSA calculated 17 IU per working day against a threshold of 900 IU
Commission Implementing Regulation (EU) 2025/160, published on 30 January 2025, authorises until 19 February 2035 L-threonine produced with genetically modified E. coli CGMCC 7.455 as a nutritional additive (amino acids, their salts and analogues) for all animal species, in feed and in water for drinking. It is based on the EFSA opinion of 12 March 2024 (applicant: Kempex Holland B.V.).
- Specification: powder with at least 98.5 % L-threonine and at most 1 % moisture (C4H9NO3, CAS 72-19-5). Methods: identification according to the Food Chemical Codex L-threonine monograph; in the additive — ion-exchange chromatography coupled to post-column derivatisation and optical detection (IEC-VIS/FLD) according to EN ISO 17180; in premixtures EN ISO 17180 or IEC-VIS according to Regulation (EC) No 152/2009; in compound feed IEC-VIS (152/2009); in water IEC-VIS or IEC-VIS/FLD.
- EFSA data: five batches averaged 100.7 % L-threonine on an as-is basis (99.7–101.2 %), moisture and residue on ignition 0.2 % each, specific optical rotation in three batches −28.2 to −28.3° (Ph. Eur.: −27.6 to −29.0°). Arsenic, lead and mercury below the limit of quantification, cadmium 0.003 mg/kg in one batch; deoxynivalenol 149.2–386.8 μg/kg, aflatoxins 1.9–2.6 μg/kg, fumonisins 28.3 μg/kg in one batch. Dioxins and dl-PCBs upper bound 0.237 ng WHO-PCDD/F-PCB-TEQ/kg.
- Stability: losses below 3 % after 6 months of storage of the additive, no losses in a piglet premixture; pelleting at 73–75 °C and 3 months in feed without losses, negligible losses in water after 48 h at 20 °C. The coefficient of variation of total threonine in 10 subsamples of pelleted feed was 3 %, and after subtracting the feed’s protein-bound threonine (0.64 %) — 13 %. No viable cells or DNA of the production strain were detected.
- User safety: endotoxins in three batches below 300 IU/g (gel-clot test, Ph. Eur. 2.6.14), dusting potential below 100 mg/m³ (Stauber-Heubach method) — in a worst-case scenario EFSA calculated 17 IU of endotoxins per working day against a threshold of 900 IU. Lack of data prevented conclusions on skin and eye irritation or sensitisation. The act: rumen-protected threonine for ruminants, a label warning on the supply of essential amino acids, skin, eye and respiratory protection where procedures cannot eliminate the risks.