L-isoleucine from non-modified Corynebacterium glutamicum CGMCC 20437 (3c385): at least 93.5 % DM, optical rotation of one batch below the Ph. Eur. range, dusting potential up to 2.5 g/m³, distribution in feed after subtracting the background — CV 23 %
Commission Implementing Regulation (EU) 2025/143, published on 30 January 2025, authorises until 19 February 2035 L-isoleucine produced with Corynebacterium glutamicum CGMCC 20437 as a nutritional additive for all animal species, in feed and in water for drinking. According to the EFSA opinion of 12 March 2024 (applicant: Eppen Europe SAS) the strain is not genetically modified, and no viable cells of it were detected in the product.
- Specification: powder with at least 93.5 % L-isoleucine on a dry matter basis and at most 2 % moisture (C6H13NO2, CAS 73-32-5). Methods: identification according to the Food Chemical Codex L-isoleucine monograph; in the additive ion-exchange chromatography coupled to post-column derivatisation and optical detection (IEC-VIS/FLD or IEC-VIS); in premixtures IEC-VIS/FLD or IEC-VIS according to Regulation (EC) No 152/2009; in compound feed IEC-VIS (152/2009); in water IEC-VIS. For this additive the act does not cite EN ISO 17180.
- EFSA data: five batches averaged 98.4 % isoleucine in DM (98.0–98.8 %), loss on drying 0.2–0.3 %. The specific optical rotation of three batches, +39.5 to +40.1°, was within the applicant’s specification (+38.5 to +41.5°), but one batch deviates from the European Pharmacopoeia range (+40 to +43°). Cadmium 0.0021 mg/kg, lead 0.01–0.012 mg/kg (below the LOQ in one batch), mercury 0.016–0.017 mg/kg; mycotoxins below the limits of detection or quantification.
- Dioxins and dl-PCBs below the LOQ except PCB 105 in one batch (8 ng/kg); upper bound 0.137 ng WHO-TEQ/kg for PCDD/Fs and 0.269 ng WHO-TEQ/kg together with dl-PCBs, sum of ndl-PCBs 0.003 mg/kg. No losses after 6 months in the additive and a premixture, after 3 months in mash and pelleted feed (pelleting at 81 °C) and after 48 h in water. In 10 subsamples of pelleted feed the CV of total isoleucine was 4.1 %, and after subtracting protein-bound isoleucine (0.85 %) — 23.0 %.
- Users: the dusting potential of three batches was 1.3–2.5 g/m³ (Stauber-Heubach), so EFSA considered exposure by inhalation likely; no data on skin and eye irritation or sensitisation were submitted. The act: rumen-protected isoleucine for ruminants, a label warning on the supply of essential amino acids when given in water (EFSA has concerns about simultaneous administration via water and feed), skin, eye and respiratory protection where procedures cannot eliminate the risks.