(5)In view of the above, the Commission considers that L-isoleucine produced with Escherichia coli CCTCC M 20231916 satisfies the conditions provided for in Article 5 of Regulation (EC) No 1831/2003. Accordingly, the use of that substance as a feed additive should be authorised. The Commission considers that possible hygiene risks related to the use of this amino acid in water for drinking, are to be addressed by feed business operators under their obligations to ensure compliance with the relevant hygiene requirements laid down in Regulation (EC) No 183/2005 of the European Parliament and of the Councilnote laying down requirements for feed hygiene. When fed to ruminants, L-isoleucine produced with Escherichia coli CCTCC M 20231916 should be protected against degradation in the rumen. It is appropriate to alert the user to take into account the dietary supply with all the essential and conditionally essential amino acids, in particular in the case of supplementation with L-isoleucine via water for drinking. In addition, the Commission considers that appropriate protective measures should be taken to prevent adverse effects on the health of the users of the additive.