L-lysine sulphate (3c324i), L-lysine sulphate - 3c323i

In the current applications authorisations are sought under Article 4(1) for L-lysine sulphate produced by fermentation with Corynebacterium glutamicum KCCM 80227 and L-lysine sulphate produced by fermentation with Escherichia coli CGMCC 7.398, under the category/functional group 3(c) 'nutritional additives'/'amino acids, their salts and analogues', according to Annex I of Regulation (EC) No 1831/2003. The authorisations are sought for all animal species. 

According to the Applicants, the feed additives contain a minimum of 52 % (w/w) of L-lysine in L-lysine sulphate produced by fermentation with Corynebacterium glutamicum KCCM 80227 and a minimum of 55 % (w/w) of L-lysine in L-lysine sulphate produced by fermentation with Escherichia coli CGMCC 7.398.

The feed additives are intended to be added directly into feedingstuffs or through premixtures. However, the Applicants did not propose any minimum or maximum content of L-lysine sulphate in feedingstuffs. 

For the identification of the sulphate in L-lysine sulphate the EURL found the European Pharmacopoeia monograph (Ph. Eur. 01/2008:20301). 

For the quantification of lysine in the feed additive and premixtures the Applicants proposed the ring-trial validated method EN ISO 17180:2013 based on ion-exchange chromatography (IEC) coupled with optical (visible – VIS or fluorescence – FLD) detection which is dedicated for the determination of lysine, methionine and threonine in commercial amino acid products and premixtures containing more than 10 % of amino acid. The method does not distinguish between the amino acids and their salts, or between different salts of the same amino acids, and it cannot differentiate between enantiomers. The following performance characteristics were reported in the frame of the ring-trial validation studies for the quantification of free lysine: a relative standard deviation for repeatability (RSD_r) ranging from 0.7 to 1.7 %; and a relative standard deviation for reproducibility (RSD_R) ranging from 1.5 to 2.5 %. 

For the quantification of lysine in feedingstuffs the Applicants proposed the European Union (EU) method dedicated for the determination of amino acids in feed. This method is designed for the quantification of free (synthetic and natural) and of total (peptide-bound and free) amino acids in premixtures and feedingstuffs, using an amino acid analyser or ion-exchange chromatography (IEC) coupled with post-column derivatisation and optical (VIS) detection. The method does not distinguish between the amino acids and their salts, or between different salts of the same amino acids, and it cannot differentiate between enantiomers. The following performance characteristics were reported in the frame of the ring-trial validation studies for 

the quantification of total lysine: RSD_r ranging from 2.1 to 2.8 % and RSD_R ranging from 3.0 to 6.7 %. 

Based on the performance characteristics available, the EURL recommends for official control (i) the European Pharmacopoeia monograph (Ph. Eur. 01/2008:20301) for the identification of the sulphate in L-lysine sulphate; (ii) the ring-trial validated method EN ISO 17180:2013 based on ion-exchange chromatography coupled with optical (visible or fluorescence) detection (IEC-VIS/FLD) to quantify free lysine in the feed additive and premixtures (containing more than 10 % lysine); and (iii) the ring-trial validated European Union (EU) method based on IEC-VIS for the quantification of lysine in premixtures and feedingstuffs. 

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.

Recommended Method

as of:

- Commission Implementing Regulation (EU) 2021/2095

- Commission Implementing Regulation (EU) 2022/1469

For the identification of sulphate in the feed additive:

— European Pharmacopoeia Monograph 20301

For the quantification of lysine in the feed additive and premixtures containing more than 10 % lysine:

— ion exchange chromatography coupled with post-column derivatisation and optical detection (IEC-VIS/FLD) – EN ISO 17180

For the quantification of lysine in premixtures, compound feed and feed materials: 

— ion exchange chromatography coupled with post-column derivatisation and optical detection (IEC-VIS), Commission Regulation (EC) No 152/2009 (Annex III, F)

as of:

- Commission Implementing Regulation (EU) 2021/2095

For the quantification of lysine in water:

— ion exchange chromatography coupled with post-column derivatisation and optical detection (IEC-VIS/FLD)