L-lysine-containing feed additives

Abstract

The invention relates to relatively light and thermally stable granulated, fermentation-broth-based animal feed additives having a high content of L-lysine and to low-loss methods for their production from broths obtained by fermentation.

1 . Granulated fermentation-broth-based feed additive having 
 a) an L-lysine content of 10 to 70% by weight (calculated as base, based on the total weight), in particular 30 to 60% by weight,    b) a water content of 0.1 to 5% by weight (based on total weight), and    c) a sulphate/L-lysine ratio of 0.85 to 1.2, this ratio being calculated according to the formula 2×[SO 4   2− ]/[L-lysine]=ratio.    
     
     
         2 . Feed additive according to  claim 1  having a pH of 3.5 to 5.1, measured in a 10% strength by weight aqueous suspension.  
     
     
         3 . Feed additive according to  claim 1 , up to >97% of which has a mean particle size of 0.1 to 1.8 mm.  
     
     
         4 . Feed additive according to  claim 1 , the surface of which is coated with an oil in an amount of 0.02 to 2% by weight, based on the total amount of the feed additive.  
     
     
         5 . Feed additive according to  claim 1 , the colour values of which are in the following ranges: (measurement of diffuse reflection of the sample at an angle of 8°) 
 L*65-80 (black-white range)    a*4-8 (red-green range)    b*20-30 (yellow-blue range).    
     
     
         6 . Method for producing a granulated L-lysine-containing feed additive by fermentation of an L-lysine-producing microorganism in an aqueous medium under aerobic conditions, wherein, after completion of the fermentation 
 a) the sulphate/L-lysine ratio in the fermentation broth is optionally determined,    b) subsequently ammonium sulphate is optionally added and    c) the pH is lowered by adding sulphuric acid to 4.9 to 5.2, a sulphate/L-lysine ratio of 0.85 to 1.2 being set in the broth by addition of the sulphate containing compounds, and    d) the resultant mixture is optionally concentrated, granulated and a product is obtained which has an L-lysine content of 10 to 70% by weight (determined as lysine base, based on the total amount).    
     
     
         7 . Method according to  claim 6 , in which the broth is concentrated by removal of water between steps c) and d).  
     
     
         8 . Method according to  claim 6 , in which the sequence of the additions of ammonium sulphate and sulphuric acid is turned the other way round.  
     
     
         9 . Method according to  claim 6 , in which, before the concentration, ammonium-, earthalkali- or an alkali metal hydrogensulphite or mixtures thereof are added in an amount of 0.01 to 0.5% by weight, based on fermentation broth.  
     
     
         10 . Method according to  claim 6 , in which, after completion of the fermentation, 0 to 100% of the biomass formed during the fermentation is removed and steps a) to d) follow.  
     
     
         11 . Method according to  claim 6 , in which the surface of the granules is coated with an oil in an amount of 0.02 to 2% by weight, based on the total amount of the feed additive.  
     
     
         12 . Method according to  claim 6 , in which coryneform microorganisms are used.  
     
     
         13 . Method according to  claim 6 , in which corynebacteria are used.