Sulfur-containing animal-feed additives

Abstract

The invention relates to sulfur-containing animal-feed additives produced from fermentation liquors, and to processes for their production.

1 - 11 . (canceled) 
     
     
         12 . A process for the production of a feed additive, comprising:
 a) separating a biomass completely from a fermentation liquor containing cysteine compounds selected from the group consisting of L-cysteine, L-cystine, thiazolidines, and salts thereof, and   b) optionally concentrating the mixture so obtained by removal of water.   
     
     
         13 . A process for the production of a feed additive that is low in biomass, comprising:
 a) separating virtually all or at least the predominant part of the biomass from a fermentation liquor containing cysteine compounds selected from the group consisting of L-cysteine, L-cystine, thiazolidines, and salts thereof, and   b) optionally concentrating the mixture so obtained by removal of water.   
     
     
         14 . A process for the production of a feed additive that is rich in biomass, comprising:
 a) leaving all or the majority of the biomass in a fermentation liquor containing cysteine compounds selected from the group consisting of L-cysteine, L-cystine thiazolidines, and salts thereof, and   b) optionally concentrating the mixture so obtained by removal of water.   
     
     
         15 . The process according to  claim 12 ,  13  or  14 , which further comprises:
 (c) preparing the feed additive product by drying, spray drying, spray granulating and granulating the fermentation liquor obtained.   
     
     
         16 . The process according to  claim 15 , wherein, for the preparation of the fermentation liquor containing cysteine compounds, L-cysteine-producing bacteria, fungi or yeasts are cultivated in said fermentation medium. 
     
     
         17 . The process according to  claim 16 , which further comprises one or more of the following steps:
 d) electrochemically reducing (electrolysis) L-cystine to L-cysteine in one or both of steps a) and b);   e) acidifying the fermentation medium with a concentrated mineral acid in one or both of steps a) and b);   f) adding a reducing agent to the fermentation medium of one or more of steps a), b) and c);   g) protecting the fermentation medium with a gas in one or more of steps a), b) and c);   h) adding an oxidizing agent to the fermentation medium of one or more of steps a), b) and c);   i) adding one or more cysteine compounds selected from the group consisting of L-cysteine, L-cystine and thiazolidines to the fermentation medium of one or more of steps a), b) and c), the added amount of cysteine compound being such that the total concentration thereof, optionally including its salts, in the animal-feed additive is in the range from 1 to 98 wt. %;   j) adding auxiliary substances to the fermentation medium of one or more of steps a), b) and c), for stabilization and increasing storability, selected from the group consisting of silicas, silicates, stearates, meals, brans, cereal flours, flours, silicas, silicates, starches and sugars; or   k) converting the substances obtained according to steps c) to j) into a form stable in an animal's stomach by coating the feed with a film-forming agent.   
     
     
         18 . The process according to  claim 17 , wherein the mineral acid is sulfuric acid. 
     
     
         19 . The process according to  claim 17 , wherein the reducing agent is one or more chemical compounds selected from the group consisting of vitamin C, vitamin E, formic acid and salts thereof. 
     
     
         20 . The process according to  claim 17 , wherein the oxidizing agent is at least one chemical compound selected from the group consisting of oxygen and hydrogen peroxide. 
     
     
         21 . The process according to  claim 17 , wherein the protecting gas is nitrogen. 
     
     
         22 . The process according to  claim 17 , wherein the film-forming agent is one or more substances selected from the group consisting of metal carbonates, silicas, silicates, alginates, stearates, starches, rubbers and cellulose ethers. 
     
     
         23 - 25 . (canceled)