Friday, 2 December 2011

L-Lysine Production


L-Lysine Fermentation
Out of 20 naturally occurring amino acids, L- lysine is one of 9 essential amino acids and commercially important amino acids. It is mainly used as feed additive in the animal feed industry; mixed with various common livestock such as cereals which do not contain sufficient levels of L-Lysine for the livestock’ nutritional requirements, in especially monogastric animals like broilers, poultry and swine and as a supplement for humans and improving the feed quality by increasing absorption of other amino acids.
L-Lysine can be produced by chemical or biochemical method; whichever is more economic. Gram+ve cyanobacteria strains like Corynebacterium glutamicum, Brevibacterium flavum are used for industrial production.

Fermentation Medium:
Apart from physical parameters like pH, Agitation and aeration rate and temperature; media composition is very important factor.
The seed culture to be prepared includes:
Glucose: 20g                                                     
Peptone: 10g                                                 
Meat extract: 5g                                               
Sodium chloride: 2.5g in 1 litre of tap water     
Seed culture obtained is reinoculated for 2nd seed culture in media containing:
Molasses: 200g                                                   
Soy protein hydrolysate 18g in 1L tap H2O        
Above culture is reinoculated with B.flavum     
Acetate is used as C source                                 
After obtaining first and second media production media is used which includes:
Cornsteep liquor
Ammonium sulphate
Glycerol                             
CaCO3
Incubation for 72 hours at 28 degrees
Recovery:
Fraction of lysine fermentation broth is obtained by any suitable, Methods such as Ultrafiltration or Centrifugation. In order to overcome difficulties of high viscosity in culture broth; filterability can be improved by adding a mineral acid like conc. H2SO4 and then heat the culture broth at 100degrees for at least 5 minutes. The resulting product is L lysine.


No comments:

Post a comment