RESEARCH OF OPTIMIZATION OF NITROGEN COMPOSITIONS FOR L-LYSINE PRODUCING MEDIUM BY CORYNEBACTERIUM GLUTAMICUM CG2

Abstract

L-Lysine is an essential aminoacid added as supplement for aquatic feed and is produced mainly by microbial fermentation. Medium composition is a very important factor, influencing the fermentation of L-Lysine-producing bacteria. Nitrogen source is usually the most high-priced constituent of bacterial growth media. The nitrogen contents of medium for Corynebacterium glutamicum CG2 growth was optimized targeting enhanced L-Lysine production were tested and selected, including inorganic and organic nitrogen sources of single, mixture and the ratio of their compounds. Maximum concentration of lysine was 45.7g/L with the optimized nitrogen formulated media (urea -7.4g/l and fish hydrolysates -10g/l) when cultured in a 10L bioreactor.