African Journal of Biotechnology Vol. 4 (7), pp. 633-638, July 2005          
ISSN 1684–5315 © 2005 Academic Journals

Full Length Research Paper

Studies on lysine production by Bacillus megaterium

I. A. EKWEALOR¹* and J. A. N. OBETA²

¹Department of Applied Microbiology and Brewing Nnamdi Azikiwe University, Awka Anambra State Nigeria.

²Department of Microbiology University of Nigeria Nsukka, Enugu State, Nigeria.

*Corresponding Author E-mail: amekwealor@yahoo.com; +234-8056420565.

Accepted 6 May, 2005

A Lysine-producing strain recovered from soil was found to produce large amount of the amino acid. The bacterium identified as Bacillus megaterium SP 14 accumulated a lysine yield of 3.56 mg/ml in a broth culture in 96 h.  Fermentation experiments show that 8.0% (w/v) glucose and 4.0% (w/v) ammonium chloride used as sources of carbon and nitrogen, respectively, in a medium/fermenter volume ratio of 25.0%, influenced accumulation of the amino acid. Amino acids other than the aspartate family at 0.01% (w/v) stimulated growth and improved lysine yield. Addition of 0.01 unit/ml penicillin to the fermentation medium, immediately after inoculation, stimulated growth and appreciably enhanced lysine accumulation.

Key words: Lysine, amino acid, Bacillus megaterium, fermentation, penicillin.