African Journal of

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12484

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.
Email: [email protected]

  •  Accepted: 06 May 2005
  •  Published: 31 July 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.