African Journal of Biotechnology Vol. 5 (22), pp. 2312-2314, 16 November 2006   

ISSN 1684–5315 © 2006 Academic Journals        

Short communication

Screening of UV-irradiated and S-2-aminoethyl-L-cysteine resistant mutants of Bacillus megaterium for improved lysine accumulation

I. A. Ekwealor¹* and J. A. N. Obeta²

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

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

*Corresponding authors E-mail: amekwealor@yahoo.com.

Accepted 17 March, 2006

The screening of UV irradiated and aminoethyl-l-cysteine resistant (AEC^R) mutants of Bacillus megaterium strains for improved lysine accumulation was conducted. The mutants, MR-10 and MR-25 derived form irradiated cultures of B. megaterium SP 76, and MS-3 and MS-5 derived form B. megaterium SP 86 produced higher lysine levels than the parent strains. In contrast, however, lysine accumulation by MV-2 and MV-18 mutants of B. megaterium SP 14, was of low yield.  In aminoethyl-l-cysteine resistant mutants, R-14 and R-76, derived from B. megaterium SP 14 and B. megaterium SP 76 respectively, lysine accumulation was enhanced.

Key words: L-Lysine, fermentation, screening, mutants, accumulation.