Full Length Research Paper

Production of β-mannanase by Bacillus amylolequifaciens 10A1 cultured on potato peels

Mona E. M. Mabrouk¹ and Amani M. D. El Ahwany²*

¹Botany Department, Faculty of Science, Damanhour Branch, Alexandria University, Egypt.

²Botany Department, Faculty of Science, Alexandria University, Egypt.

*Corresponding author. E-mail: amanielahwany@yahoo.com.

Accepted 7 March, 2008

Different Bacillus species were screened for the production of 1,4-β- mannanase on solid media. Bacillus amyloliquefaciens was selected as the most potent in producing enzyme of high activity. Utilization of various agro-industrial residues on mannanase production was evaluated. Potato peels at a concentration of 14 g/l was found to be the most effective carbon source. Maximum enzyme activity (61.5 U/mg protien) was obtained with ammonium nitrate as a nitrogen source. The optimum incubation temperature and pH for enzyme production were 35^oC and 7, respectively. The influence of inoculum size was so remarkable that, at optimum, a crude filtrate with an enzyme activity of 105.7 U/mg protien was obtained and appeared among the highest levels reported for mannanase titre. Addition of simple carbon source to media containing potato peels cause catabolic repression of mannanase synthesis.

Key words:  Bacillus amyloliquefaciens, β- mannanase, galactomannan, potato peels.