African Journal of Biotechnology Vol. 6 (8), pp. 1048-1054, 16 April 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Optimization of cellulase and β-glucosidase induction by sugarbeet pathogen Sclerotium rolfsii

Tarek A. A. Moussa* and Nagwa A. Tharwat

Department of Botany, Faculty of Science, University of Cairo, Giza 12613, Egypt

*Corresponding author. E-mail: tarekmoussa@yahoo.com. Fax: (002) 02 57 000 88.

Accepted 15 January, 2007

The ability to produce cellulose degrading enzymes by sugarbeet pathogen Sclerotium rolfsii Sacc. in liquid synthetic media with carboxymethy cellulose (CMC) as inducer was studied. Several cultural conditions were examined to assess their effect in optimizing enzymes production. Shaking cultures gave higher yields of cellulases compared with static ones. Aspargine supplement was the best nitrogen source, especially at 3.0 g/l concentration, in promoting enzyme production. Variation of cellulose/xylan ratio in the culture medium showed that cellulose and xylan induced both cellulases synthesis but cellulose being the most effective specific substrate. The influence of different inhibitors on enzymes production by S. rolfsii was also studied. Cyclohexmide and ethidium bromide inhibited protein synthesis by S. rolfsii. Moreover, glucose repressed cellulase synthesis in S. rolfsii.

Key words: Cellulase, β-glucosidase, inhibitors, Sclerotium rolfsii.