Abstract
Cellulases have a potential for use in biotechnology and industry such as in starch processing, alcoholic beverage manufacture, malting and brewing, clarification of juice, pulp bleaching, textile manufacturing and animal feed production. Thirty one thermophilic and cellulolytic bacteria were successfully isolated from a southern region of Saudi Arabia. The phylogenetic analysis of the promising isolate using its 16S rDNA sequence data showed its highest homology (99%) with Geobacillus stearothermophilus. The analysis was performed to evaluate cellulase production using untreated and both alkaline and acid-steam treated date palm wastes as carbon sources. The optimal conditions for cellulase production consisted of a 2.5% alkaline-treated date palm leaf base with pH at 7.0- 7.5, a cultivation temperature at 45-50 degrees C, an agitation rate of 200 rpm, and 0.2% Tween 80 and yeast extract as a best nitrogen source when fermentation was extended up to 48h. The results indicated that the utilization of date palm waste as a cheap substrate for the production of cellulases had potential, and could reduce environment pollution.