Abstract— Enzymatic stability is undoubtedly one of the most important factors in biotechnology. In this sense, the stability of cellulases present in crude extracts of submerged cultures of Bacillus sp. SMIA-2 in the presence of commercial detergents and proteases® was studied. Cellulases were resistant to digestion by proteases which is an interesting feature of these enzymes for application in detergent formulations.