Production of alkaline proteases, related to various industrial applications, especially for "enzyme detergents", was done from a selected fungus Botrytis cinerea. Enzymes yield was maximized by optimizing the composition of a low-cost culture medium. The optimum fermentation conditions of proteases production were 28 degrees C, agitation at 150 rpm and an initial pH of media of 6.5. Mixtures of tryptone and yeast extract were good nitrogen sources while starch and especially molasses were suitable for enzymes production. The largest proteases activities was obtained in selected medium supplemented with algae (Spirulina algae), KCl, and oligo-elements. In fact. proteases production, not growth associated, seems to be modulated by an inducer system. The final proteases activities were 6.2-fold higher than that obtained in the initial conditions. The hyper-production of the extracellular proteolytic enzymes, their storage stability and thermostability, their compatibility with tested commercial detergents and performance in wash assay are features that prove their application in the laundry industry. (C) 2008 Elsevier Ltd. All rights reserved.