Alkaline protease activity of a soil isolate of Beauveria felina for soy protein hydrolysis was explored and compared with Aspergillus oryzae NCIM 649, a known alkaline protease producer, under solid substrate fermentation (SSF) condition. The parameters affecting alkaline protease production under SSF condition were optimized. A maximum protease activity of similar to20,000 U/g initial dry substrate (IDS) was obtained from Beauveria felina grown for 7 days on wheat bran moistened with M-9 solution (pH 7.0) and 120% initial moisture content. As compared to Aspergillus oryzae NCIM 649, Beauveria felina showed about two times higher alkaline protease production under optimized conditions. The results demonstrated the potential of Beauveria felina isolate as a source of alkaline protease for commercial application to soy protein hydrolysis. (C) 2004 Elsevier Ltd. All rights reserved.