Any of a group of protein-digesting enzymes (see protease) produced by Bacillus subtilis and related species. Subtilisins have broad specificities and work over a wide range of pH values. Subtilisin Carlsberg is an alkaline protease, derived from Bacillus licheniformis, that is used widely in detergents. Roughly 30–40% of the peptide bonds in casein, a milk protein, are hydrolysed by subtilisin Carlsberg. Homologous proteins are also found in plants, such as melon and tomato.