Research Article

Keratinase Production by Three Bacillus spp. Using Feather Meal and Whole Feather as Substrate in a Submerged Fermentation

Figure 4

Gelatin (a) and keratin (b) zymogram analysis of extracellular peptidases from B. subtilis 1270, B. subtilis 1273, B. licheniformis 1274 grown in feather (F) or feather meal medium (FM). Gel strips containing concentrated culture supernatant were incubated for 48 h at 37°C in citric acid buffer pH 5.0. The approximate molecular mass of the peptidases is shown on the left.