Objective: The aim of the present study was to purify and determine the molecular weight of keratinase isolated from Streptomyces malaysiensis.Methods: For that purpose purification was done using ammonium sulphate and Sephadex-LH 100 column chromatography. Further, the fractions were pooled and subjected to molecular weight determination using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE).Results: The obtained results showed keratinase with 47.57% recovery, 3.5-fold purification and an estimated molecular mass of 27,000 Da. Keratinase showed an optimal activity at 60 οC and pH 8. Keratinase activity of the purified product was assayed with feather powder as a substrate. The isolated strain was identified as Streptomyces malaysiensis based on phylogenetic tree analysis. The strain isolated from termite mound soil showed the highest keratinase activity, which could be considered a microorganism of environmental origin.Conclusion: The production of keratinase on simple media with feathers as sole source allowing its production from the cheap substrate and a commercial production with low production cost. Stability in the presence of detergents, surfactants and solvents make this keratinase extremely useful for a biotechnological process involving keratin
