High Level Production of Extracellular Protease from Bacillus licheniformis ATCC 12759 in Submerged Fermentation

Abstract

Production of extracellular protease by Bacillus licheniformis ATCC 12759 in submerged fermentation was the aim of this study. Various nutrients belonging to three categories, carbon, nitrogen and amino acid sources, were investigated in terms of their effect on the production of extracellular protease by Bacillus licheniformis ATCC 12759. Comparison with the control in media containing the all simple sugars resulted in a decrease in proteolytic activity, while there was significant increase in enzyme yield in the case of the supplementation complex carbon source such as wheat flour and rice flour. Urea, soy flour and sodium nitrate are the best organic and inorganic sources respectively. Among the amino acid sources tested, L-phenylalanine, L-cysteine, Glysine, L-valine, L-tyrosine, L-isoleusine, L-tryptophane and Glutamic acid favored the production respectively. FeSO4, ZnSO4 and CuSO4 inhibited protease production. Maximum protease production (10738.2 +/- 44.2 U/mg) was obtained in a medium containing 0.1% MgSO4 in 24 h 37 degrees C.