Abstract

The various nutrients belonging to carbon, nitrogen and amino acid sources, were investigated in terms of their effect on the production of extracellular protease byBacillus licheniformis ATCC 12759. Comparison with the control in media containing all the 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 and sodium nitrate were the best organic and inorganic nitrogen sources, respectively. Among the amino acid sources tested, L-phenylalanine, L-cysteine, glycine and L-valine favored the production, respectively. FeSO₄, ZnSO₄ and CuSO₄ completely repressed protease production. Maximum protease production (10738.2±44.2 U/mg) was obtained in a medium containing 0.1% MgSO₄ in 24 h 37°C.

Keywords: Bacillus licheniformis ATCC 12759, protease, submerged fermentation, enzyme production

Abbreviation

SmF, Submerged fermentation; SD, standard deviation.