So the constitution of submerged fermentation medium optimizated may
improve enzyme activity of keratinase produced by B. licheniformis TCCC 11593.
Feather keratin contains a large number disulfide bond which is hydrolyzed dif-
ficultly by general enzymes. In the study of Shohei Yamamura, the disulfide
reductase has been research as disulfide bond-reducing enzyme [14]. As a consequence,
alkaline protease and neutral protease were blended with fermented
supernatant fluid in feather degrading process in order to investigate the potential
role of disulfide reductase deeply and improve the efficiency of the feather
degradation.