Evaluation of proteases produced by Erwinia chrysanthemi for the deproteinization of crustacean waste in a chitin production process

Abstract

  This study evaluated the potential use of proteases produced by Erwinia chrysanthemi for the extraction of pure chitin from crustacean wastes using standard methods. The crude bacterial protease had activity of 22.4 U/ml. Protein removal by the commercial protease were similar in both the mineralized and demineralized wastes and amounted to about 75 and 80%, respectively, in 16 h. A similar trend was observed with higher protein removal efficiency (95%) for the crude protease from both the mineralized and demineralized wastes. Also, treatment of the powder with 5% NaOH resulted in the removal of protein in the demineralized and mineralized wastes decreased by about 96 and 87.6%, respectively, in same period from an initial concentration of 0.3 mg/ml. It was concluded that proteases produced by E. chrysanthemi could be used to transform waste from sea-food processing industries into products of commercial value.   Key words: Erwinia chrysanthemi, extra cellular, proteases, chitin, value-added products.