Production of chitin and bioactive materials from Black tiger shrimp (Penaeus monodon) shell waste by the treatment of bacterial protease cocktail

The main objective of this study was to obtain chitin in pure form from a new crustacean waste material for industrial applications. Black tiger shrimp shell wastes are a rich source of protein and valuable bioactive carbohydrate polymers such as chitin. After removal of carotenoid, Black tiger shrimp shell wastes (BTSHWs) were treated with chemicals and protease enzyme to extract chitin. Box-Behnken response surface methodology was applied to optimize the deproteinization process to obtain chitin. At optimal pH (8.82), temperature (50.05 °C), agitation speed (100.98 rpm), enzyme substrate ratio of 1:8 (wv-1) and 72 h of incubation with Paenibacillus woosongensis TKB2 crude protease cocktail, 80 % deproteinization was found along with 77.28 % recovery of chitin. The valuable oligopeptides were determined by MALDI-TOF analysis and analysis of adequate amount of free amino acids in protein hydrolysate from BTSHW, indicating a high nutritional value used for food, feed or as a nitrogen source in growth medium for microorganisms. The chitin obtained was compared with the commercial chitin using scanning electron microscopy, Fourier transform infrared spectrometer, X-ray diffraction and 13C CP/MAS-NMR. Chitin obtained from crude protease treatment showed comparable physicochemical and structural properties to those of the commercial chitin. The carotenoid obtained after treatment can be used for medicinal purpose.