Bioconversion of shrimp waste Penaeus merguiensis using lactic acid fermentation: An alternative procedure for chemical extraction of chitin and chitosan

Chitin extraction from shrimp wastes by biological treatment, using the Pseudomonas aeruginosa was a positive and simple method. In order to look for the optimal conditions, the wastes were incubated at 30 °C and 100 rpm in different glucose (0%, 10%, 15% and 20%) and inoculation (10%, 15% and 20%) concentrations for 4 and 6 days. At the end of fermentation, Protease activity was investigated at different temperatures and temperature 50 °C was considered as the optimum. The results obtained also showed a direct relationship between the concentration of different parameters and deproteinization and demineralization rates, so that the optimal conditions were 20% glucose, 20% inoculation and 6 days fermentation. These conditions led to 82% demineralization, 92% deproteinization and chitin yield of 47%. Then, chitin was converted to chitosan using microwave, autoclave and traditional methods. The highest yield (87%) was obtained with autoclave method. At the end, the chitin and chitosan were characterized by elemental analysis and FTIR.