Search

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. [ABSTRACT FROM AUTHOR]

Abstract: Crab shell (CS) waste samples (particle size 3–10 and 20–35mm) were inoculated with the newly isolated Pseudomonas aeruginosa F722 to study the efficiency of microbial demineralization (DM) and deproteinization (DP) in the process of extracting chitin. The inoculated waste was incubated for 7 days at 25, 30 and 35°C. Various concentrations of glucose were supplemented as carbon source. At the optimal temperature of 30°C, DM was 92% and DP was 63% DP, whereas the pH dropped from initial pH 8.0 to 4.1. In comparative experiments with different amounts of CS waste, 5% CS waste treatment was shown to be the optimal amount for efficient DM. A positive relationship is correlated between DM and glucose concentration (r 2 =0.821), whereas a negative relationship is correlated between DM and pH (r 2 =0.793). DP and protease activity were little affected by different crab shell sizes. [Copyright &y& Elsevier]