Study Of Extracting Chitin From Shrimp Shell With Biological Method

Chitin and its derivatives have good bioactivities such as biocompatibility, biodegradability and non-toxic, these bioactivities make it widely applied in sewage treatment, food industry, agriculture, paper industry, cosmetics and biomedical. The traditional method of extracting chitin is treating shrimp shell with large amounts of acid and alkali,this method is of high cost and environment pollution. This project uses shrimp shell as raw material and optimized the removal method of mineral and protein in shrimp shel, the main results are as follow.(1) In this study, Bacillus coagulans was screened out because of its good character of acid production. Through the single factor experiment and orthogonal experiment, fermentation condition and medium were optimized. the optimum results are as follow: initial p H of medium 8.6, fermentation temperature 45℃,10% inoculum size, shaker speed 100r/min, 5% shrimp shell, 10% glucose, the demineralization can reach about 91% after 3 days of fermentation.(2) Proteinase K was selected for removal of protein from shrimp shell, the optimum conditions of deproteinization are as follows: 10% shrimp shell, 1000U/g enzyme supplementation, hydrolysis temperature 60℃, pH 8.0, hydrolysis time 12 h. Under the optimized condition of enzymatic hydrolysis, proteinase K can reach abo ut 82.62% of proteinization.(3) In the study of synergistic fermentation of Bacillus coagulans and proteinase K, 10% inoculums size of Bacillus coagulans and 1000U/g enzyme supplementation of proteinase K were added into the medium without sterilization at the same time, the medium was consist of 5% shrimp shell and 10% glucose. Under the conditions of 50℃, 100r/min shaker speed, 3days of fermentation time, approximately 93% of deproteinization and 91% of demineralization can be reached. Through infrared spectrum analysis, the fermentation product was proved to be chitin.