摘要
Abstract
Shrimp head shell, the by -product of shrimp processing, was used to prepare chitin. The yield of chitin was 16. 11 ±0.73% by acid pickling and alkali cooking method. The yield of chitosan (compared to chitin) was 68.07 ± 1.60% by concentrated alkali treatment. Then, cellulase was used to degrade chitosan into oligochitosan. The effects of enzyme amount, pH, temperature, reactive time on degradation of chitosan and substrate concentration were studied. The results showed thatthe optimum cellulase depolymerization conditions were; chitosan concentration 0.5%, the mass of cellulose 8IU/ (g/substrate) , pH 5. 0, temperature 60t , reaction time 4h. Using ethanol precipitation, the results were; in 75% ethanol precipitation, chitosan yield was 2. 36 ±0. 15% , the average degree of polymerization was 9; in 87. 5% ethanol precipitation, the yield wasO. 85 ±0. 15% , and the average degree of polymerization was 7 ; in 87. 5% ethanol supernatant, the yield was 79. 84 ±0. 10% , the average degree of polymerization was 5. The yield of oligochitosan with polymerization less than lOafter cellulase degradation was 8. 8%.关键词
虾头壳/纤维素酶/降解/聚合度/低聚壳聚糖Key words
shrimp head shell/ cellulase/ degradation/ average degree of polymerization/ low chitosan分类
轻工纺织
