丝素肽酶法生产工艺条件研究

筛选出 2种水解效率较高的Alcalase酶和Flavourzyme 5 0 0MG酶水解丝蛋白 ,确定其最适酶解工艺条件为 :脱脂蚕茧用 10 0℃ ,0 5 %Na2 CO3溶液脱胶 3 0min(固液比 1∶15 )得丝素 ,经用 5 5℃、40 %CaCl2 水溶液溶解 (固液比 1∶10 )及MWCO5 0 0超滤膜 5 5℃超滤去离子后 ,用Alcalase酶于 pH7 5、5 5℃水解 12 0min(加酶量 0 3 5g/L) ,然后用Flavourzyme 5 0 0MG酶于pH6 5、5 0℃水解 2 40min(加酶量 0 2 0g/L)。在此工艺条件下 ,丝素蛋白经酶解降解成各种分子质量的多肽、短肽或氨基酸 ,其中分子质量 10 0 0 0u以内的多肽、短肽、氨基酸含量达到总量的 92 4% ,游离氨基酸含量为 14 6g/L ,占总量的 2 1%。

Study on Technical Conditions of Silkworm Cocoon Fibroin Hydrolysed with Enzymes

Alcalase and Flavourzyme 500MG were selected to hydrolysed fibroin because of their high efficiency,the optimum technical conditions are: firstly,defated cocoon was degumed in 100℃0 5% Na 2CO 3 solution for 30?min(silk solid∶solution was 1∶15),then degumed silk was dissolved in 55℃40% CaCl 2(silk solid∶solution was 1∶10) and deoinized with MWCO 500 UF membrane at 55℃; secondly,fibroin was hydrolysed with Alcalase at the reaction condition of pH7 5,55℃,0 35?g/L amount of enzyme for 120min,followed by Flavourzyme hydrolyzation at pH6 5,50℃,0 20?g/L amount of enzyme for 240min Hydrolysate produced with the optimum conditions covered different small molecular peptides and amino acids, and the amount of peptides and amino acids whose molecular weight were below 10000 was about 92%,the free amino acids content was 14 6?g/L,up to 21% of the total amount