The effects of some sugars(glucose,mannose,fructose,sucrose and chitosan)and polyols(glycol,gly-cerol and sorbitol)as protective additive on the thermo-stability ofβ-mannanase were studied.The optimal reaction temper...The effects of some sugars(glucose,mannose,fructose,sucrose and chitosan)and polyols(glycol,gly-cerol and sorbitol)as protective additive on the thermo-stability ofβ-mannanase were studied.The optimal reaction temperatures ofβ-mannanase and the ther-modynamics and the deactivation kinetics with or without additives were also investigated.The experimental results show that sucrose,chitosan and sorbitol could apparently improve the thermal stability ofβ-mannanase when their concentration was kept at 2 g/L.The optimal combina-tion additive proportion was sucrose:chitosan:sorbi-tol=1:2:2(molar ratio)using the orthogonal experimental design.The sucrose,chitosan,glycerol,sor-bitol and the combination additive might increase the optimal reaction temperature from 50℃to about 60℃due to their good protection effect.The thermal deactiva-tion curves ofβmannanase accorded with the kinetic rules of first order reaction,and the corresponding kinetic and thermodynamic parameters were calculated.Meanwhile,the protective mechanism of the additives against deactivation of enzyme was also discussed.展开更多
基金supported by the Tianjin Science&Technology Commission of China(No.05YFGZGX04600)the National Key Technology R&D Program(No.2007BAD42B02)the International Science and Technology Cooperation Program(No.2006DA62400).
文摘The effects of some sugars(glucose,mannose,fructose,sucrose and chitosan)and polyols(glycol,gly-cerol and sorbitol)as protective additive on the thermo-stability ofβ-mannanase were studied.The optimal reaction temperatures ofβ-mannanase and the ther-modynamics and the deactivation kinetics with or without additives were also investigated.The experimental results show that sucrose,chitosan and sorbitol could apparently improve the thermal stability ofβ-mannanase when their concentration was kept at 2 g/L.The optimal combina-tion additive proportion was sucrose:chitosan:sorbi-tol=1:2:2(molar ratio)using the orthogonal experimental design.The sucrose,chitosan,glycerol,sor-bitol and the combination additive might increase the optimal reaction temperature from 50℃to about 60℃due to their good protection effect.The thermal deactiva-tion curves ofβmannanase accorded with the kinetic rules of first order reaction,and the corresponding kinetic and thermodynamic parameters were calculated.Meanwhile,the protective mechanism of the additives against deactivation of enzyme was also discussed.
