Separation, Purification and Enzymatic Property of Cellulase Produced by Thermostable Bacillus amyloliquefaciens BA-DES4

Objects: This research was performed based on taking one Bacillus amyloliquefaciens BA-DES4 producing the cellulose as the material, and the enzymatic property of its cellulose was researched upon the purification. Methods: This research applied the ammonium sulfate fractional precipitation and SephadexG-75 gel filtration chromatography method to carry out the separation and purification to the cellulose it produced. Determined its molecular weight by means of polyacrylamide gel electrophoresis (SDS-PAGE), and carried out the research of enzymatic property to enzyme solution of cellulase upon purification. Results: The cellulase system components could be obtained in zymotic fluid upon separation and purification (endoglucanase), and its specific activity was 51.08 U/mg through carrying out the measurement of enzyme activity to purified electrophoresis endoglucanase. It was identified that its molecular weight was 22.4 kDa. The primary research of enzymatic property indicated that the optimal reaction temperature and optimal pH for this enzyme were 65 ℃ and 6.0 respectively with a high stability when pH was 5.0～7.0 and temperature was 55～65 ℃. The activation of Mn²⁺ to cellulase activities was significant with the highest inhibiting effect of Cu²⁺. Conclusion: This bacterial strain can be used as the potential strain for producing the endoglucanase with the enzymatic activities of endoglucanase can be promoted under the effects of Mn²⁺, Fe²⁺. Meanwhile, it can work under the high temperature and acid environment along with participating in the cellulose of high effective degradation and high-temperature acid environment so as to improve the production efficiency. The glucose to be decomposed can be used for fermentation with a potential of producing the fermented wine by applying the high-temperature Daqu, which has laid a foundation for further studying this cellulase.