ABSTRACT
One alkaline protease from Actinomucor elegans AS3.2778 was purified protein. The enzyme was purified using ammonium sulfate precipitation, ion exchange chromatography, hydrophobic chromatography and size exclusion chromatography method, and its properties were also investigated. The molecular weight of this enzyme is 32 kDa with SDS-PAGE method, optimum temperature is 60℃, optimum pH is 8.5 to 10.5, it is stable in the pH range of 6.0 to 9.0 at < 40℃ temperature, and being completely inhibited by the serine protease inhibitor, PMSF, indicated that it belongs to the serine protease family. Specificity test indicated this protease has extensive selectivity to peptide bones, especially to peptide bones composed of Leucine residue.
ABSTRACT
One alkaline protease from Actinomucor elegans AS3.2778 was purified protein. The enzyme was purified using ammonium sulfate precipitation, ion exchange chromatography, hydrophobic chromatography and size exclusion chromatography method, and its properties were also investigated. The molecular weight of this enzyme is 32 kDa with SDS-PAGE method, optimum temperature is 60℃, optimum pH is 8.5 to 10.5, it is stable in the pH range of 6.0 to 9.0 at < 40℃ temperature, and being completely inhibited by the serine protease inhibitor, PMSF, indicated that it belongs to the serine protease family. Specificity test indicated this protease has extensive selectivity to peptide bones, especially to peptide bones composed of Leucine residue.
ABSTRACT
One factor at a time design and first order exponential model were applied to investigate the effects of the four major factors(temperature,ionic strength,pH and osmo-regulator) in the preservation process of nitrite oxidization bacteria(NOB),and a first order decay kinetics was introduced.The result showed that the anoxic decay rate of nitrifying bacteria reduced from 0.25 to 0.015,the half life was extend to 53d at 4℃,pH7.60,ionic strength 0.035mol/kg.The protecting effect of glycerin showed obviously better than that of other cryoprotectants at 4℃.