Identification of Producing Fibrinolytic Enzyme Strain from Starter and Its Enzymatic Properties

A strain producing fibrinolytic enzyme was isolated from starter.The strain was identified as Rhizopus micro-sporus var.tuberosus based on the morphological and ITS sequence.The enzymatic properties of the fibrinolytic enzyme secreted by the strain were determined.The properties tests suggest that the optimum temperature and pH were 37,℃ and 7.0r,espectively.The enzyme retained 95% of its initial activity by retaining for 4 h at 37,℃,and when it was treated at 57 ℃ for 4 h,the enzyme was still remained of activity.The enzyme had a wide range of pH adaptabilityi,t still remained of part of activity when pH was adjusted to a level(pH3.4);and it remained enzyme activity in between the range of pH 6.0-8.0.Zn2+ and Cu2+ have a very clear function to restrain the enzyme activity whereas Na+,Ca2+,Mn2+ showed obvious stimu-lation on the enzyme.The results show that the enzyme is stable in the artificial intestinal juicei,t retained 80% of its initial activity by retaining for 4 h at 37,℃.It may be developed to injection used in clinical research.