Screening Of Alkaline Cellulose-Degrading Actinomyces Strain And Studies On Enzyme-Producing Conditions And Characters Of Enzyme Activity

Alkaline cellulase is broad used in hydrolyzing, washing, paper making, soil improving and so on when it exist in alkaline condition. Especially in paper making, the superiority of saving energy, water and reducing pollution as a high science and technology is expected by our society. Therefore, it is necessary to breed a strain and to find out its optimum fermentation condition.In this study, twenty strains were obtained by a rapid choosing method from sullage of paper mill, which could use CMC-Na as the exclusive carbon source. Four strains were gained by using exterior observation and Congo red dyeing. Using liquid culture and mensurated enzyme activities, finally obtained one strain and named Mys-5. From the study of its modality and physiological-biochemical characteristics ,we can preliminary identify the Mys-5 as a species of lntrasporangium sp.Optimized zymolytic conditions of Mys-5 by single-factorial experiments. The optimal compositions of fermentation medium were ultimately confirmed as follows, CMC-Na 20 g, (NH₄)₂SO₄ 2.0 g, CaCl₂ 0.3 g, MgSO₄·7H₂O 0.3 g, K₂HPO₄ 2.0g, FeSO₄, 0.005g. MnSO₄ 0.002g, ZnCl₂ 0.002g, CoGl₂ 0.002g adding water 900mL and reprovisioning 10% Na₂CO₃, mixed them as the proportion of 9:1 after sterilization. The optimal zymolytic conditions were the incubation temperature is 28℃, pH9.5-10, inoculum amount was 10%. Mn²⁺, Zn²⁺. Co²⁺ could promote enzyme activity, Contrarily Cu²⁺, Ag⁺ could restrain enzyme activity obviously.Enzymatic characteristics were also studied, the optimal conditions for reaction of alkaline cellulase produced by Mys-5 was pH 9.0 and the temperature was 40℃. When the temperature above 70℃, alkaline cellulase would lose its activity. The study showed that alkaline cellulase produced by Mys-5 could keep high activity in a broad rang of pH. which was suitable for the scour.