| In this paper, we get three species which produced high activity of cellulase frompaddy soil, rotten wood and ox dung. By modality and microscope observed andphysiological characteristic mensurated, we can identify:①the strain NC-1, NC-2,NC-4 and NC-6 belong to Fungi Imperfecti, Moniliales, Moniliaceace,Penicillium. frequentans.②the strain NC-3, NC-5 and NC-9 belong to FungiImperfecti, Moniliales, Moniliaceace, Cladosporium. cladosporioides③the strain NC-7and NC-8 belong to Aetinomyces, Strptomyces, Streptomyces. ambofaciens.Mutagenesis was applied to the strain of Cladosporium. cladosporioides NC-5by treating conidia with UV, DES, UV-DES. Then, we found we can get the bestresult in UV 70s-DES 75min, the lethality rate is 88.93％, the obverse variability is15.16％, we got the mutant L-5 strain, The CMC-Na activity of it was increased14.92％. The filter paper activity of it was increased 28.57％. Mutagenesis wasapplied to the strain of Penicillium. frequentans NC-2 by treating conidia with UV,DES, UV-DES. Then, we can get the best result in UV 90s, the lethality rate is97.89％, the obverse variability is 7.35％, we got the mutant L-2 strain, The CMC-Naactivity of it was increased 10.47％. The filter paper activity of it wasincreasedl 9.54％. Mutagenesis was applied to the strain of Streptomyces. ambofaciensNC-7 by treating conidia with UV, DES, UV-DES. We found we can get the best resultin DES 60min- UV 70s, DES 60min- UV 80s. This process resulted in the isolation oftwo new mutants which produced higher activity of cellulose, which are X402 andP303. The CMC-Na activity of them were 48.33IU/ml and 53.90IU/ml, which wereincreased 13.21％and 23.92％. The filter paper activity of the two new mutants were28.54IU/ml and 25.15IU/ml, which were increased 38.95％and 22.44％.After optimizing Streptomyces. ambofaciens P303 by submerged fermentation,we get the best condition of medium: the percentage of rice straw powder to wheatbran is 3:1 as carbon source and the percentage of carbamide to NH4Cl is 3:1 asnitrogen source, the inoculation amount is 10.0％, the volume of medium of 60ml inmeasuring flask of 250ml, the optima pH is 5.0～6.0, the optima temperature is 37℃,the stable temperature is 35～39℃, under the above conditions and growing120h, we got the highest activity of CMC and FPA, but under the above conditionsand growing 144h, we got the highest activity ofβ-glucosidaseo After fermenting, we get CMC activity,β-glucosidase activity and FPA activity of Streptomyces.ambofaciens P303 is 7.76 IU/ml, 3.57IU/ml and 4.03IU/ml, Which increased 81.73％,363.64％and 96.59％than the activity of preliminary screening NC-7. That showscellulases have highβ-glucosidase activity and FPA activity.The optima reactive condition of cellulase of Streptomyces. ambofaciens P303 is:The optima temperature in enzymolysis of CMC activity,β-glucosidase activity andFPA activity is 60℃,60℃,65℃relatively; the optima pH in enzymolysis of CMCactivity,β-glucosidase activity and FPA activity is 7.0, 7.0 and 8.0, the optima time inenzymolysis of cellulase activity is 30min. Ca2+,Zn2+,Co2+ will activate cellulaseactivity, Mg2+,Cu2+ will inhibit feebly cellulase activity. Mn2+ will inhibit feebly CMCactivity andβ-glucosidase activity, but will activate FPA activity, Fe3+have littleinfluence in cellulase activity. CMC activity will be stable below 70℃,β-glucosidaseactivity will be stable below 65℃, FPA activity will be stable below 70℃. CMCactivity will be stable between pH 6.0 and pH9.0,β-glucosidase activity will be stablebetween pH 6.0 and pH10.0, FPA activity will be stable between pH7.0 and pH11.0.That shows cellulase of Streptomyces. ambofaciens is megatemperature alkali enzyme,it can maintain high activity in high temperature and alkaline condition.
|
PDF Full Text Request