| Use cellulase enzyme to degradation cellulose into energy is a hot research projects, however, the high cost of industrial enzyme preparation obstruct the ambitious goal. Through the screening high yield cellulose enzyme fungi and study the enzyme production characteristics is helpful to solve the problem. Hunan Agricultural Bioengineering Research Institute found a high yield cellulose enzyme fungi named Z90(Phoma putaminum) during the research. This research around the Z90screening, identification, ultraviolet mutagenesis, properties and fermentation enzyme production conditions on optimization.We through Congo red method screening and by DNS method screening, got a high yield cellulose enzyme fungi:Z90. The characteristic colonies observation, the bacteria and ITS the morphological observation sequence identification, preliminary confirmed fungi Z90for Phoma putaminum.Z90was researched by ultraviolet mutagenesis:after90s ultraviolet irradiation, we got a better fungi Z90-19with a higher enzyme production ability (CMCase:(7.73±0.13) U/mLFPA:(1.41±0.16) U/mL)We have also analyzed the main properties of cellulase and some factors interfering with catalytic reaction of enzyme, such as:pH、temperature、metal ions.The optimum medium for Phoma putaminum LYYZ90-19was studied by single factor experiment and response surface design with Minitab software.The results showed that the optimal medium is as follows (g/L):the bran, peptone and K2HPO4were4.27,0.79and0.59, respectively. Under the optimal culture the enzyme activity was13.47U/mL the optimization of ferment conditions for Phoma putaminum LYYZ90-19was studied by single factor experiment and response surface design with Design Expert software. The results showed that the optimal condition is as follows: the temperature, pH and inoculum size were27.4℃,6.88and6.75%, respectively. Under the optimal condition the enzyme activity was (18.21±0.3) U/mL. |
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