摘要
[Objective] The aim was to screen strains producing alkaline protease from soil and study the conditions for enzyme production.[Method] Eight strains producing alkaline protease were isolated from soil through plate isolation,and the ability of enzyme production was measured by filter paper and Folin-phenol method.The strain with the strongest ability of enzyme production was screened as a candidate strain,then the factors influencing the ability of enzyme production was studied,finally the conditions for enzyme production was optimized through orthogonal test.[Result] No.5 strain was screened as a candidate strain due to its strong ability of enzyme production(6.00 U/ml),which accounted for 134.1% of that of Bacillus licheniformis,and it was gram-positive bacterium belonging to Clostridium.Orthogonal test showed that the optimal condition for producing protease was an environment with pH=11,0.3% of sucrose and 0.8% of peptone in the fermentation medium,and inoculation amount was 105 cfu/ml.In addition,peptone had significant impact on the level of enzyme production.[Conclusion] The study could provide theoretical references for the screening of strains producing alkaline protease.
[Objective] The aim was to screen strains producing alkaline protease from soil and study the conditions for enzyme production.[Method] Eight strains producing alkaline protease were isolated from soil through plate isolation,and the ability of enzyme production was measured by filter paper and Folin-phenol method.The strain with the strongest ability of enzyme production was screened as a candidate strain,then the factors influencing the ability of enzyme production was studied,finally the conditions for enzyme production was optimized through orthogonal test.[Result] No.5 strain was screened as a candidate strain due to its strong ability of enzyme production(6.00 U/ml),which accounted for 134.1% of that of Bacillus licheniformis,and it was gram-positive bacterium belonging to Clostridium.Orthogonal test showed that the optimal condition for producing protease was an environment with pH=11,0.3% of sucrose and 0.8% of peptone in the fermentation medium,and inoculation amount was 105 cfu/ml.In addition,peptone had significant impact on the level of enzyme production.[Conclusion] The study could provide theoretical references for the screening of strains producing alkaline protease.
基金
Supported by National Natural Science Foundation of China(31070361)
Beijing Outstanding Teaching Team Project about Ecology in 2008
The Fundamental Research Funds for the Central Universities (0910KYZY43)
Undergraduate Research and Training Project of Minzu University of China (URTP201011115)
Quality Course Project of Minzu University of China in 2011
