Optinization Of Fermentation Condition Of Producing Elastase And The Property Of Elastase

Elastase is one enzyme that can breakdown indissoluble elastin and elasticin,and it has the ability to breakdown the casein,gelatinum,fibrae sanguis,haemoglobin,albumen and soon.So it is the best tenderization agent.Moreover,elastase can breakdown the ligament,conducting arteries and tendon,it helps to raise availability of meat.Response surface methodology(RSM) is the combination of statistical design experiment technique,it use multielement quadratic equation to fit the functional relation between agents and response value,and through the analysis of regression equation to find the best technology to solve the multi variable questions.The main content of this topic is to study the Bacillus subtilis and it′s ability to produce elastase bases on the different shake flask fermentation cultivation conditions,and to make use of response surface methodology to determine the best fermentation cultivation condition.Meanwhile to study the nature of elastase.First,through the preliminary test to determine the best carbon source is glucose,the best nitrogen source is yeast extract,the best metal ion is K₂HPO₄,KH₂PO₄, MgSO4·7H2O.Secend,through single agent test and double agents duplicate test to determine theserviceable range of glucose,yeast extract,the interaction between glucose and yeast extract,metal ion, temperature,pH and seed volume,and make variance analysis to the agents above.Final,to make use of response surface methodology to design experiment and to obtain the regression equation.To make use of SAS to analyse the regression equation and to obtain the best fermentation cultivation condition:1.5%glucose,1.5%yeast extract, 0.1%K₂HPO₄,0.05% KH₂PO₄, 0.01%MgSO₄·7H₂O,inatial pH is 6.5,the best fermentation temperature is 36.5℃,seed volume is 4%.Through verification test to prove the regression equation is reliable and the parameterr values obtaind are feasible in-service use.Through the study on thermal stability,acid base stability,optimal temperature,optimal pH,metal ion and salting-out of elastase to obtain the conclusion:the elastase produced by this strain has best activity in alky condition:the optimal pH is 8.2 in Tris- HCl,the optimal pH is 7.8 in Na₂B₄O₇·10H₂O-H₃BO₄;the optimal temperature is 50℃,and has best stability below 37℃;metal ion has little influense to activity of elastase;fractional precipitation of elastase is 20%～65%.To make the elastase use on pork and cardiac tube,and find that on the condition of 50℃,4%addition and affect 1h has best tenderization result.