Research On Alcohol Fermentation Of High Fermentation Degree Saccharomyces Cerevisiae Engineering Strain SSF Method

Alcohol is widely used in biological energy,industrial,pharmaceutical and food industries,although the fermentation of alcohol has a long history in our country,but alcohol production technology still lag behind the advanced countries such as America,Brazil.In order to improve the production of alcohol and equipment utilization,reduce the production cost of alcohol,the fine wine yeast is the key.At the same time in the fermentation process,SSF method for simple process,energy saving,short fermentation cycle is becoming the trend of alcohol fermentation industry.In this study,we study on the alcoholic fermentation of saccharomyces cerevisiae engineering bacterium 267G.First of all,we studied its growth characteristics,fermentation performance,tolerance,and through the method of sodium iodate to determine the capacity of saccharifying enzyme of 267#fermentation broth.And the same time,using single factor method to determine the 2671 high density culture optimum condition,on the basis of single factor optimization results compared the effects of three kinds of way of adding glucose on bacterial density.We used refined corn flour as raw materials to SSF alcohol fermentation for 267#,Fermentation with refined corn flour as raw materials,the strain 267#SSF alcohol fermentation,using Plackett-Burman design combined with response surface analysis method to determine the best alcohol fermentation production.The experimental results show that the initial sugar concentration is 24%,alcohol production capacity of strains can reach 14.5%,And strains can tolerate glucose 45g/100mL,24%ethanol,pH2.5,NaC12 120g/L,saccharifying enzyme producing ability of 0.432U/mL.The optimum conditions for strain high density cultivation is glucose 4g/100 ml,glycine 0.1g/100 ml,shake the bed 100r/min,among the three kinds of carbohydrate supplement trials,once carbohydrate supplement method is themost favorable for high density cultivation,number of living bacterium is 2.4 x108 cfu/mL,was 3.7 times before optimization.Single factor experiment combined with response surface analysis determined the optimum conditions of 267#SSF alcohol fermentation is 34??fermentation time 66 h?Cultivating base water than 0.51?urea 0.59g/100mL?inoculum size 13.07%?MgSO4 0.033g/100mL?KH2PO4 0.023g/100mL?CaCl20.013g/100mL?pH5.5?saccharifying enzyme 103U/g,Produced alcohol concentration up to a maximum of 14.06 mL/100 mL,increased by 22.47%than before optimization.If the strain will be applied to industrial alcohol fermentation,can greatly save cost of saccharifying enzyme.