The Selection,Identification Of Spoilage Microorganisms In Wine And Optimization, Application Of Culture Conditions For Zygosaccharomyces Bailii

Wine is a kind of nutritional liquor that it is easy to get contaminated by spoilagemicroorganisms.When wine is contaminated by microorganism, it may lead to produce many undesirablephenomenas, such as film production, gas, acid, secondary fermentation. As a result, wine quality willdecrease because of spoilage microorganisms contamination. At the same time, excessive economic losseswill also be brought about. So it is significant to detect and practical application for spoilagemicroorganisms in wine quality control in a fast and, accurate way.We study the spoilage microorganisms on the base of microbial bank from winery enterprise by wayof inoculation experiments. The results showed that the following microbial strains includingY5,Y21,Y25,Y32,Y34,Y35,Y36,Y40,Y44,Y48,Y49,Y50,Y51,B15,B26,B48,B55-63are of potential damage to winequality,and Y40is the spoilage microorganisms which could produce film and isovanillic,which is negativeto wine quality.We make a identification for this strain by physiological,biochemical and as well asmolecular biology method,that is to say using26SrDNA D1/D2. The intergrated consequences show thestrain is Zygosaccharomyces bailii.We detected the content of physical and chemical indicators, aromacomponents, biogenic amines and ethyl carbamate for the wine with Y40.The results showed that it only hasinfluence on aroma components.As advanced method for rapid detection needs sophisticated scientific instruments,complexoperation,and it also require a higher quality of personnel.While medium have been widely used inscientific research and fermentation as it is cheap, easy to operate. So we focused on medium.We comparedTGYA and ZBA,and found that ZBA is more specificity.It found that Zygosaccharomyces bailii has thehighest growth rate in condition of Sabouraud dextrose agar,45g/L; NaCl,0g/L; pH3; potassium sorbate,0%; acetic acid,0.1%; trypan blue,0g/L;25℃when we take a single factor experiment for ZBA. Weimplemented an orthogonal optimization for Sabouraud dextrose agar, NaCl and trypan blue.And the resultshow that Zygosaccharomyces bailii has the highest growth rate and shortest time when the condition isSabouraud dextrose agar,65g/L; NaCl,0g/L; trypan blue,0g/L.Compared to ZBA,the growth rate ofoptimized medium rose from18.79％to87.80％,and the growth time is reduced to39h from139h.Similarly, the specificity of optimized medium is strong.The optimized medium is cheaper and easier tooperate, and it is of great potential to be used for winery applications.When the wine contaminated by spoilage microorgannisms,one side,we need to take action to protect it from loss,and on the other side,we need to know the distribution of spoilage microorganisms in theprocess of wine production so that we coud take steps for pollution prevention.We detected the process ofwine production using optimized medium ZBA,and the result showed that Zygosaccharomyces bailiiexisted in various stages of winemaking process, wine grapes, workshop environment and brewingequipment.However, the quantity is changed with living environment.