【作者】 张珍；

【导师】 韩舜愈；

【作者基本信息】 甘肃农业大学 ， 农产品加工及贮藏工程， 2013， 硕士

【摘要】 酵母菌株对葡萄酒色泽、香气、感官质量和风格的影响极为重要，然而我省葡萄酒生产所用酵母菌大部分来自进口，使葡萄酒出现了“同质化”的倾向，同时，进口活性干酵母的使用会降低酵母多样性和本土酵母作用的重要性，为此，急需对甘肃河西地区葡萄酒产业基地的野生酿酒酵母菌的本土资源进行研究和保护。本试验以成熟葡萄浆果为研究对象，利用YEPD培养基从自然发酵的葡萄汁中进行葡萄酒相关酵母菌株的分离，利用WL营养培养基、形态学及生理生化试验进行初步分离鉴定，并筛选耐受性能较强的菌种作为种质资源保存，同时对部分菌株进行26S rDNA D1／D2区测序，然后选取耐受性较好菌株进行产香能力比较，得到研究结果如下：1．根据WL营养培养基培养上群落差异，初步得到10个酵母遗传聚类群：红酵母属、梅奇酵母属、接合酵母属、酵母属、路氏类酵母属、毕赤酵母属、假丝酵母属、有孢汉逊酵母属及其它2类酵母属。2．耐受性试验结果表明，菌株WLFE、WLFEC-3、WLFM-6、ZXFS、MGFEC-1、MGFEH-3、MGFM-7能耐受18%酒精浓度；菌株WLFE、WLFEC-3、WLFM-6、QLFS-4、MGFEC-1、MGFEH-3、MGFM-7能耐受50%葡萄糖浓度；菌株WLFE、WLFM-6、MGFEH-3、MGFM-7能耐受18％NaCl；菌株WLFE、WLFEC-3、ZXFS、MGFM-7能耐受pH2.5酸性环境；WLFE、WLFEC-3、WLFM-6、ZXFS-6、QLFS-4、MGFEC-1、MGFEH-3、MGFM-7能够耐受12℃低温；菌株WLFE、WLFEC-3、MGFM-7能耐受250mg/LSO2浓度。3．供试菌株经26S rDNA基因序列测序结果表明，属于5个属6个种，分别为：Metschnikowia aff，Rhodotorula slooffiae，Saccharomyces cerevisiae，利用WL营养培养基无法鉴定的类型经26S rDNA基因序鉴定为Sporobolomyces roseus属于郑孢酵母属，Cryptococcus flavescens、Cryptococcus magnus属于隐球酵母属。4．通过对4款酒样香气成分的分析发现，接种MGFM-7菌株的酒样有27种香气化合物，接种WLFEC-3菌株的酒样有11种香气化合物，接种ZXFS和WLFE菌株的酒样各有8种香气化合物，说明菌株MGFM-7可以产生较多种类香气化合物，有利于丰富酒体的口感。但有关该产区酵母菌的发酵特性及其利用价值还需做进一步研究。更多还原

【Abstract】 Yeast strains have a significant effect on wine color, aroma, sensory quality and style,however, yeasts that used in the production of wine are mostly from imports in Gansuprovince, appearing a "homogenization" tendency. At the same time, the use of importedactive dry yeast can reduce the importance of yeast diversity and the role of indigenous yeast,therefore, a need of research and conservation for local wild yeast resources of the wineindustrial base in Hexi region is carried out urgently. In this experiment, ripe grape berries asobject of study, the use of YEPD medium for isolation of wine-related yeast strains from thespontaneous fermentation grape juice, WL nutrient medium, morphological, physiological andbiochemical tests were used initially for isolation and identification, from which the strongtolerance performance strains were screened as germplasm resources and conserved.Meanwhile some strains were identified by26S rDNA D1/D2region sequencing, and then thestrains with better tolerance were used to compare the capability of producing aroma. Theresults were as follows:1. Based on the colony differences on WL nutrient medium,10yeast genetic clusteringgroups were obtained preliminaryly: Rhodotorula, Metschnikowia, Zygosaccharomyces,Saccharomyces, Saccharomycodes ludwigii, Pichia, Candida, Hansenula and other two kindsof yeasts.2. Tolerance test results showed that strains WLFE, WLFEC-3, WLFM-6, ZXFS,MGFEC-1, MGFEH-3, MGFM-7can withstand a ethanol concentration of18%; strainsWLFE, WLFEC-3, WLFM-6, QLFS-4, MGFEC-1, MGFEH-3, MGFM-7can withstand theglucose concentration of50%; strains WLFE, WLFM-6, MGFEH-3, MGFM-7can withstand18%NaCl; strains WLFE, WLFEC-3, ZXFS, MGFM-7can withstand the acidic environmentof pH2.5; WLFE, WLFEC-3, WLFM-6, ZXFS-6, QLFS-4, MGFEC-1, MGFEH-3, MGFM-7can withstand low temperature of12℃; strains WLFE, WLFEC-3, MGFM-7can tolerate250mg/L of SO2.3. Strains tested by26S rDNA gene sequencing results showed that belong to6speciesof5genera, respectively: Metschnikowia aff belonging to Metschnikowia, Rhodotorula slooffiae belonging to Rhodotorula, Saccharomyces cerevisiae belonging to Saccharomyces.The strains that not be able to be identified by WL nutrient medium were identified by26SrDNA gene sequencing: Sporobolomyces roseus belonging to Sporobolomyces,Cryptococcus flavescens and Cryptococcus magnus belonging to Cryptococcus.The analysis of aroma components from4wine samples showed that the wine sample which inoculated MGFM-7strain was found27kinds of aroma compounds, WLFEC-3strain11kinds, and the samples inoculated strains ZXFS and WLFE had eight kinds of aroma compounds, respectively. So strain MGFM-7can produce more kinds of aroma compounds and helpenrich the taste of wine. But the yeast fermentation characteristics and its values in use of thisregion need to do further research.更多还原