The Isolation And Identification Of Microorganism In North Yellow Millet Wine Wheat Starter And The Characteristics Research Of Quality Strains

Yellow millet wine is a kind of Chinese traditional brewing food, which has a long history. The wheat starter which made by wheat were used in brewing of yellow millet wine, as saccharifying agents and leavening agents. With the adding of wheat starter,the microorganisms will enter the rice wine, so the wheat starter has a very important impact on taste and flavor of the wine. Therefore, the study on identification, classification and feature of wheat starter microbial can provide a theoretical basis for brewing rice wine, and has a positive effect on the inheritance and protection of the traditional brewing process and taste of north yellow millet wine.In this research, we use MRS medium combined with dilution and crossed purification method, and the wheat starter bacteria were isolated and purified. We Used morphological analysis to a preliminary classification of bacteria, and the 16SrDNA sequences were obtained by molecular biology methods. Six different sequences were received in total, and this six bacteria were identified as Bacillus subtilis, Bacillus licheniformis and Bacillus cereus. The study on characteristics in growth curve, pH endurance, high-alcoholicity endurance and the use of glucide of the six bacteria showed that, the range of endurable pH is 4.0 to 11.0 and these six bacteria could endure 10%(v/v)alcoholic strength, WSB-1 and WSB-6 had the strongest alcoholicity endurance.We isolated the moulds by using Wort medium and Czapek’s medium, and We Used morphological analysis to a preliminary classification of moulds, and the 5.8SrDNA-ITS sequences were obtained by molecular biology methods. The moulds were identified as Lichtheimia ramosa, Aspergillus oryzae, Penicillium purpurogenum, Aspergillus versicolor, Alternaria mali. The study on characteristics in pH endurance and high-alcoholicity endurance of mould showed that, the WSM-1,WSM-2 and WSM-4 has the better acid endurance, and they can survive when pH were 4.0. WSM-4 has the widest pH resistance range. The high-alcoholicity endurance of 5 moulds is weak, when the volume fraction of 5%(v/v)alcohol, the moulds stop growing.The yeast were isolated by Wort medium, and the WL medium combined with morphology were used for the preliminary classification of yeast. The restriction enzyme HinfⅠ and HaeⅢ were used for digested the 5.8SrDNA-ITS sequences which were obtained by molecular biology methods. The results showed that only one strain of yeast were obtained, and it were identified as Saccharomyces cerevisiae. The study on characteristics in pH endurance, high-alcoholicity endurance, the use of glucide and the generating of esters of the six bacteria showed that, the yeast cells multiply very fast, endurable pH is 4.0, the high-alcoholicity endurance is 12%(v/v), can produce esters, and has the ability to produce acid and carbon dioxideby utlizing glucose, maltose, sucrose and fructose.