地参发酵酒中专用酵母菌的筛选、鉴定及特性研究

Screening,Identification and Characteristics of Special Yeasts in Lycopus Lucidus Brewed Wine

为筛选地参发酵酒专用酵母菌,以地参自然发酵液、地参表皮及地参根际土壤为材料进行酵母菌的分离纯化,通过杜氏管发酵法、产酒精能力及耐酒精和SO2能力三级筛选得到1株地参发酵酒专用酵母菌。采用WL营养琼脂培养基和26S rDNA Dl/D2区序列对筛选得到的菌株进行鉴定,并对其生长特性及耐受性进行研究。结果表明:从3种分离源中得到35株酵母菌,其中地参自然发酵液的3个发酵时期中共得到24株酵母菌(发酵前期8株、中期11株、后期5株)、地参表皮中得到4株酵母菌、地参根际土壤中得到7株酵母菌,通过三级筛选,得到1株地参发酵酒专用的酵母菌DY9;通过形态学鉴定菌株DY9在WL营养琼脂培养基上颜色为奶油色带绿色,在显微镜中细胞形态为椭圆形,经26S rDNA D1/D2区序列鉴定DY9菌株为酿酒酵母菌(Saccharomyces cerevisiae);研究发现DY9菌株最适生长温度为28℃,最适生长p H值在5左右,葡萄糖、SO2及酒精耐受浓度分别为250 g/L、230 mg/L和12%。地参自然发酵液、地参表皮及地参根际土壤中酵母菌资源丰富,筛选出的酿酒酵母DY9具有良好的生长特性,可为后期地参发酵酒的发酵提供菌株支持,对促进地参产业发展具有一定的实用价值。

In order to select the special yeast for Lycopus lucidus brewed wines,the natural fermentation liquid,surface,planting soil of Lycopus lucidus were used as the separation sources to isolate and purify the yeast.After Duchenne tube fermentation,alcohol,the capacity of product alcohol,and sulfur dioxideresistant screening,one yeast strain for Lycopus lucidus brewed wines was obtained.The screened strains were identified by WL nutrient agar medium and 26S rDNA D1/D2 sequence,and their growth characteristics and tolerance were studied.The results showed that 35 yeast strains were obtained from three sources.Among them,a total of 24 strains of yeast were obtained during the three fermentation periods of the natural fermentation liquid of Lycopus lucidus(8 strains in the early stage,11 strains in the middle stage,and 5 strains in the later stage),4 strains of yeast were obtained in the epidermis of Lycopus lucidus,7 strains of yeast were obtained from the rhizosphere soil.Through three-stage screening,one strain of yeast DY9 special for brewed wine of Lycopus lucidus was obtained.By morphological identification,the color of strain DY 9 is cream colored with green on WL nutrient agar medium,and the cell shape is oval under the microscope.Strain DY 9 is identified as Saccharomyces cerevisiae by 26S rDNA D1/D2 sequence.The results showed that the optimum growth temperature of DY 9 strain was 28℃,the optimum growth pH value was 5,the glucose tolerance concentration was 250 g/L,the SO2tolerance concentration was 230 mg/L,and the alcohol tolerance concentration was 12%.The natural fermentation broth,epidermis and rhizosphere soil of Lycopus lucidus are rich in yeast resources.The selected Saccharomyces cerevisiae DY 9 has good growth characteristics and can provide strain support for the fermentation of Lycopus lucidus brewed wine,and has certain practical value in promoting the development of Lycopus lucidus industry.