Screening And Identification Of High Producing β-glucosidase Wild Non-saccharomyces Yeasts Strain From Jiyuanand Changli

Beta-glycosidase enzymes play important role in the field of flavoured wine that havebeen proved by many research institutes. However, in the production of wine the source ofenzyme preparations are mostly imported that lead to the production cost is very high. In thewine production of each link such as trees, soil, grape vineyard containers and brewingequipment, also environment have all kinds of yeast which have different kinds of yeastswith different morphology, physiological and biochemical characteristics, and high betaglycosidase enzymes strains may exist in. From jiyuan of henan province and changli ofhebei province wine production in every link of screening, this study would screed highbeta glycosidase enzymes of saccharomyces cerevisiae, determine methods of screening ofhigh yield enzyme strain at the same time in order to provide the basis for efficientscreening of high yield and enzyme strains.1. From region of Jiyuan and Changli that the main producing area of China,189yeaststains were separated from natural fermentative grape juice. The first screening was carriedout using aesculin developing technology. The second step was to determine glucosidaseactivity in the crude enzyme solution from selected stains. The glucosidase activity ofhydrolyzing p-NPG was determined with the absortance in400nm. Finally, the strains withhigh activity of glucosidase were identifided by morphological, physiological, biochemicaland molecular methods. The results showed that eight non-Saccharomyces cerevisiae strainswere selected for their higher activity of glucosidase from189yeast strain from Changli ofHebei province and Jiyuan of Henan province. The “Ji13”are the best high producingβ—glucosidase strains and higher than “Ji45” and “Chang29”. The enzyme activity hassignificant difference（p＜0.05）. They were42.51×10-3U/ml，36.14×10-3U/ml and35.9×10-3U/ml, respectively. 2. Through morphological identification and physiological and biochemical test, PCRamplification products with BLAST comparing DNA sequences, Chang “29”, Ji “45”and“13” were identificated. The results showed that there is similarity of26srdna conservativesequence is about99%between Chang “29” and red yeast of Rhodotorula mucilaginosa.Ji “45” and yeast of Clavispora lusitaniae26srdna conservative sequence are similarityahout99%. Ji “13” and yeast of Pichia membranifaciens26srdna conservative sequenceare similarity ahout100%. So “Ji13” was identified as Pichia membranifaciens.“Chang29” was identified as Rhodotorula mucilaginosa and “Ji45”was identified as Clavisporalusitaniae.