Breeding of Saccharomyces cerevisiae with high ethanol tolerance and its application in kiwi wine

A strain of HJ-1 with ethanol tolerance yeast strain was selected as the test strain which was screened from the fruit and soil of each county orchard surrounding Hohhot,kiwi fruit was as raw materials,the kiwi fruit wine fermentation process was investigated.After UV mutagenesis,the positive mutant yeast strains were selected by four screening including TTC screening and Duchenne tubule screening,then applied to kiwi fruit wine fermentation.The effects of fermentation temperature,the strains inoculation quantity and initial pH on the quality of kiwi fruit wine were studied by single factor and orthogonal test.The results showed that a high ethanol-resistant mutant strain HJ-1E was screened by UV mutagenesis,and its ethanol tolerance was 18%vol,with alcohol production capacity of 11.9%vol.The optimum conditions for the production of kiwis fruit were the inoculation amount of the strain was 3.5%,the initial pH was 5.7,the amount of SO₂ was 70 mg/L and the fermentation temperature was 21℃.Under this condition,the kiwi fruit wine fermented by HJ-1E was of rich and mellow flavor and its alcohol content was 13.3% vol,it would provide reference for the production of kiwi fruit wine.