Isolation,purification and identification of high temperature halophilic yeast from soy sauce Mash

In order to improve the flavor of the industrial production of soy sauce,we isolated and screend high temperature halophilic yeast from fermented soy paste of the traditional craft of Liaoning Province.By analyzing morphological,physiological and biochemical characteristics and 26S rDNA sequence to determine its taxonomic status.The screening strain was Zygosaccharomyces rouxii.Experiments showed that the screening strain had good growth in the NaCl mass concentration of 17%,and fermentation temperature of 45℃ solution environment and it was very suitable for the industrial production of soy sauce fermentation process.By the aroma of comparative experiments showed that total nitrogen and amino nitrogen content had a certain increased in added screening strain and amino acids generation rate reached to 52.94% in 32nd experiment days .Associated with headspace solid phase micro extraction (HS SPME),gas chromatography mass spectrometry(GC-MS) to analyze volatile constituents in soy paste,about 7 major types of volatile substances,a total of 48 species were isolated from the soy paste.Compared with Angel Yeast,JY-7 was significantly better than Angel Yeast.Therefore the screening strains could be used as flavoring yeast to add to the ripening process of the production of soy sauce,so as to improve the flavor of soy sauce.