Effects of periodic temperature variation on glycerol fermentation by osmophilic yeast was discussed.At the same time,glycerol fermentation by periodic temperature variation,constant temperature,aerating nitrogen or carbon dioxide during the later stage were compared.The result showed that glycerol yield by periodic temperature variation fermentation was higher than that by constant temperature fermentation and an appropriate temperature oscillatory range was 35-45?℃.During the later stage of constant temperature fermentation,when fermentation time was 72?h,glycerol yield was the highest.After that,glycerol yield began to reduce and glycerol began to be consumed.Then,nitrogen gas or carbon dioxide was sparged in fermentation medium to ferment glycerol unceasingly,which can decrease residual sugar,increase glycerol yield further and avoid glycerol being consumed.Moreover,during the later stage of glycerol fermentation,glycerol yield by sparging nitrogen gas was higher than that by sparging carbon dioxide.
