Abstract:The protective effect of glycerol, one of the compatible solutes, on Zygosaccharomyces rouxii in high osmotic pressure condition was studied and the growth of Z. rouxii was observed in 3 mol/L NaCl YPD mediums with different concentrations of glycerol. Z. rouxii and glycerol were co-immobilized and applied to the fermentation of high salt diluted-state soy sauce mash. The results indicated that, 1.37 mmol/L glycerol can relieve the inhibitory effect caused by high salinity on the growth of Z. rouxii efficiently, the lag phase in growth curve of Z. rouxii was shorten by 4~6 hours. Compared with the control group, the protein conversion rate of pilot-scale fermentation of soy sauce was increased by 2.23~5.64%, and the fermentation period of soy sauce was shorten by 15 days on average. It was concluded that glycerol could protect Z. rouxii under the high-salt conditions, and improve the metabolism rate of Z. rouxii in the fermentation of high salt diluted-state soy sauce mash. Co-immobilized glycerol with yeast can improve the utilization rate of raw materials and shorten the fermentation period, showing practical application potencial in soy sauce brewing.
