Abstract: The optimal impurity removal technology of waste beer yeast paste is determined as removing the impurity by twice sieving the waste beer yeast paste with the yeast concentration of 8% at 80 meshes. Based on the above technology,after using 5% tartrate to debitter for 30 min,the yields of the purified beer yeast cells from four kinds of waste beer yeast paste (whole barley,adjuvant,wheat and rye) are up to 23%～46%. Through orthogonal test,the optimal technological conditions for extrcting RNA from the purified beer yeast cells by salt fractionation at high temperature are determined as follows: extraction time 5 h,temperature 100 ℃,concentration of yeast 4% and concentration of NaCl 12%. The extraction rate of RNA reaches 13.8%.

Key words: waste beer yeast paste, RNA, extraction