Abstract
Isolation and purification of protein from the dried cells of a species of yeast (genus Candida) which had grown on n-paraffin was studied with the purpose of utilyzing it as human food.
Dialysis of the alkali extract from the dried cells against water was effective to eliminate an odor particular to the yeast cells of this kind. A part of cell wall substances of the yeast extracted into the alkali solution was precipitated by the dialysis against water while the extracted proteins stayed in solution. Thus, the dialysis of the alkali extract against water played double roles, the elimination of the odor and the removal of cell wall substances.
Ethanol fractionation of the dialyzate revealed that about 40% of the protein in the dialyzate could be precipitated between the ethanol concentration of 20-30%. Addition of calcium chloride into the dialyzate and following second dialysis of the solution against water resulted in precipitation of a protein fraction of higher purity. After removal of this high pu ity protein fraction more protein could be obtained from the supernatant fraction by ethanol precipitation.
An example of protein isolation from the dried cells by the combination of those procedures is presented. Those simple procedures may be useful for preparing protein of high quality in large scale.
