Variation of Cell Wall Content in Flocculent and Non-Flocculent Yeast Strains

Estimation of the wall content of a number of flocculent and non-flocculent yeast strains taken in both the growth and stationary phases reveals that flocculent yeasts almost invariably increase their wall content to a greater extent as the cells pass to the stationary phase than do non-flocculent strains. This variation of increase is observed whether the yeasts are grown in hopped wort or in a synthetic malt-yeast-peptone-glucose medium. There are considerable variations in wall content from strain to strain in both types of yeast. Cells of flocculent strains are more difficult to disrupt than those of powdery strains. The nitrogen, phosphate and carbohydrate contents of the walls of all strains varied between the growth and stationary phases but no significant trends were noted in any of the components which could be related to flocculent or non-flocculent behaviour.