The Associative Action Between Certain Yeasts and Bacterium Linens

Abstract

Summary The data reported herein support the hypothesis that the yeasts of limburger cheese contribute to the growth of Bacterium linens by decreasing the acidity of the curd and by simultaneously secreting required growth factors. The presence of a yeast is required for growth of all B. linens strains in a vitamin-sufficient medium adjusted to pH 5.0 but not in the same medium adjusted to pH 6.5. A majority of the yeasts possess this growth-promoting ability. The presence of a yeast is required for the growth of vitamin-dependent B. linens strains in a vitamin-free medium adjusted to pH 6.5 unless pantothenic acid is present. All of the yeasts possess growth-promoting ability under these conditions. All of the yeasts secrete appreciable amounts of pantothenic acid, riboflavin and niacin.