Nutritional factors influencing the polysaccharide production of Brucella suis.

The formation of cellular polysaccharide by cells of the genus Brucella has been reported by several investigators: Favilli and Biancalani (1934), Higginbotham and Heathman (1936), and Libby and Joyner (1941). These workers, however, dealt mainly with the immunological characteristics of the polysaccharide, and little emphasis was placed upon the nutritional conditions affecting its production. A comparison of the differences in the media with the chemical characteristics of the polysaccharide material isolated from Brucella abortus, Brucella suis, and Brucella melitensis by Huston et al. (1934) and Higginbotham and Heathman (1936) suggests that nutrition may play an important role in the synthesis of polysaccharide by this group of organisms. Investigations in this laboratory with B. suis revealed certain nutritional conditions which significantly altered the polysaccharide content of this organism. The data suggest that this polysaccharide was intracellular and therefore probably unrelated to the immunologically active fractions studied by others. The following presentation is concerned primarily with identification of the nutritional conditions affecting polysaccharide formation. The isolation and chemical characterization of the polysaccharide will be reported later.