STUDIES ON THE NUTRITION OF PASTEURELLA TULARENSIS

Abstract

tularensis can be cultured on blood-peptone agar enriched with cysteine, subsequent work (Rans-meier and Schaub, 1941; Ransmeier and Stekol, 1942; Steinhaus, Parker, and McKee, 1944; Larson, 1945) reemphasized the high demand for cysteine or cystine as the most characteristic nutritional feature of this microorganism. The study of Berkman (1942) appears to be the first attempt aimed at the elucidation of the basic nutritional requirements of P. tularensis. Using a gelatin hydrolyzate fortified with several amino acids as a basal medium he demonstrated the need for thiamin or cocarboxylase as an es-sential growth factor. Tamura and Gibby (1943) and Gibby et al. (1948) were able to grow P. tularensis in liquid media composed of protein hydrolyzates or an amino acid mixture supplemented with an ex-tract of blood cells. Mills et al. (1949) in a brief communication reported that good growth of a highly virulent strain of Bacterium tularense was obtained in a medium containing casein hydrolyzate, glucose, cysteine, salts, and 0.1 per cent decamin (a dried yeast autolyzate). The casein hydrolyzate could be replaced by a mixture of amino acids. Tamura and Fleming (1949) in a preliminary report announced the cultivation of B. tularense in a synthetic medium with cocarboxylase, adenylic acid, adenosine diphosphate, or adeno-sine triphosphate as the critical growth factors. No experimental data were presented. With the strains at our disposal we were un-able to obtain growth in the semisynthetic or synthetic media described in the literature. In a preliminary communication (Mager, Traub, and Grossowicz, 1954) the factors determining growth of P. tularensis in chemically defined media have been discussed. In the present paper results of a