In vitro nutritional requirements and metabolic products of pathogenic and nonpathogenic strains of Cryptobia salmositica: essential carbohydrates and amino acids.

Abstract

Pathogenic and nonpathogenic strains of Cryptobia salmositica cultured in minimum essential medium (MEM) with several monosaccharides, disaccharides and amino acids were observed for differences in multiplication and motility. Metabolic end products (i.e. alanine, aspartate, carbon dioxide, lactate and pyruvate) were measured for logarithmically growing cells under aerobic conditions. The pathogenic strain of C. salmositica multiplied more readily in MEM supplemented with D(-)ribose, D(+)xylose, D(+)galactose, D(+)glucose, D(+)mannose and D(-)fructose. However, there were no significant differences in multiplication when the strains were cultured with the monosaccharide D(-)arabinose. The nonpathogenic strain multiplied significantly better than the pathogenic strain in the presence of the disaccharides alpha-lactose, maltose and sucrose. It also multiplied more readily when the amino acids L-glutamine and D(-)proline were added to MEM. The end products of carbohydrate catabolism under aerobic conditions were alanine, aspartate, carbon dioxide, lactate and pyruvate.