Cultivation of Pasteurella haemolytica in a Chemically Defined Medium

A chemically defined medium was developed for the aerobic cultivation ofPasteurella haemolytica . Studies on the growth of strain H44L were conducted in a medium consisting of 15 amino acids, inorganic salts, citrate, nicotinamide, pantothenate, thiamine or thiamine monophosphate, and carbon sources. The amino acids were provided asl isomers, because racemic mixtures of some amino acids inhibited growth. The carbon source consisted of a mixture of 1.0%d -galactose and 0.1%d -glucose. Culture populations of strain H44L reached 2 × 1010 cells per milliliter after 16 hr of incubation at 37.5 C. Other strains ofP. haemolytica , from a wide variety of sources, were tested for growth in the medium, and 23 of 24 strains grew well. Five strains ofP. haemolytica var.ureae failed to grow in the medium.