Effects of carbohydrates, amino acids, vitamins, inorganic salts and peptones on the growth of Pasteurella piscicida.

概要

論文の詳細を見る
Pseudotuberculosis caused by Pasteurella piscicida causes a grat loss in yellowtail Seriola quinqueradiata. In order to know growth stimulating factors for the pathogen, the effects of 4 carbohydrates, 20 amino acids, 12 vitamins, 16 inorganic salts and 8 peptones, on the growth of P. piscicida strain U-3 isolated from yellowtail were investigated. Each substance, except peptones, was added individually to the basal medium composed of 1 % polypeptone, 0.5% yeast extract and 2% NaCI. Each peptone was added instead of polypeptone in the basal medium. Bacterial growth was compared by measuring optical density at 660 nm during cultivation.Out of four carbohydrates tested, galactose was the most effective at a concentration of 0.2%. Addition of L-alanine, L-serine, L-asparagine, L-glutamine, sodium L-asparaginate, sodium L-glutamate or L-proline could stimulate growth and among these sodium L-glutamate was the most effective at a concentration of 1.0%. None of the vitamins tested had any stimulative effects. Addition of acetate salts stimulated growth as well. Magnesium acetate was superior than other acetate salts tested and its optimal concentration was 0.5%. Casamino acid was the most effective peptone. Finally, use of casein hydrolysates or soybean meal was capable of growth promoting in comparable beef extract.