Experimental Studies on the Formation of Volatile Nitrogen Compounds Induced by Pseudomonas Fragi in A Synthetic Medium with Amino Acids as Source of Nitrogen
Acta Veterinaria Scandinavica
FLORIN, S. 0. : Experimental studies on the formation of volatile nitrogen compounds induced by Pseudomonas fragi in a synthetic medium with amino acids as source of nitrogen. Acta vet. scand. 1972, 13, 403-434. -The influence of the growth of Pseudomonas fragi strain FIll was studied in a synthetic medium. It was shown that volatile nitrogen compounds were rapidly liberated as a result of the decomposition at 5°C of arginine and histidine. A later and slower incr ease of TVN was ob served in
... was ob served in media, which contained lysine or urea. From the other 7 amino acids which were included in the test, no increase of TVN was observed to be caused by the strain FIll. It was shown that within the range of 0.05 to 0.8 % histidine added to the basic salt solution the amount of TVN liberated was correlated to the amount of histidine included in the media. At the TVN maximum approx. 50 % of the amino acid nitrogen of the med ium was recovered as TVN. It was further shown that the liberation of TVN was correlated to the added amount of arginine and histidine included in the growth medium. The presence of lysine also influenced on the TVN maximum which was reached. In the synthetic medium to which arginine or histidine was added the growth of strain FIll was stimulated by the presence of glucose. The acids produced by the oxidative breakdown of glucose were neutralized partly by the volatile bases produced in the decomposition of amino acids. The ability of the Pseudomonas fragi to grow in anaerobic conditions and to produce enzymes which could de compose histidine was studied. It was concluded that the anaerobic breakdown of histidine was similar to the anaerobic breakdown of arginine reported by other authors. v 0 I a til e nit r 0 g e nco m p 0 un d s ; P s e u d 0 m 0 n a s f r a g i; s y nth e tic me diu m; ami n 0 -a c i d -b I' e a k dow n.