Quantification of pyoverdin produced in food by Pseudomonas and increase of aspartate amino transferase after pyoverdin ingestion in mice

Pyoverdin was purified from Pseudomonas fluorescens cultures and its fluorescent spectrum was compared with those observed with pyoverdin extracted from chicken meat and cottage cheese. Pseudomonas was the most frequent genus amongst Gram-negative bacteria capable of growing on meat and cottage cheese surface. Dairy products reached counts higher than the values observed in chicken meat for psychrotrophes and Pseudomonas. Relations between pyoverdin production and psychrotrophes or Pseudomonas counts were established. Pigment amounts on surface correlated with Pseudomonas counts. Contamination on surface of cottage cheese was higher than into the deep layers. In these, the amount of pyoverdin detected correlated with surface instead of deep layer Pseudomonas count. The amount of pyoverdin needed to increase aspartate amino transferase (AST) of mouse liver to a significant degree exceeded the amounts found in food.