| Recirculation of the water of fish rearing systems requires a biological treatment based on the nitrifying activity of autotrophic bacteria. In parallel heterotrophic bacterial populations utilise the organic substrate, produced by the fish, to grow. Opposite to the autotrophic populations, the heterotrophic bacteria (1) have a quick growth and (2) might contain fish pathogenic strains. The main aim was to characterise the heterotrophic bacteria populations ?.nd to understand (1) which parameters do control the dynamics of their populations and (2) their influence on the quality of the recirculating water. In a rearing system, the heterotrophic bacterial populations are stable in number and in genus, for a given operating mode. The bacteria are either... |
