Although the toxic activity of B. sphaericus SSII-1 was relatively unchanged throughout growth, an increase in activity of strain 1593 occurred as the bacteria began to sporulate. ###>Bien que l'activité toxique de B. sphaericus SSII-1 demeure relativement la même au cours de sa croissance, celle de la souche 1593 augmente dès que la bactérie commence à sporuler.