Shaking of the samples

30 ml PP nutrient solution and 156 μl antibiotic solution (0.2% Penicillin, 2% Streptomycin, 1% Nystatin) is added into each glass, then it is inoculated with 600 μl 6 days old homogenous Tetrahymena culture. The glasses are shaken at 100 rpm, at room temperature (20-25 °C), in the darkness.