Adaptation of phytoplankton to novel residual materials of water pollution: an experimental model analysing the evolution of an experimental microalgal population under formaldehyde contamination.

The adaptation mechanisms of microalgae to grow in contaminated waters were analysed using a chlorophyta species under formaldehyde exposure as experimental model. Cultures initially collapsed after exposure to 16 ppm formaldehyde, but occasionally resistant cells were able to grow after further incubation. Resistant cells arose by rare spontaneous mutations that appeared before the exposure to formaldehyde (mutation rate=3.61 x 10(-6)), and not as result of physiological mechanisms. Although mutations may be the mechanisms that should allow the survival of microalgae in polluted waters in a world under rapid global change, mutants have a diminished growth rate.