Acclimation to low light intensity in photosynthesis and growth of Pseudo-nitzschia multiseries Hasle, a neurotoxigenic diatom

Pseudo-nitzschia multiseries, a neurotoxigenic diatom, was grown in batch culture at light intensities between 53 and 1100 mu mol m(-2) s(-1). Cellular contents of carbon, nitrogen and chlorophyll a, and the relationship between photosynthesis and light levels, were studied during exponential (day 4) and stationary phases (day 12). In the stationary phase at low light, there was an increase in cellular chlorophyll a and the initial slope of P-I curves (alpha(B)), which permitted a photosynthetic assimilation of energy equivalent to that of cells grown at high light. In past incidents of domoic acid poisoning, this may have facilitated domoic acid production at low light intensities.