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

Pseudo-nitzschia multiseries, a neurotoxigenic diatom, was grownin batch culture at light intensities between 53 and 1100 µmolm^–2 s^–1. Cellular contents of carbon. nitrogen andchlorophyll a, and the relationship between photosynthesis andlight levels, were studied during exponential (day 4) and stationaryphases (day 12). In the stationary phase at low light, therewas an increase in cellular chlorophyll a and the initial slopeof P-I curves (^B), which permitted a photosynthetic assimilationof energy equivalent to that of cells grown at high light. Inpast incidents of domoic acid poisoning, this may have facilitateddomoic acid production at low light intensities.