Effect of Light Quality and Nitrogen Availability on the Biomass Production and Pigment Content of Palmaria palmata (Rhodophyta)

Abstract

Macroalgae constitute a huge underexploited resource for compounds of interest to the health industry. External factors strongly influence the concentration of these compounds in the algal tissue. This implies a potential for optimizing the growth conditions for cultivated macro algae in order to promote production of valuable compounds. The objective of this study was to determine the influence of light spectralcomposition (red, blue, and white) and nutrient treatment (30 and 440 µM NO₃^-) on chlorophyll a andcarotenoid concentration as well as growth rate of the red algae Palmaria palmata. The results show that the nitrogen load has a larger effect on the pigment concentration and growth rate in the algae, than the light treatments. Experiments with different light spectral composition showed the highest pigment content with white and blue light while red light was less effective. In addition, samples cultivated under white light had higher growth rates compared to red and blue light. Therefore, to increase the concentration of nutritionally valuable pigments cultivation strategies in marine production should be to use blue or whitelight and use high NO₃^- concentrations.