Variability of Chlorella sp. fluorescence in response to different nitrogen conditions
Abstract:The variability of quantitative fluorescence characteristics of Chlorella sp. (strain TV217) pigments during culture growth under different nitrogen conditions was studied by using excitation spectra of in vivo fluorescence. The ratio of chlorophyll-b/chlorophyll-a , calculated for both concentration and fluorescence levels, was stable for the selected culture and depended weakly on the environmental conditions and growth phase. However, the relative fluorescence efficiency of chlorophylls and chlorophyll-a-specific fluorescence in culture with inorganic additions showed the lowest values at the exponential phase of growth. Chlorophyll-a-specific fluorescence, investigated in field experiments on natural phytoplankton, showed a similar pattern. Generally, the chlorophyll-a-specific fluorescence was two to five times less during intensive growth of the community compared with the stationary stage. The possibilities of using fluorescence for quantitative calibration of phytoplankton pigment content are discussed.
Document Type: Research Article
Publication date: January 20, 2001