Evaluation of the primary reactions of photosynthesis in microalgae single cell by microfluorimetric method

High-resolution chlorophyll fluorescence light induction curves (OJIP transients) are widely used to assess the primary photosynthetic responses of phototrophic microorganisms. Chlorophyll fluorescence measuring methods coupled with microscopy techniques provide a promising opportunity to measure OJIP transients on individual algal cells, allowing scientists to investigate stress adaptation mechanisms related to reorganization of microalgae population or phytoplankton community. In this work, we first characterized the OJIP transients measured on individual algae cells using the original microfluorimeter and compared them with OJIP transients recorded in microalgae suspensions. Based on the results of the study, we proposed a method for analyzing OJIP curves of individual microalgae cells as well as ways to further improve microfluorimeters.