Photosynthetic performance of freshwater green microalgae Chlorella vulgaris to air-drying treatment

Abstract

Photosynthetic performance in air-dried green microalgae Chlorella vulgaris was investigated. We attempted to identify how air-drying treatment affects chlorophyll a fluorescence OJIP transient and its derived fluorescence parameters. The recorded OJIP fluorescence transients showed a decrease of the variable fluorescence yield at all fluorescence transitions mainly after 4 h treatment compared to measurement at 0 h. The amplitude of the I–P phase from OJIP transient induced by a down-regulation at the PSII level. We suggest that the photochemical state responsible on the variable fluorescence during the first hours (up to 4 h) was maintained by turgid cells. However, the loss of variable fluorescence at sever air-drying treatment was caused by reducing the conversion of light energy in active reaction centers. Furthermore, the performance index (PIABS) parameter used here to quantify the PSII behavior decreased from 0.15 to 0.016 respectively at 0 h and 24 h treatment.