Comparison between fluorimetry and oxymetry techniques to measure photosynthesis in the diatom Skeletonema costatum cultivated under simulated seasonal conditions - Archive ouverte HAL
Article Dans Une Revue Journal of Photochemistry and Photobiology B: Biology Année : 2007

Comparison between fluorimetry and oxymetry techniques to measure photosynthesis in the diatom Skeletonema costatum cultivated under simulated seasonal conditions

Résumé

This study reports comparison of two techniques measuring photosynthesis in the ubiquitous diatom Skeletonema costatum, i.e., the classical oximetry and the recent modulated fluorimetry. Microalgae in semi-continuous cultures were exposed to five different environmental conditions simulating a seasonal effect with co-varying temperature, photoperiod and incident light. Photosynthesis was assessed by gross rate of oxygen evolution (PB) and the electron transport rate (ETR) measurements. The two techniques were linearly related within seasonal treatments along the course of the P/E curves. The light saturation intensity parameters (Ek and ), and the maximum electron transport rate increased significantly with the progression of the season while the maximum light utilization efficiency for ETR (αETR) was constant. By contrast, the maximum gross oxygen photosynthetic capacity and the maximum light utilization efficiency for PB (αB) increased from December to May treatment but decreased from May to July treatment. Both techniques showed clear photoacclimation in microalgae with the progression of the season, as illustrated by changes in photosynthetic parameters. The relationship between the two techniques changed when high temperature, photoperiod and incident light were combined, possibly due to an overestimation of the PAR-averaged chlorophyll-specific absorption cross-section. Despite this change, our results illustrate the strong suitability of in vivo chlorophyll fluorimetry to estimate primary production in the field.

Dates et versions

hal-00481773 , version 1 (07-05-2010)

Identifiants

Citer

Sébastien Lefebvre, J.L. Mouget, Pascale Loret, Philippe Rosa, Gérard Tremblin. Comparison between fluorimetry and oxymetry techniques to measure photosynthesis in the diatom Skeletonema costatum cultivated under simulated seasonal conditions. Journal of Photochemistry and Photobiology B: Biology, 2007, 86 (2), pp.131-139. ⟨10.1016/j.jphotobiol.2006.08.012⟩. ⟨hal-00481773⟩
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