Photosynthetic acclimation of Chlorella saccharophila to heat stress

Abstract

Photosynthesis is one of the most important metabolic processes of algae; which is altered as a stress response. During mass cultivation of algae, temperature rise and high light are major factors that affect biomass productivity. High temperature affects photosystem II (PSII) complex irreversibly, damaging intermolecular interactions in it. However, the impact of high temperature on photosynthesis is highly variable among different algal species, depending on the prior acclimation to environmental conditions they were exposed to. The acclimation plays an important role in combating high temperature stress via regulation of photosynthetic responses. Chlorophyll a fluorescence is a highly sensitive, non-destructive and reliable tool for such measurements of photosynthetic parameters, which provides information about algal photosynthetic performance under given conditions. To understand the effect of heat stress on the responses of high light acclimated alga Chlorella saccharophila, chlorophyll a fluorescence transients were measured after heat exposure at 40 C. Our study demonstrates that rise in temperature for short duration; during open field cultivation reversibly affects the efficiency of PSII in light acclimated alga C. saccharophila. The effects of heat stress on chlorophyll a fluorescence in this alga, grown under high light (max-1600 μmol photons m −2 s −1 ) are presented here; they are used to infer changes in photosynthetic process during its exposure to heat, as well as their recovery after 72 h. We speculate that heat resistance may have been acquired due to prior exposures to high light.

Effects of suspended particles in the Jinjiang River Estuary on the physiological and biochemical characteristics of Microcystis flos-aquae

“…Photosynthesis is one of the most important metabolic activities of algae, and chlorophyll is its main pigment. Studies have shown that when algae are stressed by the outside world, the algae cell chlorophyll a will also be affected(Alahverdi &Savabieasfahani 2012, Metzler et al 2018, Patil et al 2017. In this study, with the increase of the concentration of particulate matter, the chlorophyll a content of Microcystis os-aquae gradually decreased, that is, the higher the concentration of particulate matter, the stronger the attenuation of light by suspended particles.…”

Effects of Water Particles in the Jinjiang River Estuary on the Physiological and Biochemical Characteristics of Microcystit Flos-Aquae

“…Photosynthesis is one of the most important metabolic activities of algae, and chlorophyll is its main pigment. Studies have shown that when algae are stressed by the outside world, the algae cell chlorophyll a will also be affected (Alahverdi &Savabieasfahani 2012, Metzler et al 2018, Patil et al 2017. In this study, with the increase of the concentration of particulate matter, the chlorophyll a content of Microcystis os-aquae gradually decreased, that is, the higher the concentration of particulate matter, the stronger the attenuation of light by suspended particles.…”

Response of Chlorophyll Fluorescence Characteristics and Dissolved Organic Matter for Marine Diatom Skeletonema dohrnii under Stress from Penicillin and Zn2+

“…It has been suggested that the stress-induced decrease in F v /F m is a short-term response of the photosystem under stress conditions, which may be a reconstructed equilibrium between light energy uptake and utilization by microalgae, minimizing damage to the algae [32]. Several studies have shown that the photosynthetic efficiency of algae decreases when subjected to environmental stress [33,34]. In this study, the F v /F m and F v /F o ratios of the algae decreased rapidly with increasing incubation time, indicating that the photosynthetic system of the microalgae was inhibited due to the addition of Zn 2+ .…”