Influence of Algae Age and Population on the Response to TiO2 Nanoparticles

Abstract

This work shows the influence of algae age (at the time of the exposure) and the initial algae population on the response of green algae Raphidocelis subcapitata to titanium dioxide nanoparticles (TiO2 NPs). The different algae age was obtained by changes in flow rate of continually stirred tank reactors prior to NP exposure. Increased algae age led to a decreased growth, variations in chlorophyll content, and an increased lipid peroxidation. Increased initial algae population (0.3−4.2 × 106 cells/mL) at a constant NP concentration (100 mg/L) caused a decline in the growth of algae. With increased initial algae population, the lipid peroxidation and chlorophyll both initially decreased and then increased. Lipid peroxidation had 4× the amount of the control at high and low initial population but, at mid-ranged initial population, had approximately half the control value. Chlorophyll a results also showed a similar trend. These results indicate that the physiological state of the algae is important for the toxicological effect of TiO2 NPs. The condition of algae and exposure regime must be considered in detail when assessing the toxicological response of NPs to algae.

Continuous measurements of volatile gases as detection of algae crop health

“…Based on the transient and disproportionate biomass-dependent nature of this response, we have hypothesized that this feature is unlikely to be caused directly by degradation of biomass or increased encounter rates but instead may represent a defense response that is nonlinearly amplified by denser cell populations. The possibility that algae respond to stressful stimuli in a population-dependent manner, as has been observed in the literature to abiotic stress ( 45 ), indicates that gas analysis as a diagnostic method will likely require multiple data types to contextualize the overall SoH of the algal crop. Second, we observed that overall signal changes occur earlier when infection occurs at a higher initial biomass density ( Fig.…”

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.…”