Antioxidative Responses of Two Marine Microalgae During Acclimation to Static and Fluctuating Natural UV Radiation

Janknegt, Paul J.; Graaff, C. Marco de; Poll, Willem H. van de; Visser, Ronald J. W.; Helbling, E. Walter; Buma, Anita G. J.

doi:10.1111/j.1751-1097.2009.00603.x

Cited by 19 publications

(11 citation statements)

References 62 publications

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“…To explain the behavior of the enzyme for these cells, we can hypothesize several points. (i) SODs are metalloproteins that catalyze the dismutation of O 2 − to H 2 O 2 and O 2 [53,61,62]. Depending on the transition metal found in its active site, SODs can be categorized into three types: Cu/Zn-SOD, Mn-SOD, and Fe-SOD.…”

Section: Discussionmentioning

confidence: 99%

An Analytical–Experimental Approach to Quantifying the Effects of Static Magnetic Fields for Cell Culture Applications

et al. 2020

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This work aimed to study the effects of static magnetic fields (SMFs) on cell cultures. A glass flask was filled with a liquid medium, which was surrounded by permanent magnets. Air was introduced through a tube to inject bubbles. Two magnet configurations, north and south, were used as perturbation. Scenedesmus obliquus and Nannochloropsis gaditana, growing in Medium 1 and 2, were subjected to the bubbly flow and SMFs. Differences between media were mainly due to conductivity (0.09 S/m for Medium 1 and 4.3 S/m for Medium 2). Joule dissipation ( P ) increased with the magnetic flux density ( B 0 ), being 4 orders of magnitude higher in Medium 2 than in 1. Conversely, the time constant ( τ P ) depended on B 0 , being nearly constant for Medium 1 and decreasing at 449 s/T for Medium 2. Dissipation occurred with the same τ P (235 s) in Medium 1 and 2 at B 0 = 0.5 T. In Species 1, the SMF effect was inhibitory. For Species 2, a higher enzymatic activity was observed. For superoxide dismutase, the relative difference was 78% with the north and 115% with the south configuration compared to the control values. For the catalase, differences of 29% with the north and 23% with the south configuration compared to control condition were obtained.

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Section: Discussionmentioning

confidence: 99%

An Analytical–Experimental Approach to Quantifying the Effects of Static Magnetic Fields for Cell Culture Applications

et al. 2020

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“…Simultaneously, microalgae are exposed to Ultra Violet Radiation (UVR, <400 nm) which has the potential to damage important biochemical molecules (Larson and Berenbaum, 1988). Excess radiance levels of PAR and UVR may result in the formation of Reactive Oxygen Species (ROS) which may lead to a decreased photosynthetic efficiency or even viability loss (Janknegt et al, 2009a). At the same time, light may also affect compound toxicity in several ways.…”

Section: Introductionmentioning

confidence: 99%

Seasonal variability in irradiance affects herbicide toxicity to the marine flagellate Dunaliella tertiolecta

Sjollema¹,

Vavourakis²,

Geest³

et al. 2014

Front. Mar. Sci.

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Photosynthetically Active Radiation (PAR) and Ultraviolet Radiation (UVR) of the solar spectrum affect microalgae directly and modify the toxicity of phytotoxic compounds present in water. As a consequence seasonal variable PAR and UVR levels are likely to modulate the toxic pressure of contaminants in the field. Therefore, the present study aimed to determine the toxicity of two model contaminants, the herbicides diuron and Irgarol ® 1051, under simulated irradiance conditions mimicking different seasons. Irradiance conditions of spring and autumn were simulated with a set of Light Emitting Diodes (LEDs). Toxicity of both herbicides was measured individually and in a mixture by determining the inhibition of photosystem II efficiency ( PSII) of the marine flagellate Dunaliella teriolecta using Pulse Amplitude Modulation (PAM) fluorometry. Toxicity of the single herbicides was higher under simulated spring irradiance than under autumn irradiance and this effect was also observed for a mixture of the herbicides. This irradiance dependent toxicity indicates that herbicide toxicity in the field is seasonally variable. Consequently toxicity tests under standard light conditions may overestimate or underestimate the toxic effect of phytotoxic compounds

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“…(1) avoid excess light energy absorption by decreasing cell pigment content (MacIntyre et al 2002), (2) dissipate excess excitation energy as heat in a process called Non-Photochemical Quenching of chlorophyll a (Chl a) fluorescence (NPQ) (Lavaud and Goss 2014;Goss and Lepetit 2015), and/or by engaging alternative electron cycling pathways (Wagner et al 2016), (3) scavenge reactive oxygen species (ROS) (Janknegt et al 2008(Janknegt et al , 2009aWaring et al 2010), (4) repair damaged PSII cores, mainly by replacing the D1 protein of the PSII reaction center (Wu et al 2011;Lavaud et al 2016), (5) behavioral down regulation through vertical cell movement (microcycling and bulk migration) (Kromkamp et al 1998;Serôdio 2004). Of the above mechanisms, especially NPQ is able to track fast light fluctuations experienced in the natural habitat (Brunet and Lavaud 2010;Lavaud and Goss 2014).…”

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confidence: 99%

Contrasting NPQ dynamics and xanthophyll cycling in a motile and a non‐motile intertidal benthic diatom

Blommaert

Huysman

Vyverman

et al. 2017

Limnology & Oceanography

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Diatoms living in intertidal sediments have to be able to rapidly adjust photosynthesis in response to often pronounced changes in light intensity during tidal cycles and changes in weather conditions. Strategies to deal with oversaturating light conditions, however, differ between growth forms. Motile epipelic diatoms can migrate to more optimal light conditions. In contrast, non-motile epipsammic diatoms appear to mainly rely on higher Non-Photochemical Quenching (NPQ) of chlorophyll a fluorescence to dissipate excess light energy, and this has been related to a larger pool of xanthophyll cycle (XC) pigments. We studied the effect of 1 h high Photosynthetically Available Radiation (PAR) (2000 lmol photons m 22 s 21 ) on the kinetics of the xanthophyll cycle and NPQ in both a motile diatom (Seminavis robusta) and a non-motile diatom (Opephora guenter-grassii) in an experimental set-up which did not allow for vertical migration. O. guenter-grassii could rapidly switch NPQ on and off by relying on fast XC kinetics. This species also demonstrated high de novo synthesis of xanthophylls within a relatively short period of time (1 h), including significant amounts of zeaxanthin, a feature not observed before in other diatoms. In contrast, S. robusta showed slower NPQ and associated XC kinetics, partly relying on NPQ conferred by de novo synthetized diatoxanthin molecules and synthesis of Light-Harvesting Complex X (LHCX) isoforms. Part of this observed NPQ increase, however, is sustained quenching (NPQs). Our data illustrate the high and diverse adaptive capacity of microalgal growth forms to maximize photosynthesis in dynamic light environments.

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Antioxidative Responses of Two Marine Microalgae During Acclimation to Static and Fluctuating Natural UV Radiation

Cited by 19 publications

References 62 publications

An Analytical–Experimental Approach to Quantifying the Effects of Static Magnetic Fields for Cell Culture Applications

An Analytical–Experimental Approach to Quantifying the Effects of Static Magnetic Fields for Cell Culture Applications

Seasonal variability in irradiance affects herbicide toxicity to the marine flagellate Dunaliella tertiolecta

Contrasting NPQ dynamics and xanthophyll cycling in a motile and a non‐motile intertidal benthic diatom

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