Rapid assessment of different oxygenic phototrophs and single-cell photosynthesis with multicolour variable chlorophyll fluorescence imaging

Trampe, Erik; Kolbowski, Jörg; Schreiber, Ulrich; Kühl, Michael

doi:10.1007/s00227-011-1663-1

Cited by 44 publications

(40 citation statements)

References 28 publications

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“…To confirm the results mentioned above, we assessed the ROS production and also measured the CAF which is an efficient method to evaluate the physiological state of the cells and works on detecting the auto‐fluorescence of the photosynthetic pigments present in microalgae and thus rate the damage occurring in the cells . Our study noted that the relative CAF levels showed a decrease in value, and an overall increase in the ROS production, both parameters changing with the increase of concentration for both CuCl 2 and K 2 Cr 2 O 7 (Figure ).…”

Section: Resultssupporting

confidence: 68%

Small heat shock protein genes of the green algae Closterium ehrenbergii: Cloning and differential expression under heat and heavy metal stresses

Abassi

Wang

Ponmani

et al. 2019

Environmental Toxicology

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The freshwater green algae Closterium ehrenbergii has been considered as a model for eco‐toxicological assessment in aquatic systems. Heat shock proteins (HSPs) are a class of highly conserved proteins produced in all living organisms, which participate in environmental stress responses. In the present study, we determined the cDNA sequences of small heat shock protein 10 (sHSP10) and sHSP17.1 from C. ehrenbergii, and examined the physiological changes and transcriptional responses of the genes after exposure to thermal shock and toxicants treatments. The open reading frame (ORF) of CeHSP10 was 300 bp long, encoding 99 amino acid (aa) residues (10.53 kDa) with a GroES chaperonin conserved site of 22 aa. The CeHSP17.1 had a 468 bp ORF, encoding 155 aa with a conserved C‐terminal α‐crystallin domain. For heat stress, cells presented pigment loss and possible chloroplast damage, with an up‐regulation in the expression of both sHSP10 and sHSP17.1 genes. As for the heavy metal stressors, an increase in the production of reactive oxygen species was registered in a dose dependent manner, with a significant up‐regulation of both sHSP10 and sHSP17.1 genes. These results suggest that sHSP genes in C. ehrenbergii may play a role in responses to stress environments, and they could be used as an early detection parameter as biomarker genes in molecular toxicity assessments.

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Section: Resultssupporting

confidence: 68%

Small heat shock protein genes of the green algae Closterium ehrenbergii: Cloning and differential expression under heat and heavy metal stresses

Abassi

Wang

Ponmani

et al. 2019

Environmental Toxicology

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“…Microalgae exhibit autofluorescence because of the presence of photosynthetic pigments (Trampe et al 2011). In the present study, CAF as MFI per cell (Appendix 1) noticeably decreased with increase in exposure time and NaOCl doses (Fig.…”

Section: Effects Of Naocl On Chl a Car And Caf Levelssupporting

confidence: 57%

Biocide sodium hypochlorite decreases pigment production and induces oxidative damage in the harmful dinoflagellate Cochlodinium polykrikoides

Ebenezer¹,

Ki²

2014

ALGAE

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The biocide sodium hypochlorite (NaOCl) is widely used for controlling algal growth, and this application can be extended to marine environments as well. This study evaluates the biocidal efficiency and cellular toxicity of NaOCl on the harmful dinoflagellate Cochlodinium polykrikoides, with emphasis on pigment production and antioxidant enzyme activity. The test organism showed dose-dependent decrease in growth rate on exposure to NaOCl, and the 72 h EC 50 was measured to be 0.584 mg L -1. NaOCl significantly decreased pigment levels and chlorophyll autofluorescence intensity, indicating possible detrimental effects on the photosystem of C. polykrikoides. Moreover, it significantly increased the activities of antioxidant enzymes, suggesting the production of reactive oxygen species in the cells. These data indicate that NaOCl exerted deleterious effects on the photosynthetic machinery and induced oxidative damage in the dinoflagellate and this biocide could be effectively used for the control of algal blooms.

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“…The blue LEDs (470 nm) provided both weak pulses of measuring light as well as defined levels of actinic light measured as downwelling photon irradiance, E d , in the focus plane of the system with a calibrated irradiance meter (LI-250 and LI-192, LiCor, USA). A detailed description of variable chlorophyll fluorescence imaging systems is given elsewhere (Grunwald and Kühl, 2004; Ralph et al, 2005; Kühl and Polerecky, 2008; Trampe et al, 2011). The system enabled quantification of a proxy for PAR absorptivity, A, by measuring the reflected red light ( R , 650 nm) and NIR ( R NIR , 780 nm) from the specimen/sample and calculating the ratio A = 1 − ( R / R NIR ).…”

Section: Methodsmentioning

confidence: 99%

Microenvironmental Ecology of the Chlorophyll b-Containing Symbiotic Cyanobacterium Prochloron in the Didemnid Ascidian Lissoclinum patella

et al. 2012

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The discovery of the cyanobacterium Prochloron was the first finding of a bacterial oxyphototroph with chlorophyll (Chl) b, in addition to Chl a. It was first described as Prochloron didemni but a number of clades have since been described. Prochloron is a conspicuously large (7–25 μm) unicellular cyanobacterium living in a symbiotic relationship, primarily with (sub-) tropical didemnid ascidians; it has resisted numerous cultivation attempts and appears truly obligatory symbiotic. Recently, a Prochloron draft genome was published, revealing no lack of metabolic genes that could explain the apparent inability to reproduce and sustain photosynthesis in a free-living stage. Possibly, the unsuccessful cultivation is partly due to a lack of knowledge about the microenvironmental conditions and ecophysiology of Prochloron in its natural habitat. We used microsensors, variable chlorophyll fluorescence imaging and imaging of O2 and pH to obtain a detailed insight to the microenvironmental ecology and photobiology of Prochloron in hospite in the didemnid ascidian Lissoclinum patella. The microenvironment within ascidians is characterized by steep gradients of light and chemical parameters that change rapidly with varying irradiances. The interior zone of the ascidians harboring Prochloron thus became anoxic and acidic within a few minutes of darkness, while the same zone exhibited O2 super-saturation and strongly alkaline pH after a few minutes of illumination. Photosynthesis showed lack of photoinhibition even at high irradiances equivalent to full sunlight, and photosynthesis recovered rapidly after periods of anoxia. We discuss these new insights on the ecological niche of Prochloron and possible interactions with its host and other microbes in light of its recently published genome and a recent study of the overall microbial diversity and metagenome of L. patella.

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Rapid assessment of different oxygenic phototrophs and single-cell photosynthesis with multicolour variable chlorophyll fluorescence imaging

Cited by 44 publications

References 28 publications

Small heat shock protein genes of the green algae Closterium ehrenbergii: Cloning and differential expression under heat and heavy metal stresses

Small heat shock protein genes of the green algae Closterium ehrenbergii: Cloning and differential expression under heat and heavy metal stresses

Biocide sodium hypochlorite decreases pigment production and induces oxidative damage in the harmful dinoflagellate Cochlodinium polykrikoides

Microenvironmental Ecology of the Chlorophyll b-Containing Symbiotic Cyanobacterium Prochloron in the Didemnid Ascidian Lissoclinum patella

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