Influence of Molecular Oxygen on the Chlorophyll Fluorescence Decay of Green Algae

1999 ◽  
Vol 54 (5-6) ◽  
pp. 348-352 ◽  
Author(s):  
Silke Oellerich ◽  
Daniel Berg ◽  
Karlheinz Maier ◽  
Frank Terjung
Keyword(s):  
Chlorophyll Fluorescence ◽  
Molecular Oxygen ◽  
Chlorophyll A ◽  
Green Algae ◽  
Chlorella Vulgaris ◽  
Fluorescence Decay ◽  
Singlet Excited State ◽  
Chlorophyll Fluorescence Quenching ◽  
Photosynthetic Organisms ◽  
Quenching By Oxygen

Abstract Chlorella vulgaris, Chlorophyll Fluorescence Quenching, Green Algae, Molecular Oxygen Molecular oxygen can act as a collisional quencher of the singlet excited state of chlorophyll a. This effect is well described for chlorophyll a in various solvents but not for chlorophyll a in the antenna complexes of photosynthetic organisms. We studied the chlorophyll fluorescence decay of Chlorella vulgaris cells under different oxygen concentrations but did not find any evidence for quenching by oxygen.

Hydroxylation of the C132 and C18 carbons of chlorophylls by heme and molecular oxygen

2015 ◽  
Vol 19 (09) ◽  
pp. 1007-1013 ◽  
Author(s):  
Patrick C. Loughlin ◽  
Robert D. Willows ◽  
Min Chen
Keyword(s):  
Aqueous Solution ◽  
Molecular Oxygen ◽  
Chlorophyll A ◽  
Oxidation Products ◽  
Chlorophyll B ◽  
Need For Care ◽  
Photosynthetic Organisms ◽  
Major Oxidation ◽  
Oxygen Atoms

Following extraction from photosynthetic organisms, chlorophylls are prone to reactions including demetalation, dephytylation and specific oxidations of the exocyclic ring E, termed allomerizations. Allomerization of chlorophylls has been well-characterized in methanol and to a lesser extent in aqueous solution. Here we detail novel allomerization-like reactions of chlorophyll a and chlorophyll b. In the presence of heme, detergent-solubilized chlorophyll a is hydroxylated at its C 132 position in ring E and, surprisingly, the C 18 position in ring D. Two major oxidation products are synthesized — a C 132- OH and a C 132- OH , C 18- OH derivative of chlorophyll a. We track the origin of the oxygen atoms added in these hydroxylated chlorophylls using 18 O 2 labeling and demonstrate that the additional oxygen atoms are derived from molecular oxygen. A similar heme-catalyzed reaction is also observed using chlorophyll b as a substrate. These results highlight the need for care when dealing with extracted chlorophylls and demonstrate an unusual hydroxylation of the C 18 position of chlorophylls in the presence of heme.

scholarly journals The Adaptive Ability of Cornus Stolonifera Michx. ´Kelseyi´ in Changing Environment

2014 ◽  
Vol 17 (1) ◽  
pp. 20-23
Author(s):  
Daniela Bartošová Krajčovičová ◽  
Viera Šajbidorová
Keyword(s):  
Chlorophyll Fluorescence ◽  
Chlorophyll A ◽  
Effective Quantum Yield ◽  
Water Efficiency ◽  
Chlorophyll Fluorescence Parameters ◽  
Chlorophyll Fluorescence Quenching ◽  
Cornus Stolonifera ◽  
Substrate Saturation ◽  
Fluorescence Of Chlorophyll A ◽  
Adaptive Ability

Abstract Water represents one of the limiting environmental factors having impact on all the processes in plants. Water stress is considered as the most significant cause of photosynthesis defects. Measuring fluorescence of chlorophyll a is one of the methods revealing defects in the photosynthetic aparatus. The examination has been carried out on the plants Cornus stolonifera Michx. ´KELSEYI´ cultivated in two different irrigation regimes (a regime with 40% substrate saturation and a controlling regime with 60% substrate saturation). We have used a fluorometer HANSATECH FMS 1 to measure modulated fluorescence of chlorophyll a. A three-week period of measurement was set between June and August during two years of experiments (2011 and 2012). The selected chlorophyll fluorescence parameters Fv /Fm - maximum quantum efficiency of PSII; ΦPSII - effective quantum yield of PSII; Rfd - chlorophyll fluorescence decrease ratio and NPQ - non-photochemical chlorophyll fluorescence quenching, proved to be insensitive to given water deficit. Cornus stolonifera Michx. ´KELSEY´ appears to be a woody plant capable of water efficiency.

In Vivo Fluorescence of Chlorophyll A: Estimation of Phytoplankton Biomass and Activity in Římov Reservoir (Czech Republic)

1993 ◽  
Vol 28 (6) ◽  
pp. 29-33 ◽  
Author(s):  
V. Vyhnálek ◽  
Z. Fišar ◽  
A. Fišarová ◽  
J. Komárková
Keyword(s):  
Czech Republic ◽  
Chlorophyll Fluorescence ◽  
Primary Production ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
In Vivo Fluorescence ◽  
Fluorescence Of Chlorophyll A ◽  
Římov Reservoir ◽  
Natural Phytoplankton

The in vivo fluorescence of chlorophyll a was measured in samples of natural phytoplankton taken from the Římov Reservoir (Czech Republic) during the years 1987 and 1988. The fluorescence intensities of samples either with or without addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron, DCMU) were found reliable for calculating the concentration of chlorophyll a during periods when cyanobacteria were not abundant. The correction for background non-chlorophyll fluorescence appeared to be essential. No distinct correlation between a DCMU-induced increase of the fluorescence and primary production of phytoplankton was found.

scholarly journals Rapid Quantification of Microalgae Growth with Hyperspectral Camera and Vegetation Indices

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 341
Author(s):  
Pauliina Salmi ◽  
Matti A. Eskelinen ◽  
Matti T. Leppänen ◽  
Ilkka Pölönen
Keyword(s):  
Chlorophyll Fluorescence ◽  
Chlorophyll A ◽  
Near Infrared ◽  
Vegetation Indices ◽  
Hyperspectral Data ◽  
Strong Correlations ◽  
Algae Biomass ◽  
Chlorophyll A Concentration ◽  
Cost Efficient ◽  
Hyperspectral Camera

Spectral cameras are traditionally used in remote sensing of microalgae, but increasingly also in laboratory-scale applications, to study and monitor algae biomass in cultures. Practical and cost-efficient protocols for collecting and analyzing hyperspectral data are currently needed. The purpose of this study was to test a commercial, easy-to-use hyperspectral camera to monitor the growth of different algae strains in liquid samples. Indices calculated from wavebands from transmission imaging were compared against algae abundance and wet biomass obtained from an electronic cell counter, chlorophyll a concentration, and chlorophyll fluorescence. A ratio of selected wavebands containing near-infrared and red turned out to be a powerful index because it was simple to calculate and interpret, yet it yielded strong correlations to abundances strain-specifically (0.85 < r < 0.96, p < 0.001). When all the indices formulated as A/B, A/(A + B) or (A − B)/(A + B), where A and B were wavebands of the spectral camera, were scrutinized, good correlations were found amongst them for biomass of each strain (0.66 < r < 0.98, p < 0.001). Comparison of near-infrared/red index to chlorophyll a concentration demonstrated that small-celled strains had higher chlorophyll absorbance compared to strains with larger cells. The comparison of spectral imaging to chlorophyll fluorescence was done for one strain of green algae and yielded strong correlations (near-infrared/red, r = 0.97, p < 0.001). Consequently, we described a simple imaging setup and information extraction based on vegetation indices that could be used to monitor algae cultures.

scholarly journals Macroalgae

Encyclopedia ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 177-188
Author(s):  
Leonel Pereira
Keyword(s):  
Carbon Dioxide ◽  
Chlorophyll A ◽  
Red Algae ◽  
Great Variability ◽  
Marine Macroalgae ◽  
Brown Macroalgae ◽  
Green Macroalgae ◽  
Red Macroalgae ◽  
Photosynthetic Organisms ◽  
Green Pigments

What are algae? Algae are organisms that perform photosynthesis; that is, they absorb carbon dioxide and release oxygen (therefore they have chlorophyll, a group of green pigments used by photosynthetic organisms that convert sunlight into energy via photosynthesis) and live in water or in humid places. Algae have great variability and are divided into microalgae, small in size and only visible through a microscope, and macroalgae, which are larger in size, up to more than 50 m (the maximum recorded was 65 m), and have a greater diversity in the oceans. Thus, the term “algae” is commonly used to refer to “marine macroalgae or seaweeds”. It is estimated that 1800 different brown macroalgae, 6200 red macroalgae, and 1800 green macroalgae are found in the marine environment. Although the red algae are more diverse, the brown ones are the largest.

Sign in / Sign up

Export Citation Format

Share Document