Adsorption of chlorophyll-a from acetone solution on natural and activated bentonite

1994 ◽  
Vol 61 (2) ◽  
pp. 175-178 ◽  
Author(s):  
E. González Pradas ◽  
M. Villafranca Sánchez ◽  
M. Socías Viciana ◽  
A. Gallego Campo
Keyword(s):  
Chlorophyll A ◽  
Acetone Solution ◽  
Activated Bentonite

scholarly journals Some characteristics of purpurin-18synthesised from chlorophyll a of Spirulina

2021 ◽  
Vol 63 (11) ◽  
pp. 40-43
Author(s):  
Minh Hieu Nguyen ◽  
◽  
Binh Duong Le ◽  
Anh Tuan Mai ◽  
Thi Binh Nguyen ◽  
...  
Keyword(s):  
Fluorescence Spectroscopy ◽  
Chlorophyll A ◽  
Fluorescence Lifetime ◽  
Acetone Solution ◽  
Research Groups ◽  
Good Dispersion

Research and synthesis of photosensitive purpurin 18 (Pp-18) from nature is one of the topics that many research groups are interested in and developing. In this study, the authors defined some characteristics of Pp-18 synthesised from chlorophyll a - a substance isolated from Spirulina. The results showed that Pp-18 had good dispersion in acetone at 478.5 nm (R2=0.98285) and reached 98%. Fluorescence spectroscopy of Pp-18 in acetone was measured at a concentration of 70 ppm, wavelengths 365.39, 417.62, and 557.96 nm. The fluorescence lifetime of Pp-18 in acetone solution was 2.85 ns.

scholarly journals Efek Beta Karoten dan Agregasi Klorofil Pada Fotostabilitas Klorofil a dalam Pelarut Aseton

2012 ◽  
Vol 11 (2) ◽  
pp. 115
Author(s):  
Junet. F. da Costa ◽  
Ferry F Karwur ◽  
Leenawaty Limantara
Keyword(s):  
Chlorophyll A ◽  
Red Light ◽  
Photosynthetic Pigment ◽  
Beta Carotene ◽  
Acetone Solution ◽  
Aggregate Form ◽  
Color Additive ◽  
The Stability

Chlorophyll as photosynthetic pigment has many benefits to human such as antioxidant, antibacterial, color additive,immunity, and photosensitizer. Concerning to these applications, chlorophyll a will react with oxygen and light andreduce its effectiveness. It is then important to understand the stability of chlorophyll a on oxygen and light.Stability of chlorophyll a in the presence of beta-carotene (1:1) in acetone was studied for various waterconcentrations. Each solution was exposed to red light (ë e” 630 nm) for 0.5; 1.0; 2.5; 5.0; 10; 20; 30; 40; 50; and 60minutes and their spectrum were analysed. When water was added (8.33; 16.67; 25; 33.33; 41.67; 50; 58.33; 66.67;75; and 83.33 percent) to the acetone solution of chlorophyll a, the chlorophylls aggregate, and in the presence ofbeta-carotene, the chlorophyll more stable. The water shifts the chlorophyll a spectrum toward red duringillumination with or without the presence of carotene. The formation of oligomeric chlorophyll a aggregate occurswithin 10-20 minutes after the water was applied. This strategy of aggregating the chlorophylls to dissipateexcess energy captured from light does not support the photostability of chlorophyll as much as beta-carotene.Surprisingly, when beta carotene was mixed with 66.7% and 75.0% of water, the chlorophyll a degraded 5.56% and9.71% respectively. In conclusion, the aggregate form of chlorophyll a and the presence of beta-carotene increasephotostability of chlorophyll a in acetone solution.

High-Resolution electron crystallography of the light-harvesting chlorophyll-a/b protein complex from chloroplast membranes

1990 ◽  
Vol 48 (1) ◽  
pp. 610-610
Author(s):  
Werner Kühlbrandt ◽  
Da Neng Wang ◽  
K.H. Downing
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Chlorophyll A ◽  
Protein Complex ◽  
Structural Integrity ◽  
Light Harvesting ◽  
Lhc Ii ◽  
Diffraction Patterns ◽  
Difference Fourier ◽  
2D Crystals

The light-harvesting chlorophyll-a/b protein complex (LHC-II) is the most abundant membrane protein in the chloroplasts of green plants where it functions as a molecular antenna of solar energy for photosynthesis. We have grown two-dimensional (2d) crystals of the purified, detergent-solubilized LHC-II . The crystals which measured 5 to 10 μm in diameter were stabilized for electron microscopy by washing with a 0.5% solution of tannin. Electron diffraction patterns of untilted 2d crystals cooled to 130 K showed sharp spots to 3.1 Å resolution. Spot-scan images of 2d crystals were recorded at 160 K with the Berkeley microscope . Images of untilted crystals were processed, using the unbending procedure by Henderson et al . A projection map of the complex at 3.7Å resolution was generated from electron diffraction amplitudes and high-resolution phases obtained by image processing .A difference Fourier analysis with the same image phases and electron diffraction amplitudes recorded of frozen, hydrated specimens showed no significant differences in the 3.7Å projection map. Our tannin treatment therefore does not affect the structural integrity of the complex.

Identification of a single-copy gene encoding a Type I chlorophyll a/b-binding polypeptide of photosystem I in Arabidopsis thaliana

1992 ◽  
Vol 84 (4) ◽  
pp. 561-567 ◽  
Author(s):  
Poul E. Jensen ◽  
Michael Kristensen ◽  
Tine Hoff ◽  
Jan Lehmbeck ◽  
Bjarne M. Stummann ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Chlorophyll A ◽  
Photosystem I ◽  
Single Copy ◽  
Type I ◽  
Single Copy Gene ◽  
Gene Encoding ◽  
Copy Gene

Modeling of photosynthesis light curves by linear splines

2019 ◽  
pp. 20-29
Author(s):  
Alexander S. Lelekov ◽  
Rudolf P. Trenkenshu
Keyword(s):  
Experimental Data ◽  
Chlorophyll A ◽  
Skeletonema Costatum ◽  
Light Flux ◽  
Photosynthesis Rate ◽  
Light Curves ◽  
External Irradiation ◽  
Exchange Reactions ◽  
Cell Adaptation ◽  
Linear Splines

The paper presents an example of the linear splines use to describe the photosynthesis light curves for microalgae culture. The main mathematical models of the relationship between photosynthesis rate and light are listed. Based on the previously formulated basic principles of modeling microalgae photobiosynthesis, a mathematical model is proposed that describes the dependence of the assimilation number of chlorophyll a on the value of the light flux by linear splines. The advantage of the proposed approach is a clear definition of the point of change of the limiting factor. It is shown that light-limited photosynthesis rate is determined not only by external irradiation, but also by the concentration of chlorophyll a. The light-saturated rate depends on the amount of a key enzyme complex, which limits the rate of energy exchange reactions in the cell. Verification of the proposed model on the example of the diatom microalgae Skeletonema costatum was carried out. It is shown that the higher the degree of cell adaptation to high irradiation, the better the photosynthesis curve is described by linear splines. If S. costatum cells are adapted to low irradiation, deviations of experimental data from the idealized broken line are observed, which are caused by changes in the pigment composition. When the experimental data are normalized, the cell adaptation factor is reduced, all points are described by a single broken line, which indicates the universality of the proposed approach.

Estimation of chlorophyll content by absorption spectra of native Spirulina platensis cells

2020 ◽  
pp. 25-33
Author(s):  
Leonid E. Paramonov
Keyword(s):  
Chlorophyll Content ◽  
Chlorophyll A ◽  
Absorption Spectra ◽  
Spirulina Platensis ◽  
Intracellular Concentration ◽  
Absorption Coefficients

A method for retrieving the absorption coefficients of Spirulina platensis pigments using absorption spectra of native cells and excluding the use of extracts is considered. Estimates of the intracellular concentration of chlorophyll a, С-phycoerythrin, С- phycocyanin and allophycocyanin in native cells are discussed.

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