Pools of cadmium in Chlamydomonas reinhardtii revealed by chemical imaging and XAS spectroscopy

Metallomics ◽  
2017 ◽  
Vol 9 (7) ◽  
pp. 910-923 ◽  
Author(s):  
F. Penen ◽  
M. P. Isaure ◽  
D. Dobritzsch ◽  
I. Bertalan ◽  
H. Castillo-Michel ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Chemical Imaging ◽  
Whole Cell ◽  
Polyphosphate Granules

The green micro-alga Chlamydomonas reinhardtii sequesters Cd as vacuolar Cd polyphosphate granules and Cd–thiol, diffused in the whole cell.

scholarly journals Whole cell solid-state NMR study of Chlamydomonas reinhardtii microalgae

2018 ◽  
Vol 70 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Alexandre A. Arnold ◽  
Jean-Philippe Bourgouin ◽  
Bertrand Genard ◽  
Dror E. Warschawski ◽  
Réjean Tremblay ◽  
...  
Keyword(s):  
Solid State ◽  
Chlamydomonas Reinhardtii ◽  
Solid State Nmr ◽  
Whole Cell ◽  
Nmr Study

scholarly journals Individual and Combined Effects of Extracellular Polymeric Substances and Whole Cell Components of Chlamydomonas reinhardtii on Silver Nanoparticle Synthesis and Stability

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 956 ◽  
Author(s):  
Ashiqur Rahman ◽  
Shishir Kumar ◽  
Adarsh Bafana ◽  
Si Dahoumane ◽  
Clayton Jeffryes
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Extracellular Polymeric Substances ◽  
Nanoparticle Synthesis ◽  
Cell Culture Supernatant ◽  
Bimodal Size Distribution ◽  
Whole Cell ◽  
Selected Area Electron Diffraction ◽  
Cell Components ◽  
Amine Groups ◽  
Silver Nanoparticle Synthesis

The fresh water microalga Chlamydomonas reinhardtii bioreduced Ag+ to silver nanoparticles (AgNPs) via three biosynthetic routes in a process that could be a more sustainable alternative to conventionally produced AgNPs. The AgNPs were synthesized in either the presence of whole cell cultures, an exopolysaccharide (EPS)-containing cell culture supernatant, or living cells that had been separated from the EPS-containing supernatant and then washed before being suspended again in fresh media. While AgNPs were produced by all three methods, the washed cultures had no supernatant-derived EPS and produced only unstable AgNPs, thus the supernatant-EPS was shown to be necessary to cap and stabilize the biogenic AgNPs. TEM images showed stable AgNPs were mostly spherical and showed a bimodal size distribution about the size ranges of 3.0 ± 1.3 nm and 19.2 ± 5.0 nm for whole cultures and 3.5 ± 0.6 nm and 17.4 ± 2.6 nm for EPS only. Moreover, selected area electron diffraction pattern of these AgNPs confirmed their polycrystalline nature. FTIR of the as-produced AgNPs identified polysaccharides, polyphenols and proteins were responsible for the observed differences in the AgNP stability, size and shape. Additionally, Raman spectroscopy indicated carboxylate and amine groups were bound to the AgNP surface.

Evolutionary diverse Chlamydomonas reinhardtii Old Yellow Enzymes reveal distinctive catalytic properties and potential for whole-cell biotransformations

2020 ◽  
Vol 50 ◽  
pp. 101970
Author(s):  
Stefanie Böhmer ◽  
Christina Marx ◽  
Álvaro Gómez-Baraibar ◽  
Marc M. Nowaczyk ◽  
Dirk Tischler ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Catalytic Properties ◽  
Whole Cell

HVEM Analysis of Microfilament Patterns in The Margins of Tissue Cells

1980 ◽  
Vol 38 ◽  
pp. 808-811
Author(s):  
Carol Allen
Keyword(s):  
Cell Movement ◽  
Cell Spreading ◽  
Living Cells ◽  
Tissue Cell ◽  
Large Sample Size ◽  
Cell Periphery ◽  
Whole Cell ◽  
Critical Point Drying ◽  
Lamellar Region ◽  
Tissue Cells

When provided with a suitable solid substrate, tissue cells undergo a rapid conversion from the spherical form expressed in suspension culture to a characteristic flattened morphology. As a result of this conversion, called cell spreading, the cell nucleus and organelles come to occupy a central region of “deep cytoplasm” which slopes steeply into a peripheral “lamellar” region less than 1 pm thick at its outer edge and generally free of cell organelles. Cell spreading is accomplished by a continuous outward repositioning of the lamellar margins. Cell translocation on the substrate results when the activity of the lamellae on one side of the cell become dominant. When this occurs, the cell is “polarized” and moves in the direction of the “leading lamellae”. Careful analysis of tissue cell locomotion by time-lapse microphotography (1) has shown that the deformational movements of the leading lamellae occur in a repeating cycle of advance and retreat in the direction of cell movement and that the rate of such deformations are positively correlated with the speed of cell movement. In the present study, the physical basis for these movements of the cell margin has been examined by comparative light microscopy of living cells with whole-mount electron microscopy of fixed cells. Ultrastructural observations were made on tissue cells grown on Formvar-coated grids, fixed with glutaraldehyde, further processed by critical-point drying, and then photographed in the High Voltage Electron Microscope. This processing and imaging system maintains the 3-dimensional organization of the whole cell, the relationship of the cell to the substrate, and affords a large sample size which facilitates quantitative analysis. Comparative analysis of film records of living cells with the whole-cell micrographs revealed that specific patterns of microfilament organization consistently accompany recognizable stages of lamellar formation and movement. The margins of spreading cells and the leading lamellae of locomoting cells showed a similar pattern of MF repositionings (Figs. 1-4). These results will be discussed in terms of a working model for the mechanics of lamellar motility which includes the following major features: (a) lamellar protrusion results when an intracellular force is exerted at a locally weak area of the cell periphery; (b) the association of cortical MFs with one another determines the local resistance to this force; (c) where MF-to-MF association is weak, the cell periphery expands and some cortical MFs are dragged passively forward; (d) contact of the expanded area with the substrate then triggers the lateral association and reorientation of these cortical MFs into MF bundles parallel to the direction of the expansion; and (e) an active interaction between these MF bundles associated with the cortex of the expanded lamellae and the cortical MFs which remained in the sub-lamellar region then pulls the latter MFs forward toward the expanded area. Thus, the advance of the cell periphery on the substrate occurs in two stages: a passive phase in which some cortical MFs are dragged outward by the force acting to expand the cell periphery, and an active phase in which additional cortical MFs are pulled forward by interaction with the first set. Subsequent interactions between peripheral microfilament bundles and filaments in the deeper cytoplasm could then transmit the advance gained by lamellar expansion to the bulk of the cytoplasm.

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