scholarly journals Action of Heavy Metals on Hill Activity and O2 Evolution in Anacystis nidulans

1987 ◽  
Vol 83 (1) ◽  
pp. 12-14 ◽  
Author(s):  
Devendra P. Singh ◽  
S. P. Singh
Keyword(s):  
Heavy Metals ◽  
Anacystis Nidulans ◽  
O2 Evolution ◽  
Hill Activity

Studies on the O2 Evolution under Flash Light Illumination in Preparations of Anacystis nidulans

1984 ◽  
Vol 39 (11-12) ◽  
pp. 1097-1103
Author(s):  
E. K. Pistorius ◽  
G. H. Schmid
Keyword(s):  
Reaction Center ◽  
Anacystis Nidulans ◽  
O2 Evolution ◽  
Dual Function ◽  
Light Illumination ◽  
Acid Oxidase ◽  
Typical Pattern ◽  
Amino Acid Oxidase ◽  
Light Flashes ◽  
Reduced State

Abstract The O2 yield under flash light illumination in preparations of Anacystis nidulans was examined in the presence of redox components such as ferricyanide and ferrocyanide. When ferricyanide (1 mᴍ) was added to the lyophilized, lysozyme treated and EDTA washed cells of A. nidulans the familiar Joliot-Kok oscillalion with maximum on the third flash and periodicity of four was observed (in the presence of added CaCl2 and MnCl2). However, when the ferricyanide con­centration was increased to about 8 mᴍ , a reduction of the O2 evolution under flash illumination was observed, and an O2 uptake could clearly be seen under the first and second flash. This O2 uptake was inhibited by DCMU and o-phenanthroline, but was not influenced by KCN or salicylhydroxamic acid. As ferrocyanide was progressively added to 1 mᴍ ferricyanide, the oscillations faded out and the steady-state O2 evolution decreased. Light would progressively increase the O2 evolution and reduce the damping of the oscillations. Two patterns of O2 evolution under short saturating light flashes were observed with these Anacystis preparations on first illumination in the presence of cations but in the absence of ferricyanide. One pattern corresponded to the typical pattern which has been repeatedly described in the literature, but the second pattern gave the indication of an initial “over-reduced” state of the photosystem II reaction center. With suitable procedures the two patterns were interchangeable. Moreover, the effect of ʟ-arginine on the flash pattern was examined. The results are discussed in connection with the possible dual function of the previously described flavin protein as an ʟ-amino acid oxidase and as a component of the O2 evolving reaction center (E. K. Pistorius and H. Voss, Eur. J. Biochemistry 126,203-209 (1982)).

Inactivation of Photosynthetic O2 Evolution in the Cyanobacterium Anacystis nidulans PCC 6301: Influence of Nitrogen Metabolites and Divalent Cation Concentration

1991 ◽  
Vol 46 (11-12) ◽  
pp. 1024-1032 ◽  
Author(s):  
Gudrun Wälzlein ◽  
Elfriede K. Pistorius
Keyword(s):  
Photosystem Ii ◽  
Nitrogen Source ◽  
Divalent Cation ◽  
Water Oxidation ◽  
Divalent Cations ◽  
Nitrogen Deficiency ◽  
Anacystis Nidulans ◽  
O2 Evolution ◽  
Cation Deficiency

Abstract An investigation about the in vivo inactivation of photosynthetic water oxidation has been carried out in the cyanobacterium Anacystis nidulans (Synechococcus PCC 6301). Photosystem II and photosystem I activity as well as the relative amount of the D1 and manganese stabilizing peptide of photosystem II were determined after growing the cells in nutrient media with variations in the nitrogen source and the concentration of the major divalent cations (Mg2+ and Ca2+). The results show a rapid inactivation of water oxidation in A. nidulans in response to nitrogen deficiency and in response to reduced Mg2+ and Ca2+ concentrations. The inactivation of water oxidation observed under divalent cation deficiency could be greatly accelerated when L-amino acids instead of ammonia or nitrate were used as nitrogen source. Under these conditions inactivation of water oxidation correlated with a rapid loss of D1 and with a slower loss of the manganese stabilizing peptide from photosystem II. A possible regulation of the photosystem II activity in A. nidulans by nitrogen metabolites is suggested.

Do Cyanobacteria Contain a Membrane Bound Cysteine Oxidase?

1985 ◽  
Vol 40 (3-4) ◽  
pp. 176-178 ◽  
Author(s):  
Eugene L. Barsky ◽  
Faina D. Kamilova ◽  
Vitaly D. Samuilov
Keyword(s):  
Heavy Metals ◽  
Ph Value ◽  
Anacystis Nidulans ◽  
Anabaena Variabilis ◽  
Cysteine Oxidation ◽  
Membrane Bound

The oxidation of cysteine with 02 is facilitated by isolated membranes of the cyanobacteria Anacystis nidulans and Anabaena variabilis, and further stimulated by Fe3+. This reaction accelerates with increasing the pH value and is suppressed by cyanide, benzylhydroxamate, hydroxylamine, but not azide. The agents mentioned inhibited the respiration of the membranes with ascorbate and N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD) effectively, but did not influence their nonenzymic oxidation. It is inferred that ascorbate in combination with TMPD is oxidized via membrane oxidases. Cysteine oxidation apparently proceeds non-enzymatically and is catalyzed by the cations of heavy metals.

Effects of combinations of heavy metals on hill activity of Azolla pinnata

1987 ◽  
Vol 35 (1-2) ◽  
pp. 141-145 ◽  
Author(s):  
Amar Sarkar ◽  
Sasadhar Jana
Keyword(s):  
Heavy Metals ◽  
Azolla Pinnata ◽  
Hill Activity

Sampling and analysis of the air-water interface with SEM and EDS of microlayers

1989 ◽  
Vol 47 ◽  
pp. 1004-1005
Author(s):  
Randall W. Smith ◽  
John Dash
Keyword(s):  
Heavy Metals ◽  
Surface Microlayer ◽  
Surface Films ◽  
Water Interface ◽  
Physical Processes ◽  
Infrared Spectroscopic Analysis ◽  
Eds Analysis ◽  
Air Water Interface ◽  
Significant Area ◽  
Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

Nicotianamine: mediator of transport of iron and heavy metals in the phloem?

1993 ◽  
Vol 88 (3) ◽  
pp. 522-529 ◽  
Author(s):  
Udo W. Stephan ◽  
Gunter Scholz
Keyword(s):  
Heavy Metals

Association between heavy metals and depression, anxiety, and panic: A cross-sectional study

2011 ◽  
Author(s):  
Parker Woody ◽  
Michael Zhang ◽  
Craig Pulsipher ◽  
Dawson Hedges ◽  
Bruce Brown
Keyword(s):  
Heavy Metals ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional
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