Effect of temperature on microcystin-LR removal and lysis activity on Microcystis aeruginosa (cyanobacteria) by an indigenous bacterium belonging to the genus Achromobacter

2020 ◽  
Vol 27 (35) ◽  
pp. 44427-44439
Author(s):  
Melina Crettaz-Minaglia ◽  
Maximiliano Fallico ◽  
Oswaldo Aranda ◽  
Ivan Juarez ◽  
Magdalena Pezzoni ◽  
...  
Keyword(s):  
Microcystis Aeruginosa ◽  
Effect Of Temperature ◽  
Indigenous Bacterium ◽  
Lysis Activity

scholarly journals Episodic Decrease in Temperature Increases mcy Gene Transcription and Cellular Microcystin in Continuous Cultures of Microcystis aeruginosa PCC 7806

2020 ◽  
Vol 11 ◽  
Author(s):  
Robbie M. Martin ◽  
Mohammad Moniruzzaman ◽  
Gwendolyn F. Stark ◽  
Eric R. Gann ◽  
Dominique S. Derminio ◽  
...  
Keyword(s):  
Rna Sequencing ◽  
Microcystis Aeruginosa ◽  
Temporal Dynamics ◽  
Nitrogen Concentration ◽  
Time Lag ◽  
Cyanobacterial Blooms ◽  
Health Concern ◽  
Effect Of Temperature ◽  
Continuous Cultures ◽  
Harmful Cyanobacterial Blooms

Microcystins produced during harmful cyanobacterial blooms are a public health concern. Although patterns are emerging, the environmental cues that stimulate production of microcystin remain confusing, hindering our ability to predict fluctuations in bloom toxicity. In earlier work, growth at cool temperatures relative to optimum (18°C vs. 26°C) was confirmed to increase microcystin quota in batch cultures of Microcystis aeruginosa NIES-843. Here, we tested this response in M. aeruginosa PCC 7806 using continuous cultures to examine temporal dynamics and using RNA-sequencing to investigate the physiological nature of the response. A temperature reduction from 26 to 19°C increased microcystin quota ∼2-fold, from an average of ∼464 ag μm–3 cell volume to ∼891 ag μm–3 over a 7–9 d period. Reverting the temperature to 26°C returned the cellular microcystin quota to ∼489 ag μm–3. Long periods (31–42 d) at 19°C did not increase or decrease microcystin quota beyond that observed at 7–9 d. Nitrogen concentration had little effect on the overall response. RNA sequencing indicated that the decrease in temperature to 19°C induced a classic cold-stress response in M. aeruginosa PCC 7806, but this operated on a different timescale than the increased microcystin production. Microcystin quota showed a strong 48- to 72-h time-lag correlation to mcy gene expression, but no correlation to concurrent mcy expression. This work confirms an effect of temperature on microcystin quota and extends our understanding of the physiological nature of the response.

Nucleation of Disorder in Fe3Al Alloys

1967 ◽  
Vol 25 ◽  
pp. 312-313
Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Antiphase Domain ◽  
Effect Of Temperature ◽  
Domain Structures ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Higher Temperature ◽  
The One

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.

The effect of temperature on high-resolution TEM image contrast

1995 ◽  
Vol 53 ◽  
pp. 640-641
Author(s):  
T. Geipel ◽  
W. Mader ◽  
P. Pirouz
Keyword(s):  
Form Factor ◽  
Inelastic Scattering ◽  
Accurate Method ◽  
Waller Factor ◽  
Effect Of Temperature ◽  
Specimen Thickness ◽  
Influence Of Temperature ◽  
Debye Waller Factor ◽  
Influence Of Temperature On ◽  
Atomic Form Factor

Temperature affects both elastic and inelastic scattering of electrons in a crystal. The Debye-Waller factor, B, describes the influence of temperature on the elastic scattering of electrons, whereas the imaginary part of the (complex) atomic form factor, fc = fr + ifi, describes the influence of temperature on the inelastic scattering of electrons (i.e. absorption). In HRTEM simulations, two possible ways to include absorption are: (i) an approximate method in which absorption is described by a phenomenological constant, μ, i.e. fi; - μfr, with the real part of the atomic form factor, fr, obtained from Hartree-Fock calculations, (ii) a more accurate method in which the absorptive components, fi of the atomic form factor are explicitly calculated. In this contribution, the inclusion of both the Debye-Waller factor and absorption on HRTEM images of a (Oll)-oriented GaAs crystal are presented (using the EMS software.Fig. 1 shows the the amplitudes and phases of the dominant 111 beams as a function of the specimen thickness, t, for the cases when μ = 0 (i.e. no absorption, solid line) and μ = 0.1 (with absorption, dashed line).

The development of dormancy in bulblets of Lilium speciosum generated in vitro. II. The effect of temperature

1990 ◽  
Vol 80 (3) ◽  
pp. 431-436 ◽  
Author(s):  
Isabelle Delvallee ◽  
Annie Paffen ◽  
Geert-Jan De Klerk
Keyword(s):  
Effect Of Temperature ◽  
Lilium Speciosum

Effect of Temperature on ADP-Induced Platelet Aggregation

1973 ◽  
Vol 29 (01) ◽  
pp. 183-189
Author(s):  
C. A Praga ◽  
E. M Pogliani
Keyword(s):  
Platelet Aggregation ◽  
Incubation Period ◽  
Room Temperature ◽  
Important Variable ◽  
Practical Significance ◽  
Effect Of Temperature ◽  
Induce Platelet Aggregation ◽  
Cuvette Holder ◽  
Exact Temperature

SummaryTemperature represents a very important variable in ADP-induced platelet aggregation.When low doses of ADP ( < 1 (μM) are used to induce platelet aggregation, the length of the incubation period of PRP in the cuvette holder of the aggregometer, thermostatted at 37° C, is very critical. Samples of the same PRP previously kept at room temperature, were incubated for increasing periods of time in the cuvette of the aggregometer before adding ADP, and a significant decrease of aggregation, proportional to the length of incubation, was observed. Stirring of the PRP during the incubation period made these changes more evident.To measure the exact temperature of the PRP during incubation in the aggre- gometer, a thermocouple device was used. While the temperature of the cuvette holder was stable at 37° C, the PRP temperature itself increased exponentially, taking about ten minutes from the beginning of the incubation to reach the value of 37° C. The above results have a practical significance in the reproducibility of the platelet aggregation test in vitro and acquire particular value when the effect of inhibitors of ADP induced platelet aggregation is studied.Experiments carried out with three anti-aggregating agents (acetyl salicyclic acid, dipyridamole and metergoline) have shown that the incubation conditions which influence both the effect of the drugs on platelets and the ADP breakdown in plasma must be strictly controlled.

The Effects of Therapy with Oestriol Succinate and Ethinyl Oestradiol on the Haemostatic Mechanism in Post-Menopausal Women

1976 ◽  
Vol 35 (02) ◽  
pp. 403-414 ◽  
Author(s):  
Terence Davies ◽  
Gillian Fieldhouse ◽  
George P. McNicol
Keyword(s):  
Coagulation Factors ◽  
Factor Vii ◽  
Oestrogen Therapy ◽  
Qualitative And Quantitative ◽  
Lysis Activity ◽  
Menopausal Women ◽  
Increased Sensitivity ◽  
Post Menopausal ◽  
Incremental Increase ◽  
Ethinyl Oestradiol

SummaryThe effects on the haemostatic mechanism of oestrogen therapy, given to prevent bone loss in post-menopausal women, have been investigated. Oestriol succinate was given orally to 10 women at a level of 2 mg/day for 1 month and for a further 3 months with incremental increase of 2 mg each month. 6 of the 10 women were subsequently treated with 25 μg/day orally of ethinyl oestradiol. Oestriol succinate therapy resulted in a small increase in the level of factor VII, a decrease in factor VIII concentration and increased sensitivity of platelets to aggregating agents. Ethinyl oestradiol treatment resulted in much more widespread changes with marked increases in coagulation factors VII, VIII, IX and X, decreased levels of antithrombin and dramatic increases in circulating plasminogen levels and euglobulin lysis activity. The data suggested that the nature of oestrogens employed therapeutically is important in determining the qualitative and quantitative effect of oestrogen therapy on components of the haemostatic mechanism.

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