Decomposition products of cylindrospermopsin – a cyanotoxin produced by Raphidiopsis raciborskii (Woloszynska)

2019 ◽  
Vol 48 (3) ◽  
pp. 227-235 ◽  
Author(s):  
Michal Adamski ◽  
Paweł Żmudzki ◽  
Jan Bialczyk ◽  
Ariel Kaminski ◽  
Ewelina Chrapusta-Srebrny ◽  
...  
Keyword(s):  
High Temperature ◽  
Environmental Factors ◽  
Vibrio Fischeri ◽  
Freshwater Species ◽  
Decomposition Products ◽  
Structural Modifications ◽  
Toxicity Potential ◽  
Alkaline Conditions ◽  
Living Organisms ◽  
Guanidine Moiety

Abstract Toxins produced by cyanobacteria (cyanotoxins) and released into water have become a serious problem worldwide due to the increasing morbidity and mortality of living organisms they have caused. The ability to synthesize the cytotoxic alkaloid cylindrospermopsin (CYN) has been demonstrated in several freshwater species of cyanobacteria. CYN is highly chemically stable under environmental factors and decomposes only under alkaline conditions, where it forms derivatives. The toxicity potential of the decomposition products formed at pH 10 combined with high temperature (100°C) or UV-B irradiation (36 μmol m−2 s−1) has been research based on the crustacean Thamnocephalus platyurus (Thamnotoxkit FTM) and bacteria Vibrio fischeri (Deltatox® II) bioassays. This paper is a continuation and completion of our previous experiments and the obtained results showed that the applied conditions contributed to the decomposition of the CYN molecule to non-toxic products and its structural modifications by separating the uracil ring or/and the sulfate group from the tricyclic guanidine moiety, leading to a reduction in its toxicity. To the best of our knowledge, this is the first report describing the toxicity of CYN decomposition products formed under alkaline conditions combined with boiling temperature or UV-B irradiation.

scholarly journals An unknown oxidative metabolism substantially contributes to soil CO<sub>2</sub> emissions

2013 ◽  
Vol 10 (2) ◽  
pp. 1155-1167 ◽  
Author(s):  
V. Maire ◽  
G. Alvarez ◽  
J. Colombet ◽  
A. Comby ◽  
R. Despinasse ◽  
...  
Keyword(s):  
High Temperature ◽  
Environmental Factors ◽  
Soil Respiration ◽  
Oxidative Metabolism ◽  
Global Carbon Cycle ◽  
Toxic Compounds ◽  
C Cycle ◽  
Intracellular Metabolism ◽  
Living Organisms ◽  
Global Carbon

Abstract. The respiratory release of CO2 from soils is a major determinant of the global carbon cycle. It is traditionally considered that this respiration is an intracellular metabolism consisting of complex biochemical reactions carried out by numerous enzymes and co-factors. Here we show that the endoenzymes released from dead organisms are stabilised in soils and have access to suitable substrates and co-factors to permit function. These enzymes reconstitute an extracellular oxidative metabolism (EXOMET) that may substantially contribute to soil respiration (16 to 48% of CO2 released from soils in the present study). EXOMET and respiration from living organisms should be considered separately when studying effects of environmental factors on the C cycle because EXOMET shows specific properties such as resistance to high temperature and toxic compounds.

scholarly journals An unknown respiration pathway substantially contributes to soil CO<sub>2</sub> emissions

2012 ◽  
Vol 9 (7) ◽  
pp. 8663-8691 ◽  
Author(s):  
V. Maire ◽  
G. Alvarez ◽  
J. Colombet ◽  
A. Comby ◽  
R. Despinasse ◽  
...  
Keyword(s):  
High Temperature ◽  
Environmental Factors ◽  
Soil Respiration ◽  
Oxidative Metabolism ◽  
Global Carbon Cycle ◽  
C Cycle ◽  
Intracellular Enzymes ◽  
Intracellular Metabolism ◽  
Living Organisms ◽  
Global Carbon

Abstract. The respiratory release of CO2 from soils is a major determinant of the global carbon cycle. It is traditionally considered that this respiration is an intracellular metabolism consisting of complex biochemical reactions carried out by numerous enzymes and co-factors. Here we show that the intracellular enzymes released from dead organisms are stabilized in soils and have access to suitable substrates and co-factors to permit function. These enzymes reconstitute an extracellular oxidative metabolism (Exomet) that may substantially contribute to soil respiration (16 to 48% of CO2 released from soils in the present study). Exomet and respiration from living organisms should be considered separately when studying effects of environmental factors on the C cycle because Exomet shows specific properties such as resistance to high temperature and toxics.

scholarly journals Systemic Infection by Fusarium verticillioides in Maize Plants Grown Under Three Temperature Regimes

Plant Disease ◽  
2008 ◽  
Vol 92 (12) ◽  
pp. 1695-1700 ◽  
Author(s):  
A. Murillo-Williams ◽  
G. P. Munkvold
Keyword(s):  
High Temperature ◽  
Environmental Factors ◽  
Fusarium Verticillioides ◽  
Systemic Infection ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Kernel Infection ◽  
Temperature Regimes ◽  
Maize Plants ◽  
Systemic Development

Fusarium verticillioides causes seedling decay, stalk rot, ear rot, and mycotoxin contamination (primarily fumonisins) in maize. Systemic infection of maize plants by F. verticillioides can lead to kernel infection, but the frequency of this phenomenon has varied widely among experiments. Variation in the incidence of systemic infection has been attributed to environmental factors. In order to better understand the influence of environment, we investigated the effect of temperature on systemic development of F. verticillioides during vegetative and reproductive stages of plant development. Maize seeds were inoculated with a green fluorescent protein-expressing strain of F. verticillioides, and grown in growth chambers under three different temperature regimes. In the vegetative-stage and reproductive-stage experiments, plants were evaluated at tasseling (VT stage), and at physiological maturity (R6 stage), respectively. Independently of the temperature treatment, F. verticillioides was reisolated from nearly 100% of belowground plant tissues. Frequency of reisolation of the inoculated strain declined acropetally in aboveground internodes at all temperature regimes. At VT, the high-temperature treatment had the highest systemic development of F. verticillioides in aboveground tissues. At R6, incidence of systemic infection was greater at both the high- and low-temperature regimes than at the average-temperature regime. F. verticillioides was isolated from higher internodes in plants at R6, compared to stage VT. The seed-inoculated strain was recovered from kernels of mature plants, although incidence of kernel infection did not differ significantly among treatments. During the vegetative growth stages, temperature had a significant effect on systemic development of F. verticillioides in stalks. At R6, the fungus reached higher internodes in the high-temperature treatment, but temperature did not have an effect on the incidence of kernels (either symptomatic or asymptomatic) or ear peduncles infected with the inoculated strain. These results support the role of high temperatures in promoting systemic infection of maize by F. verticillioides, but plant-to-seed transmission may be limited by other environmental factors that interact with temperature during the reproductive stages.

Diffusivity, Solubility and Speciation of Sulphur in Silicate Melts

2006 ◽  
Vol 46 ◽  
pp. 93-97 ◽  
Author(s):  
J. Stelling ◽  
Harald Behrens ◽  
Joachim Deubener ◽  
Stefan Mangold ◽  
Joerg Goettlicher
Keyword(s):  
High Temperature ◽  
Electron Microprobe ◽  
Industrial Production ◽  
Silicate Melts ◽  
Viscosity Data ◽  
Decomposition Products ◽  
X Ray ◽  
Diffusion Couple Technique ◽  
X Ray Absorption ◽  
Diffusion Profiles

Diffusion and solubility of sulphur have important effects on the degassing of silicate melts. Both properties are closely related to the structural incorporation of sulphur in the melt. Depending on the oxygen fugacity, sulphur can be present as sulphide (S2-), sulphite (S4+) or sulphate (S6+). Sulphates play an important role in the industrial production of glasses especially in the fining process. The decomposition products of sulphate amass in bubbles which ascend and homogenize the melt. Structural incorporation of sulphur in glasses is studied by XANES (X-ray Absorption Near Edge Spectroscopy). Diffusion of sulphur is investigated in simple silicate systems using the diffusion couple technique. First diffusion profiles were measured in sodium trisilicate glasses by electron microprobe. The results indicate that sulphur diffusivity in high temperature melts is close to the Eyring diffusivity calculated from viscosity data.

scholarly journals Formation of Elements and Compounds in Space in Early Universe

2016 ◽  
Vol 8 (6) ◽  
pp. 86
Author(s):  
Abdul L. Bhuiyan
Keyword(s):  
Dark Matter ◽  
High Temperature ◽  
Early Universe ◽  
High Speed ◽  
Virtual State ◽  
Speed Of Light ◽  
Electron Positron ◽  
Living Organisms ◽  
The Universe

<p class="1Body">At the end of the period of contraction of the universe, all objects transform into gravity particles such as photons and electron- positron pairs which exist in virtual state in spacetime at an extremely high temperature. These particles move with extremely high speed comparable to the speed of light. As the early universe starts cooling, the speed of the particles starts to decrease when photons and electron- positron pairs move out of spacetime and appear as real particles. As the temperature continues to fall due to cooling, the electron- positron pairs start forming quarks (u and d) while simultaneously the energy of photons transform into dark matter. The u quarks and d quarks then continue to form nuclei of different elements including radio elements. Simultaneously, the lighter elements such as hydrogen, nitrogen, carbon, oxygen, phosphorus, etc. form the precursors to DNAs and RNAs of living organisms.</p>

EFFECT OF ENVIRONMENT ON BROMOBUTYL RUBBER–STEEL ADHESION

2019 ◽  
Vol 93 (2) ◽  
pp. 429-444 ◽  
Author(s):  
Essi Sarlin ◽  
Ari Rosling ◽  
Mari Honkanen ◽  
Mari Lindgren ◽  
Mira Juutilainen ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
High Temperature ◽  
Relative Humidity ◽  
Environmental Factors ◽  
Adhesive Layer ◽  
Metal Structure ◽  
Adhesive System ◽  
Metal Interface ◽  
Weakest Link ◽  
Industry Sectors

ABSTRACT Optimizing the maintenance cycles of rubber-lined components is of great importance. Especially for the industry sectors operating under demanding conditions, challenges in the lifetime evaluation of rubber linings may cause apparent premature failures. Thus, understanding the effect of environmental factors on the performance and durability of rubber linings, as well as on the weakest links of the structure in certain environments, is essential. The performances of bromobutyl rubber and rubber–steel interfaces after exposure to different environments, namely, high temperature (95 °C), moisture (95% relative humidity and immersion), and sulfuric acid (solution with 75 g/L of acid) were investigated. The weakest link of the rubber–metal structure and, consequently, the location of the fracture were mostly within the adhesive layer or at the primer–metal interface. However, the most degraded component of the adhesive system depends on the aging environments.

High Pressure Reactions in the Systems Zn3As2—As and Cd3As2—As

1975 ◽  
Vol 30 (9-10) ◽  
pp. 688-695 ◽  
Author(s):  
J. B. Clark ◽  
Klaus-Jürgen Range
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Temperature Region ◽  
High Temperature Region ◽  
Orthorhombic Space Group ◽  
Decomposition Products ◽  
High Pressure And Temperature ◽  
Space Group ◽  
Group D

ZnAs2 and CdAs2 decompose at high pressure and temperature. The determined decomposition boundaries are presented. From synthesis experiments in the systems Cd3As2—As and Zn3As2—As, the decomposition products were found to be mixtures of CdAs + As and ZnAs + As. The high pressure phases CdAs and ZnAs are orthorhombic, space group D152h — Pbca, with αo = 5.993 A, bo = 7.819 A, co = 8.010 Å and αo = 5.679 A, bo = 7.277 A, co = 7.559 Å, respectively. Further phases are recovered from the high temperature region at high pressure.

scholarly journals Natural variations of SLG1 confer high-temperature tolerance in indica rice

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yufang Xu ◽  
Li Zhang ◽  
Shujun Ou ◽  
Ruci Wang ◽  
Yueming Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Indica Rice ◽  
High Temperature Stress ◽  
Temperature Tolerance ◽  
Cultivated Rice ◽  
Rice Varieties ◽  
Coding Regions ◽  
High Temperature Tolerance ◽  
Living Organisms

Abstract With global warming and climate change, breeding crop plants tolerant to high-temperature stress is of immense significance. tRNA 2-thiolation is a highly conserved form of tRNA modification among living organisms. Here, we report the identification of SLG1 (Slender Guy 1), which encodes the cytosolic tRNA 2-thiolation protein 2 (RCTU2) in rice. SLG1 plays a key role in the response of rice plants to high-temperature stress at both seedling and reproductive stages. Dysfunction of SLG1 results in plants with thermosensitive phenotype, while overexpression of SLG1 enhances the tolerance of plants to high temperature. SLG1 is differentiated between the two Asian cultivated rice subspecies, indica and japonica, and the variations at both promoter and coding regions lead to an increased level of thiolated tRNA and enhanced thermotolerance of indica rice varieties. Our results demonstrate that the allelic differentiation of SLG1 confers indica rice to high-temperature tolerance, and tRNA thiolation pathway might be a potential target in the next generation rice breeding for the warming globe.

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