Effect of temperature & salt concentration on salt tolerant nitrate-perchlorate reducing bacteria: Nitrate degradation kinetics

2015 ◽  
Vol 83 ◽  
pp. 345-353 ◽  
Author(s):  
Shelir Ebrahimi ◽  
Thi Hau Nguyen ◽  
Deborah J. Roberts
Keyword(s):  
Salt Concentration ◽  
Degradation Kinetics ◽  
Effect Of Temperature ◽  
Salt Tolerant ◽  
Nitrate Degradation ◽  
Reducing Bacteria

scholarly journals Salt Tolerance of Three Tree Species Differing in Native Habitats and Leaf Traits

HortScience ◽  
2014 ◽  
Vol 49 (9) ◽  
pp. 1194-1200
Author(s):  
Nisa Leksungnoen ◽  
Roger K. Kjelgren ◽  
Richard C. Beeson ◽  
Paul G. Johnson ◽  
Grant E. Cardon ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Gas Exchange ◽  
Salt Concentration ◽  
Leaf Traits ◽  
Leaf Damage ◽  
Urban Landscapes ◽  
Salt Tolerant ◽  
Native Habitat ◽  
Saline Habitats ◽  
Salinity Levels

We investigated if salt tolerance can be inferred from observable cues based on a woody species’ native habitat and leaf traits. Such inferences could improve species selection for urban landscapes constrained by soils irrigated with reclaimed water. We studied the C3 tree species Acer grandidentatum Nutt. (canyon maple; xeric-non-saline habitat) that was hypothesized to have some degree of salt tolerance based on its semiarid but non-saline native habitat. We compared it with A. macrophyllum Pursh. (bigleaf maple) from mesic/riparian-non-saline habitats with much larger leaves and Eucalyptus camaldulensis Dehnh. (eucalyptus/red gum) from mesic-saline habitats with schlerophyllous evergreen leaves. Five levels of increasing salt concentrations (non-saline control to 12 dS·m−1) were applied over 5 weeks to container-grown seedling trees in two separate studies, one in summer and the other in fall. We monitored leaf damage, gas exchange, and hydric behavior as measures of tree performance for 3 weeks after target salinity levels were reached. Eucalyptus was the most salt-tolerant among the species. At all elevated salinity levels, eucalyptus excluded salt from its root zone, unlike either maple species. Eucalyptus maintained intact, undamaged leaves with no effect on photosynthesis but with minor reductions in stomatal conductance (gS). Conversely, bigleaf maple suffered increasing leaf damage, nearly defoliated at the highest levels, with decreasing gas exchange as salt concentration increased. Canyon maple leaves were not damaged and gas exchange was minimally affected at 3 dS·m−1 but showed increasing damage at higher salt concentration. Salt-tolerant eucalyptus and riparian bigleaf maple framed canyon maple’s moderate salt tolerance up to 3 dS·m−1 that appears related to seasonal soil drying in its semiarid native habitat. These results highlight the potential to infer a degree of salt tolerance from either native habitat or known drought tolerance in selecting plant species for urban landscapes limited by soil salinity or brackish irrigation water. Observable cues such as xeri-morphic leaf traits may also provide visual evidence of salt tolerance.

scholarly journals Degradation kinetics during storage of vitamins and antioxidants in coconut powder

DYNA ◽  
2020 ◽  
Vol 87 (213) ◽  
pp. 61-68
Author(s):  
Juan Carlos Lucas Aguirre ◽  
German Antonio Giraldo Giraldo ◽  
Misael Cortés Rodríguez
Keyword(s):  
Antioxidant Activity ◽  
Storage Temperature ◽  
Degradation Kinetics ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Storage Conditions ◽  
Treatment Temperature ◽  
Effect Of Temperature ◽  
Order Kinetic ◽  
Degradation Kinetic

Degradation kinetic parameters in vitamins and antioxidants in coconut powder fortified with functionally active compounds (CP+FAC) during storage represents a valuable tool to predict the product’s shelf life. The aim of this research was to evaluate the degradation kinetics during storage of vitamins (C, D3, and E), total phenols, and properties associated to antioxidant activity. Vitamins were quantified via high-resolution liquid chromatography and the antioxidant activity through DPPH and ABTS free radical scavenging activity. An experimental design was used with two-factor factorial design: 1) storage time (tS) and 2) treatment: temperature (TA) - type of packaging (N2 and atmospheric air), where the dependent variables were adjusted to zero-, first-, and second-order kinetic models. In general, losses of FAC were significant with respect to the factors evaluated and their interactions, with minor changes at lower TA and packaged with N2, indicating that the degradation kinetics of the FAC is slower under these storage conditions. Increased storage temperature reduced FACstability, where the Arrhenius equation was able to quantify the effect of temperature of the rate of deterioration reactions of the FAC.

scholarly journals Salinity Tolerance of Tamarind, Barbados Cherry, and Zapote Seedlings

HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 603A-603
Author(s):  
Bielinski M. Santos ◽  
Jose P. Morales-Payan
Keyword(s):  
Dominican Republic ◽  
Salinity Tolerance ◽  
Salt Concentration ◽  
Saline Water ◽  
Biomass Accumulation ◽  
Tamarindus Indica ◽  
Salt Tolerant ◽  
Irrigation Frequency ◽  
Linear Relationships

Nursery experiments were conducted in the Dominican Republic to determine the tolerance of tamarind (Tamarindus indica), acerola or Barbados cherry (Malpighia punicifolia), and zapote (Calocarpum sapota) irrigation with saline water (0, 2, 4, 6, and 8 dS/m) at different frequencies (every 24, 48, and 72 hours) during 60 days. Results indicate that tamarind was the less salt-sensitive and zapote the less salt-tolerant of the three species. Linear relationships were found between salt concentration and growth, with biomass accumulation decreasing as salinity and irrigation frequency increased.

scholarly journals Phycocyanin Thermo-photostability: an Accelerated Life-test Analysis

2020 ◽  
Vol 64 (3) ◽  
Author(s):  
Froylan M. E. Escalante ◽  
Daniel A. Pérez-Rico ◽  
Jorge Luis Alarcón-Jiménez ◽  
Escarlett González-Morales ◽  
Luis Felipe Guerra-Álvarez ◽  
...  
Keyword(s):  
Degradation Kinetics ◽  
Storage Conditions ◽  
Accelerated Life Test ◽  
Effect Of Temperature ◽  
Order Kinetic ◽  
Life Test ◽  
Time Data ◽  
Test Analysis ◽  
Accelerated Life ◽  
Degradation Ratio

Abstract. Phycocyanin is a natural blue colorant with antioxidant activity which can be safely used in food, however its rapid degradation is still a concern for food manufacturing. Phycocyanin is easily degraded when exposed to mid-temperatures and/or light. Several studies have been stablished the degradation kinetics of aqueous solutions evaluating temperature or light as accelerating factors using a first order kinetic model and, both factors have been studied by separate or fixing one of them to evaluate the combined effect. The aim of this work was to develop an empirical model able to predict the effect of temperature and light combined in the degradation ratio of this pigment at selected storage conditions. We have tested five correlation models to fit temperature, light and time data to the degradation ratio of the phycocyanin; these were statistically tested to select the more appropriate. This is a novelty in the study of accelerated life-test analysis of phycocyanin, since most of the models are based on one accelerating variable at the time and the relationship between accelerating variables has not been explored before. We were able to develop a methodology to evaluate the effect of two accelerating life factors at once using CPC as model which is highly precise and easy to apply. Resumen. La ficocianina es un pigmento natural color azul con actividad antioxidante que puede utilizarse de manera segura en alimentos, sin embargo, su rápida degradación sigue siendo un problema para su uso en alimentos. La ficocianina se degrada fácilmente cuando se expone a temperaturas medias o a la luz. Algunos estudios han establecido la cinética de degradación de las soluciones evaluando la temperatura o la luz como factores de aceleración usando modelos cinéticos de primer orden. Además, ambos factores han sido estudiados por separado o fijando uno de ellos para evaluar el efecto combinado. El objetivo de este trabajo fue desarrollar un modelo empírico capaz de predecir el efecto de la temperatura y la iluminación en forma combinada sobre la velocidad de degradación de la ficocianina a las condiciones de almacenamiento seleccionadas. Se probaron cinco modelos de correlación para ajustar los datos de temperatura, luz y tiempo a la velocidad de degradación de la ficocianina; dichos modelos fueron probados estadísticamente para determinar el más adecuado. Esta es una novedad en el estudio de los análisis de pruebas de vida acelerada de la ficocianina, dado que la mayoría de los modelos se basan en una sola variable acelerante a la vez y, no se han explorado las relaciones entre las variables de aceleración. Fuimos capaces de desarrollar una metodología altamente precisa y sencilla para evaluar el efecto de dos factores simultáneos de aceleración de la vida de la ficocianina C como modelo.

Effect of Temperature and Salt Concentration on Rheological Behaviour of Surfactin

2019 ◽  
Author(s):  
S. M. Salihu ◽  
A. J. Abubakar ◽  
B. Meisam ◽  
U. A. Emmanuel ◽  
K. Y. Hassan ◽  
...  
Keyword(s):  
Salt Concentration ◽  
Rheological Behaviour ◽  
Effect Of Temperature

scholarly journals Sulfate-dependent acetate oxidation under extremely natron-alkaline conditions by syntrophic associations from hypersaline soda lakes

Microbiology ◽  
2014 ◽  
Vol 160 (4) ◽  
pp. 723-732 ◽  
Author(s):  
Dimitry Y. Sorokin ◽  
Ben Abbas ◽  
Tatjana P. Tourova ◽  
Boris K. Bumazhkin ◽  
Tatjana V. Kolganova ◽  
...  
Keyword(s):  
Soda Lakes ◽  
Minor Component ◽  
Acetate Oxidation ◽  
Salt Tolerant ◽  
Sulfate Reducing ◽  
Kulunda Steppe ◽  
Alkaline Conditions ◽  
Extreme Salinity ◽  
A Minor ◽  
Reducing Bacteria

So far, anaerobic sulfate-dependent acetate oxidation at high pH has only been demonstrated for a low-salt-tolerant syntrophic association of a clostridium ‘Candidatus Contubernalis alkalaceticum’ and its hydrogenotrophic sulfate-reducing partner Desulfonatronum cooperativum. Anaerobic enrichments at pH 10 inoculated with sediments from hypersaline soda lakes of the Kulunda Steppe (Altai, Russia) demonstrated the possibility of sulfate-dependent acetate oxidation at much higher salt concentrations (up to 3.5 M total Na+). The most salt-tolerant purified cultures contained two major components apparently working in syntrophy. The primary acetate-fermenting component was identified as a member of the order Clostridiales forming, together with ‘Ca. Contubernalis alkalaceticum’, an independent branch within the family Syntrophomonadaceae. A provisional name, ‘Ca. Syntrophonatronum acetioxidans’, is suggested for the novel haloalkaliphilic clostridium. Two phylotypes of extremely haloalkaliphilic sulfate-reducing bacteria of the genus Desulfonatronospira were identified as sulfate-reducing partners in the acetate-oxidizing cultures under extreme salinity. The dominant phylotype differed from the two species of Desulfonatronospira described so far, whilst a minor component belonged to Desulfonatronum thiodismutans. The results proved that, contrary to previous beliefs, sulfate-dependent acetate oxidation is possible, albeit very slowly, in nearly saturated soda brines.

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