Effects of different metabolic pathways and environmental parameters on Cr isotope fractionation during Cr(VI) reduction by extremely thermophilic bacteria

2019 ◽  
Vol 256 ◽  
pp. 135-146 ◽  
Author(s):  
Guojun Chen ◽  
Yanan Bai ◽  
Raymond Jianxiong Zeng ◽  
Liping Qin
Keyword(s):  
Metabolic Pathways ◽  
Isotope Fractionation ◽  
Thermophilic Bacteria ◽  
Environmental Parameters

scholarly journals Nyitni vagy nem nyitni? – Pilisi barlangok szellőzöttsége a geokémiai adatok tükrében

2021 ◽  
Vol 145 (3) ◽  
pp. 224-231
Keyword(s):  
Stable Isotope ◽  
Environmental Conditions ◽  
Isotope Fractionation ◽  
Environmental Parameters ◽  
Basic Research ◽  
Geochemical Analysis ◽  
Cave System ◽  
Cave Environment ◽  
Carbonate Formations ◽  
The Given

Speleothem formations are one of the most important and informative objects in paleoclimatological research. However, in order to interpret the data that reflect environmental conditions, we have to know the operation of the given cave, and it should be determined how the composition of the carbonate formed at the given site is related to the changes in the environmental parameters. The study presents the results of stable isotope geochemical analysis of speleothem formations and carbonate precipitated on glass plates collected in the Vacska Cave (Pilis Hills). The youngest layer of carbonate formations, formed in the last 1-2 decades, shows an isotope fractionation sign indicating strong ventilation, with the exception of a single site farthest from the entrance to the cave. The isotope shift was also accompanied by a change in carbonate fabric. Preceding the fabric change, the carbonate of the speleothem formations did not show ventilation-related shifts in the isotope compositions, suggesting that the exploration and opening of the cave areas may have caused the change. Based on this, we recommend the installation of local closures in the Vacska Cave and in the entire Ariadne cave system. The study provides a good example of how the results of basic research can be utilized in practical environmental protection, in the preservation of a strictly protected cave environment.

scholarly journals Possible Mechanisms of Biological Effects Observed in Living Systems during 2H/1H Isotope Fractionation and Deuterium Interactions with Other Biogenic Isotopes

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4101 ◽  
Author(s):  
Alexander Basov ◽  
Liliya Fedulova ◽  
Ekaterina Vasilevskaya ◽  
Stepan Dzhimak
Keyword(s):  
Metabolic Pathways ◽  
Intercellular Space ◽  
Isotope Fractionation ◽  
Biological Effects ◽  
Experimental Studies ◽  
Living Systems ◽  
Chemical Bonds ◽  
Molecular Effects ◽  
Tunnel Effects ◽  
New Hypothesis

This article presents the original descriptions of some recent physics mechanisms (based on the thermodynamic, kinetic, and quantum tunnel effects) providing stable 2H/1H isotope fractionation, leading to the accumulation of particular isotopic forms in intra- or intercellular space, including the molecular effects of deuterium interaction with 18O/17O/16O, 15N/14N, 13C/12C, and other stable biogenic isotopes. These effects were observed mainly at the organelle (mitochondria) and cell levels. A new hypothesis for heavy nonradioactive isotope fractionation in living systems via neutron effect realization is discussed. The comparative analysis of some experimental studies results revealed the following observation: “Isotopic shock” is highly probable and is observed mostly when chemical bonds form between atoms with a summary odd number of neutrons (i.e., bonds with a non-compensated neutron, which correspond to the following equation: Nn − Np = 2k + 1, where k ϵ Z, k is the integer, Z is the set of non-negative integers, Nn is number of neutrons, and Np is number of protons of each individual atom, or in pair of isotopes with a chemical bond). Data on the efficacy and metabolic pathways of the therapy also considered 2H-modified drinking and diet for some diseases, such as Alzheimer’s disease, Friedreich’s ataxia, mitochondrial disorders, diabetes, cerebral hypoxia, Parkinson’s disease, and brain cancer.

Heterotrophic nitrification by a thermophilicBacillusspecies as influenced by different culture conditions

2000 ◽  
Vol 46 (5) ◽  
pp. 465-473 ◽  
Author(s):  
Geneviève Mével ◽  
Daniel Prieur
Keyword(s):  
Thermophilic Bacteria ◽  
Culture Media ◽  
Heterotrophic Bacterium ◽  
Environmental Parameters ◽  
Growth Conditions ◽  
Culture Conditions ◽  
Heterotrophic Nitrification ◽  
Nitrite Reduction ◽  
Carbon Substrate ◽  
Bacterium Bacillus

The nitrification activity of a thermophilic heterotrophic bacterium, Bacillus MS30 isolated from a deep-sea hydrothermal vent, was studied under various growth conditions. Nitrification was estimated from the nitrogen balance calculations in the culture media. The results showed that this isolate actively nitrified in culture conditions similar to those prevailing in hydrothermal sites. Therefore, its ecological significance was considered. In standard aerobic conditions, MS30 produced nitrite from ammonia and acetate (1.13 µmol NO2-·mg-1dry wt), but nitrate was never produced, and a low nitrite reduction was often observed. Higher nitrification activities were observed in defined optimal conditions (simple carbon substrate, 65°C, pH 7.5, and 15 g sea salts · L-1). In addition, discrepancies between the optima for growth and nitrification were observed, showing the ability of MS30 to adapt to changing environmental conditions typical of hydrothermal sites.Key words: thermophilic bacteria, heterotrophic nitrification, environmental parameters.

scholarly journals Impact of metabolic pathways and salinity on the hydrogen isotope ratios of haptophyte lipids

2019 ◽  
Author(s):  
Gabriella M. Weiss ◽  
David Chivall ◽  
Sebastian Kasper ◽  
Hideto Nakamura ◽  
Fiz da Costa ◽  
...  
Keyword(s):  
Metabolic Pathways ◽  
Hydrogen Isotope ◽  
Environmental Parameters ◽  
Isotope Ratios ◽  
Similar Response ◽  
Batch Cultures ◽  
Group Iii ◽  
First Order ◽  
Hydrogen Isotope Ratios ◽  
Long Chain

Abstract. Hydrogen isotope ratios of biomarkers have been shown to reflect water isotope ratios, and in some cases correlate significantly with salinity. The δ2H-salinity relationship is best studied for long-chain alkenones, biomarkers for haptophyte algae, and is known to be influenced by a number of different environmental parameters. It is not fully known why δ2H ratios of lipids retain a correlation to salinity, and whether this is a general feature for other lipids produced by haptophyte algae. Here, we analyzed δ2H ratios of three fatty acids, brassicasterol, long-chain C37 alkenones and phytol from three different haptophyte species grown over a range of salinities. Lipids synthesized in the cytosol, or relying on precursors of cytosolic origin, show a correlation between their δ2H ratios and salinity. In contrast, biosynthesis in the chloroplast, or utilizing precursors created in the chloroplast, yields lipids that do not show a correlation between δ2H ratios and salinity. This leads to the conclusion that location of metabolism is the first-order control on the salinity signal retained in δ2H ratios of certain lipids. Additionally, we found that δ2H ratios of alkenones from batch cultures of the Group II haptophyte species Tisochrysis lutea correlate positively with temperature, contrary to findings from cultures of Group III haptophytes, but retain a similar response to nutrient availability in line with other Group III haptophytes.

Non-statistical isotope fractionation as a novel “retro-biosynthetic” approach to understanding alkaloid metabolic pathways

2017 ◽  
Vol 20 ◽  
pp. 499-506 ◽  
Author(s):  
Richard J. Robins ◽  
Katarzyna M. Romek ◽  
Gérald S. Remaud ◽  
Piotr Paneth
Keyword(s):  
Metabolic Pathways ◽  
Isotope Fractionation

Accelerating Metabolic Pathways Simulation using GPUs

2010 ◽  
Author(s):  
Sohan Lal ◽  
Kolin Paul ◽  
James Gomes
Keyword(s):  
Metabolic Pathways

Mapping metabolic pathways in chemical property space paves the way for new leishmanicidals

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
E Vikeved ◽  
R Buonfiglio ◽  
T Kogej ◽  
A Backlund
Keyword(s):  
Chemical Property ◽  
Metabolic Pathways ◽  
Property Space ◽  
The Way

HUBUNGAN KEPADATAN BIVALVIA DENGAN PARAMETER LINGKUNGAN DI PESISIR TANJUNG PURA KABUPATEN BANGKA TENGAH

2020 ◽  
Vol 13 (2) ◽  
pp. 112-121
Author(s):  
Sudiyar . ◽  
Okto Supratman ◽  
Indra Ambalika Syari
Keyword(s):  
Negative Impact ◽  
Principal Component ◽  
Environmental Parameters ◽  
Data Retrieval ◽  
Distribution Patterns ◽  
Random System ◽  
System Method ◽  
Relationship Of ◽  
The Relationship ◽  
Anadara Granosa

The destructive fishing feared will give a negative impact on the survival of this organism. This study aims to analyze the density of bivalves, distribution patterns, and to analyze the relationship of bivalves with environmental parameters in Tanjung Pura village. This research was conducted in March 2019. The systematic random system method was used for collecting data of bivalves. The collecting Data retrieval divided into five research stasions. The results obtained 6 types of bivalves from 3 families and the total is 115 individuals. The highest bivalve density is 4.56 ind / m², and the lowest bivalves are located at station 2,1.56 ind / m²,  The pattern of bivalve distribution in the Coastal of Tanjung Pura Village is grouping. The results of principal component analysis (PCA) showed that Anadara granosa species was positively correlated with TSS r = 0.890, Dosinia contusa, Anomalocardia squamosa, Mererix meretrix, Placamen isabellina, and Tellinella spengleri were positively correlated with currents r = 0.933.

Recirculation versus flow-through rainbow trout laboratory Flavobacterium columnare challenge

2020 ◽  
Vol 139 ◽  
pp. 213-221
Author(s):  
C Birkett ◽  
R Lipscomb ◽  
T Moreland ◽  
T Leeds ◽  
JP Evenhuis
Keyword(s):  
Rainbow Trout ◽  
Environmental Parameters ◽  
Cumulative Effects ◽  
Flavobacterium Columnare ◽  
Replacement Rate ◽  
Bacterial Concentration ◽  
Water Replacement ◽  
Dose Concentration ◽  
Flow Through ◽  
And Control

Flavobacterium columnare immersion challenges are affected by water-related environmental parameters and thus are difficult to reproduce. Whereas these challenges are typically conducted using flow-through systems, use of a recirculating challenge system to control environmental parameters may improve reproducibility. We compared mortality, bacterial concentration, and environmental parameters between flow-through and recirculating immersion challenge systems under laboratory conditions using 20 rainbow trout families. Despite identical dose concentration (1:75 dilution), duration of challenge, lot of fish, and temperature, average mortality in the recirculating system (42%) was lower (p < 0.01) compared to the flow-through system (77%), and there was low correlation (r = 0.24) of family mortality. Mean days to death (3.25 vs. 2.99 d) and aquaria-to-aquaria variation (9.6 vs. 10.4%) in the recirculating and flow-through systems, respectively, did not differ (p ≥ 0.30). Despite 10-fold lower water replacement rate in the recirculating (0.4 exchanges h-1) compared to flow-through system (4 exchanges h-1), differences in bacterial concentration between the 2 systems were modest (≤0.6 orders of magnitude) and inconsistent throughout the 21 d challenge. Compared to the flow-through system, dissolved oxygen during the 1 h exposure and pH were greater (p ≤ 0.02), and calcium and hardness were lower (p ≤ 0.03), in the recirculating system. Although this study was not designed to test effects of specific environmental parameters on mortality, it demonstrates that the cumulative effects of these parameters result in poor reproducibility. A recirculating immersion challenge model may be warranted to empirically identify and control environmental parameters affecting mortality and thus may serve as a more repeatable laboratory challenge model.

METABOLISM OF PREGNENOLONE-3-SULPHATE IN THE PERFUSED DOG LIVER

1965 ◽  
Vol 49 (3) ◽  
pp. 427-435 ◽  
Author(s):  
K. D. Voigt ◽  
J. Tamm ◽  
U. Volkwein ◽  
H. Schedewie
Keyword(s):  
Metabolic Pathways ◽  
Dog Liver ◽  
Steroid Conjugates

ABSTRACT Pregnenolone-sulphate (400 mg) was perfused through isolated dog livers. The following steroids were isolated in the perfusate: pregnenolone, progesterone, dehydroepiandrosterone, androst-5-ene-diol and the two steroid conjugates, i. e. pregnenolone-sulphate and dehydroepiandrosterone-sulphate. Two »free« steroids and one steroid conjugate could not be characterized. A tentative scheme for the metabolic pathways of pregnenolone-sulphate is presented.

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