scholarly journals Untargeted Metabolomics Investigation on Selenite Reduction to Elemental Selenium by Bacillus mycoides SeITE01

2021 ◽  
Vol 12 ◽  
Author(s):  
Greta Baggio ◽  
Ryan A. Groves ◽  
Roberto Chignola ◽  
Elena Piacenza ◽  
Alessandro Presentato ◽  
...  
Keyword(s):  
Time Course ◽  
Membrane Lipids ◽  
Untargeted Metabolomics ◽  
Elemental Selenium ◽  
Growth Stages ◽  
Bacterial Cells ◽  
Bacillus Mycoides ◽  
Thiol Compounds ◽  
Selenite Reduction ◽  
Signaling Strategies

Bacillus mycoides SeITE01 is an environmental isolate that transforms the oxyanion selenite (SeO32−) into the less bioavailable elemental selenium (Se0) forming biogenic selenium nanoparticles (Bio-SeNPs). In the present study, the reduction of sodium selenite (Na2SeO3) by SeITE01 strain and the effect of SeO32− exposure on the bacterial cells was examined through untargeted metabolomics. A time-course approach was used to monitor both cell pellet and cell free spent medium (referred as intracellular and extracellular, respectively) metabolites in SeITE01 cells treated or not with SeO32−. The results show substantial biochemical changes in SeITE01 cells when exposed to SeO32−. The initial uptake of SeO32− by SeITE01 cells (3h after inoculation) shows both an increase in intracellular levels of 4-hydroxybenzoate and indole-3-acetic acid, and an extracellular accumulation of guanosine, which are metabolites involved in general stress response adapting strategies. Proactive and defensive mechanisms against SeO32− are observed between the end of lag (12h) and beginning of exponential (18h) phases. Glutathione and N-acetyl-L-cysteine are thiol compounds that would be mainly involved in Painter-type reaction for the reduction and detoxification of SeO32− to Se0. In these growth stages, thiol metabolites perform a dual role, both acting against the toxic and harmful presence of the oxyanion and as substrate or reducing sources to scavenge ROS production. Moreover, detection of the amino acids L-threonine and ornithine suggests changes in membrane lipids. Starting from stationary phase (24 and 48h), metabolites related to the formation and release of SeNPs in the extracellular environment begin to be observed. 5-hydroxyindole acetate, D-[+]-glucosamine, 4-methyl-2-oxo pentanoic acid, and ethanolamine phosphate may represent signaling strategies following SeNPs release from the cytoplasmic compartment, with consequent damage to SeITE01 cell membranes. This is also accompanied by intracellular accumulation of trans-4-hydroxyproline and L-proline, which likely represent osmoprotectant activity. The identification of these metabolites suggests the activation of signaling strategies that would protect the bacterial cells from SeO32− toxicity while it is converting into SeNPs.

scholarly journals Time-Course Proteomic Analysis of Pseudomonas putida KT2440 during Mcl-Polyhydroxyalkanoate Synthesis under Nitrogen Deficiency

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 748 ◽  
Author(s):  
Justyna Możejko-Ciesielska ◽  
Agnieszka Mostek
Keyword(s):  
Pseudomonas Putida ◽  
Proteomic Analysis ◽  
Cellular Response ◽  
Time Course ◽  
Molecular Mechanisms ◽  
Nitrogen Deficiency ◽  
Growth Stages ◽  
Bacterial Cells ◽  
Pseudomonas Putida Kt2440 ◽  
Wide Range

Medium-chain-length polyhydroxyalkanoates (mcl-PHAs) have gained great attention as a new green alternative to petrochemical-derived polymers. Due to their outstanding material properties they can be used in a wide range of applications. Pseudomonas putida KT2440 is a metabolically versatile producer of mcl-polyhydroxyalkanoates. Although the metabolism of polyhydroxyalkanoate synthesis by this bacterium has been extensively studied, the comparative proteome analysis from three growth stages of Pseudomonas putida KT2440 cultured with oleic acid during mcl-PHA synthesis has not yet been reported. Therefore; the aim of the study was to compare the proteome of Pseudomonas putida KT2440 at different time points of its cultivation using the 2D difference gel electrophoresis (2D-DIGE) technique. The analyses showed that low levels of a nitrogen source were beneficial for mcl-PHA synthesis. Proteomic analysis revealed that the proteins associated with carbon metabolism were affected by nitrogen starvation and mcl-PHA synthesis. Furthermore, the induction of proteins involved in nitrogen metabolism, ribosome synthesis, and transport was observed, which may be the cellular response to stress related to nitrogen deficiency and mcl-PHA content in bacterial cells. To sum up; this study enabled the investigators to acquire a better knowledge of the molecular mechanisms underlying the induction of polyhydroxyalkanoate synthesis and accumulation in Pseudomonas putida KT2440 that could lead to improved strategies for PHAs in industrial production.

scholarly journals Transcriptional Response of Selenopolypeptide Genes and Selenocysteine Biosynthesis Machinery Genes inEscherichia coliduring Selenite Reduction

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Antonia Y. Tetteh ◽  
Katherine H. Sun ◽  
Chiu-Yueh Hung ◽  
Farooqahmed S. Kittur ◽  
Gordon C. Ibeanu ◽  
...  
Keyword(s):  
Growth Response ◽  
Inhibitory Concentration ◽  
Molecular Level ◽  
Transcriptional Response ◽  
Reduction Process ◽  
Elemental Selenium ◽  
Bacterial Cells ◽  
Quantitative Real Time Pcr ◽  
Selenite Reduction ◽  
E Coli

Bacteria can reduce toxic selenite into less toxic, elemental selenium (Se0), but the mechanism on how bacterial cells reduce selenite at molecular level is still not clear. We usedEscherichia colistrain K12, a common bacterial strain, as a model to study its growth response to sodium selenite (Na2SeO3) treatment and then used quantitative real-time PCR (qRT-PCR) to quantify transcript levels of threeE. coliselenopolypeptide genes and a set of machinery genes for selenocysteine (SeCys) biosynthesis and incorporation into polypeptides, whose involvements in the selenite reduction are largely unknown. We determined that 5 mM Na2SeO3treatment inhibited growth by∼50% while 0.001 to 0.01 mM treatments stimulated cell growth by∼30%. Under 50% inhibitory or 30% stimulatory Na2SeO3concentration, selenopolypeptide genes (fdnG,fdoG, andfdhF) whose products require SeCys but not SeCys biosynthesis machinery genes were found to be induced ≥2-fold. In addition, one sulfur (S) metabolic geneiscSand two previously reported selenite-responsive genessodAandgutSwere also induced ≥2-fold under 50% inhibitory concentration. Our findings provide insight about the detoxification of selenite inE. colivia induction of these genes involved in the selenite reduction process.

scholarly journals Identification and Expression Profiling of Nonphosphorus Glycerolipid Synthase Genes in Response to Abiotic Stresses in Dendrobium catenatum

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1204
Author(s):  
Xinqiao Zhan ◽  
Yichun Qian ◽  
Bizeng Mao
Keyword(s):  
Salt Stress ◽  
Drought Stress ◽  
Expression Profiling ◽  
Abiotic Stresses ◽  
Membrane Lipids ◽  
Chinese Herb ◽  
Growth Stages ◽  
Limited Information ◽  
Gene Structures ◽  
Functional Investigation

Dendrobium catenatum, a valuable Chinese herb, frequently experiences abiotic stresses, such as cold and drought, under natural conditions. Nonphosphorus glycerolipid synthase (NGLS) genes are closely linked to the homeostasis of membrane lipids under abiotic stress in plants. However, there is limited information on NGLS genes in D. catenatum. In this study, a total of eight DcaNGLS genes were identified from the D. catenatum genome; these included three monogalactosyldiacylglycerol synthase (DcaMGD1, 2, 3) genes, two digalactosyldiacylglycerol synthase (DcaDGD1, 2) genes, and three sulfoquinovosyldiacylglycerol synthase (DcaSQD1, 2.1, 2.2) genes. The gene structures and conserved motifs in the DcaNGLSs showed a high conservation during their evolution. Gene expression profiling showed that the DcaNGLSs were highly expressed in specific tissues and during rapid growth stages. Furthermore, most DcaNGLSs were strongly induced by freezing and post-freezing recovery. DcaMGD1 and DcaSQDs were greatly induced by salt stress in leaves, while DcaDGDs were primarily induced by salt stress in roots. Under drought stress, most DcaNGLSs were regulated by circadian rhythms, and DcaSQD2 was closely associated with drought recovery. Transcriptome analysis also revealed that MYB might be regulated by circadian rhythm and co-expressed with DcaNGLSs under drought stress. These results provide insight for the further functional investigation of NGLS and the regulation of nonphosphorus glycerolipid biosynthesis in Dendrobium.

scholarly journals Lipidomics Provides New Insight into Pathogenesis and Therapeutic Targets of the Ischemia—Reperfusion Injury

2021 ◽  
Vol 22 (6) ◽  
pp. 2798
Author(s):  
Zoran Todorović ◽  
Siniša Đurašević ◽  
Maja Stojković ◽  
Ilijana Grigorov ◽  
Slađan Pavlović ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Time Course ◽  
Membrane Lipids ◽  
Lipid Analysis ◽  
Cell Damage ◽  
Ischemia Reperfusion ◽  
Enzyme Inactivation ◽  
Critical Event ◽  
Tissue Ischemia ◽  
Insight Into

Lipids play an essential role in both tissue protection and damage. Tissue ischemia creates anaerobic conditions in which enzyme inactivation occurs, and reperfusion can initiate oxidative stress that leads to harmful changes in membrane lipids, the formation of aldehydes, and chain damage until cell death. The critical event in such a series of harmful events in the cell is the unwanted accumulation of fatty acids that leads to lipotoxicity. Lipid analysis provides additional insight into the pathogenesis of ischemia/reperfusion (I/R) disorders and reveals new targets for drug action. The profile of changes in the composition of fatty acids in the cell, as well as the time course of these changes, indicate both the mechanism of damage and new therapeutic possibilities. A therapeutic approach to reperfusion lipotoxicity involves attenuation of fatty acids overload, i.e., their transport to adipose tissue and/or inhibition of the adverse effects of fatty acids on cell damage and death. The latter option involves using PPAR agonists and drugs that modulate the transport of fatty acids via carnitine into the interior of the mitochondria or the redirection of long-chain fatty acids to peroxisomes.

Reduction of selenate and selenite to elemental selenium by Wolinella succinogenes

1992 ◽  
Vol 38 (12) ◽  
pp. 1328-1333 ◽  
Author(s):  
Francisco A. Tomei ◽  
Larry L. Barton ◽  
Cheryl L. Lemanski ◽  
Thomas G. Zocco
Keyword(s):  
Stationary Growth Phase ◽  
Elemental Selenium ◽  
Bacterial Cells ◽  
Wolinella Succinogenes ◽  
Stationary Growth ◽  
X Ray ◽  
Dense Granules ◽  
Transmission Electron ◽  
Final Electron ◽  
Final Electron Acceptor

Cultures of Wolinella succinogenes were adapted to grow in the presence of 1 mM [Formula: see text] or 10 mM [Formula: see text]. Both selenium salts were reduced to red, amorphous, elemental selenium but only after the culture reached the stationary growth phase. Bacterial cells taken from a culture actively reducing selenium were examined by transmission electron microscopy and were found to have large, electron-dense granules in the cytoplasm. These granules were verified by energy-dispersive X-ray spectroscopy to consist of selenium. Wolinella succinogenes was unable to grow with [Formula: see text] or [Formula: see text] as the final electron acceptor. Key words: Wolinella, selenium, cytology, selenate.

Reduction of Selenite and Detoxification of Elemental Selenium by the Phototrophic BacteriumRhodospirillum rubrum

1999 ◽  
Vol 65 (11) ◽  
pp. 4734-4740 ◽  
Author(s):  
J. Kessi ◽  
M. Ramuz ◽  
E. Wehrli ◽  
M. Spycher ◽  
R. Bachofen
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Density ◽  
Culture Medium ◽  
Rhodospirillum Rubrum ◽  
Buoyant Density ◽  
Elemental Selenium ◽  
Selenite Reduction ◽  
Final Cell Density ◽  
Cell Densities

ABSTRACT The effect of selenite on growth kinetics, the ability of cultures to reduce selenite, and the mechanism of detoxification of selenium were investigated by using Rhodospirillum rubrum. Anoxic photosynthetic cultures were able to completely reduce as much as 1.5 mM selenite, whereas in aerobic cultures a 0.5 mM selenite concentration was only reduced to about 0.375 mM. The presence of selenite in the culture medium strongly affected cell division. In the presence of a selenite concentration of 1.5 mM cultures reached final cell densities that were only about 15% of the control final cell density. The cell density remained nearly constant during the stationary phase for all of the selenite concentrations tested, showing that the cells were not severely damaged by the presence of selenite or elemental selenium. Particles containing elemental selenium were observed in the cytoplasm, which led to an increase in the buoyant density of the cells. Interestingly, the change in the buoyant density was reversed after selenite reduction was complete; the buoyant density of the cells returned to the buoyant density of the control cells. This demonstrated that R. rubrum expels elemental selenium across the plasma membrane and the cell wall. Accordingly, electron-dense particles were more numerous in the cells during the reduction phase than after the reduction phase.

Time course of solute accumulation and water relations in muskmelon plants exposed to salt during different growth stages

Plant Science ◽  
1998 ◽  
Vol 138 (1) ◽  
pp. 103-112 ◽  
Author(s):  
Micaela Carvajal ◽  
Francisco M. del Amor ◽  
Gregorio Fernandez-Ballester ◽  
Vicente Martı́nez ◽  
Antonio Cerdá
Keyword(s):  
Water Relations ◽  
Time Course ◽  
Growth Stages ◽  
Solute Accumulation ◽  
Different Growth Stages

Analysis of the Crushing Effect about Ultrasound on E. coli and B. subtilis

2012 ◽  
Vol 260-261 ◽  
pp. 1017-1021
Author(s):  
Xin Ying Wang ◽  
Yong Tao Liu ◽  
Min Hui ◽  
Ji Fei Xu
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Bacillus Subtilis ◽  
Bacterial Cell ◽  
Logarithmic Phase ◽  
Growth Stages ◽  
Bacterial Cells ◽  
E Coli ◽  
Different Growth Stages ◽  
Main Factor

Escherichia coli and Bacillus subtilis as objects of the study, ultrasonic fragmentation acted on the bacterial cells in different growth stages, results showed that, it’s similar to the crushing effect of ultrasound on E. coli and B. subtilis cells of different growth stages, the highest crushing rate in the logarithmic phase, reached to 95.8% and 94.3% respectively, the crushing rate of adjustment phase is lowest, maintained at around 60%, the crushing rate stability cell was centered, which can be achieved 90%. The structure of the bacterial cell wall didn’t the main factor to decide the ultrasonic fragmentation effect, but different growth periods of bacterial cells did the determinant.

Time Course of SDS–alkaline lysis of recombinant bacterial cells for plasmid release

1998 ◽  
Vol 60 (6) ◽  
pp. 768-770 ◽  
Author(s):  
L. A. S. Ciccolini ◽  
P. Ayazi Shamlou ◽  
N. J. Titchener-Hooker ◽  
J. M. Ward ◽  
P. Dunnill
Keyword(s):  
Time Course ◽  
Bacterial Cells ◽  
Alkaline Lysis

scholarly journals Pyridine-2,6-Bis(Thiocarboxylic Acid) Produced by Pseudomonas stutzeri KC Reduces and Precipitates Selenium and Tellurium Oxyanions

2006 ◽  
Vol 72 (5) ◽  
pp. 3119-3129 ◽  
Author(s):  
Anna M. Zawadzka ◽  
Ronald L. Crawford ◽  
Andrzej J. Paszczynski
Keyword(s):  
Wild Type Strain ◽  
Hydrolysis Product ◽  
Pseudomonas Stutzeri ◽  
Elemental Selenium ◽  
Bacterial Cells ◽  
Wild Type ◽  
Chemical Structures ◽  
Thiocarboxylic Acid ◽  
Insoluble Compounds ◽  
Initial Line

ABSTRACT The siderophore of Pseudomonas stutzeri KC, pyridine-2,6-bis(thiocarboxylic acid) (pdtc), is shown to detoxify selenium and tellurium oxyanions in bacterial cultures. A mechanism for pdtc's detoxification of tellurite and selenite is proposed. The mechanism is based upon determination using mass spectrometry and energy-dispersive X-ray spectrometry of the chemical structures of compounds formed during initial reactions of tellurite and selenite with pdtc. Selenite and tellurite are reduced by pdtc or its hydrolysis product H2S, forming zero-valent pdtc selenides and pdtc tellurides that precipitate from solution. These insoluble compounds then hydrolyze, releasing nanometer-sized particles of elemental selenium or tellurium. Electron microscopy studies showed both extracellular precipitation and internal deposition of these metalloids by bacterial cells. The precipitates formed with synthetic pdtc were similar to those formed in pdtc-producing cultures of P. stutzeri KC. Culture filtrates of P. stutzeri KC containing pdtc were also active in removing selenite and precipitating elemental selenium and tellurium. The pdtc-producing wild-type strain KC conferred higher tolerance against selenite and tellurite toxicity than a pdtc-negative mutant strain, CTN1. These observations support the hypothesis that pdtc not only functions as a siderophore but also is involved in an initial line of defense against toxicity from various metals and metalloids.

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