scholarly journals Transcriptomic Response Analysis of Escherichia coli to Palladium Stress

2021 ◽  
Vol 12 ◽  
Author(s):  
Nadeem Joudeh ◽  
Athanasios Saragliadis ◽  
Christian Schulz ◽  
André Voigt ◽  
Eivind Almaas ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Heavy Metal Stress ◽  
Pd Nanoparticles ◽  
Genetically Engineered ◽  
Response Analysis ◽  
Bacterial Cells ◽  
Transcriptomic Response ◽  
E Coli ◽  
Inorganic Ion ◽  
Wide Range

Palladium (Pd), due to its unique catalytic properties, is an industrially important heavy metal especially in the form of nanoparticles. It has a wide range of applications from automobile catalytic converters to the pharmaceutical production of morphine. Bacteria have been used to biologically produce Pd nanoparticles as a new environmentally friendly alternative to the currently used energy-intensive and toxic physicochemical methods. Heavy metals, including Pd, are toxic to bacterial cells and cause general and oxidative stress that hinders the use of bacteria to produce Pd nanoparticles efficiently. In this study, we show in detail the Pd stress-related effects on E. coli. Pd stress effects were measured as changes in the transcriptome through RNA-Seq after 10 min of exposure to 100 μM sodium tetrachloropalladate (II). We found that 709 out of 3,898 genes were differentially expressed, with 58% of them being up-regulated and 42% of them being down-regulated. Pd was found to induce several common heavy metal stress-related effects but interestingly, Pd causes unique effects too. Our data suggests that Pd disrupts the homeostasis of Fe, Zn, and Cu cellular pools. In addition, the expression of inorganic ion transporters in E. coli was found to be massively modulated due to Pd intoxication, with 17 out of 31 systems being affected. Moreover, the expression of several carbohydrate, amino acid, and nucleotide transport and metabolism genes was vastly changed. These results bring us one step closer to the generation of genetically engineered E. coli strains with enhanced capabilities for Pd nanoparticles synthesis.

scholarly journals Photon-Induced Superior Antibacterial Activity of Palladium-Decorated, Magnetically Separable Fe3O4/Pd/mpg-C3N4 Nanocomposites

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3888 ◽  
Author(s):  
Deepika Thakur ◽  
Qui Thanh Hoai Ta ◽  
Jin-Seo Noh
Keyword(s):  
Antibacterial Activity ◽  
Solution Method ◽  
Pd Nanoparticles ◽  
Bacterial Degradation ◽  
Photoluminescence Intensity ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
E Coli ◽  
Carrier Recombination ◽  
Solar Light Irradiation

Three-component nanocomposites (Fe3O4/Pd/mpg-C3N4) have been systematically synthesized using a three-step solution method for the photocatalytic bacterial decontamination. The mesoporous g-C3N4 nanosheets (mpg-C3N4), which were prepared by the acid treatment, showed a great improvement in photocatalytic performance. The photoluminescence intensity of the mpg-C3N4 nanosheets was disclosed to drop about 60% from the value of normal g-C3N4 nanosheets. Decoration of mpg-C3N4 with palladium (Pd) nanoparticles led to the effective suppression of carrier recombination and the carrier migration to Fe3O4 nanoparticles. It was revealed that the three-component nanocomposites degraded 99.9% of E. coli and 99.8% of S. aureus bacterial strains within 2 h of solar light irradiation at a 100 μg/mL concentration, demonstrating their superb photocatalytic antibacterial activity. In addition, the nanocomposites could be easily separated from the bacterial cells and repeatedly used for photocatalytic bacterial degradation with good recyclability. The strong photon-induced antibacterial activity and good recyclability of the three-component nanocomposites may represent their potential as a promising antibacterial photocatalyst.

scholarly journals Artificial Cell Therapy: New Strategies for the Therapeutic Delivery of Live Bacteria

2005 ◽  
Vol 2005 (1) ◽  
pp. 44-56 ◽  
Author(s):  
Satya Prakash ◽  
Mitchell Lawrence Jones
Keyword(s):  
Oral Delivery ◽  
Therapeutic Potential ◽  
Immobilized Cells ◽  
Genetically Engineered ◽  
Live Cells ◽  
Bacterial Cells ◽  
Artificial Cells ◽  
Artificial Cell ◽  
Wide Range ◽  
Live Bacterial Cells

There has been rapid growth in research regarding the use of live bacterial cells for therapeutic purposes. The recognition that these cells can be genetically engineered to synthesize products that have therapeutic potential has generated considerable interest and excitement among clinicians and health professionals. It is expected that a wide range of disease modifying substrates such as enzymes, hormones, antibodies, vaccines, and other genetic products will be used successfully and will impact upon health care substantially. However, a major limitation in the use of these bacterial cells is the complexity of delivering them to the correct target tissues. Oral delivery of live cells, lyophilized cells, and immobilized cells has been attempted but with limited success. Primarily, this is because bacterial cells are incapable of surviving passage through the gastrointestinal tract. In many occasions, when given orally, these cells have been found to provoke immunogenic responses that are undesirable. Recent studies show that these problems can be overcome by delivering live bacterial cells, such as genetically engineered cells, using artificial cell microcapsules. This review summarizes recent advances in the therapeutic use of live bacterial cells for therapy, discusses the principles of using artificial cells for the oral delivery of bacterial cells, outlines methods for preparing suitable artificial cells for this purpose, addresses potentials and limitations for their application in therapy, and provides insight for the future direction of this emergent and highly prospective technology.

scholarly journals Nanotechnology: A New Approach for Reducing Heavy Metal Toxicity in Plants

2018 ◽  
Vol 4 (01) ◽  
pp. 34-40
Author(s):  
Meetu Gupta ◽  
Seema Sahay
Keyword(s):  
Heavy Metal ◽  
Metal Toxicity ◽  
Heavy Metal Stress ◽  
Systematic Investigation ◽  
Heavy Metal Toxicity ◽  
Plant Responses ◽  
Limited Information ◽  
Nano Technology ◽  
Research Fields ◽  
Wide Range

Nano-technology becomes a key technology of 21st century due to endow with immense and wide range applications in several interdisciplinary research fields. Ample literature is available on the individual effect of nanoparticles (NPs) and plant responses, whereas, they also interact with heavy metals (HMs) present in the environment. To date, very limited information is available on the systematic investigation regarding the probability of plant exposure to NPs under heavy metal stress conditions, particularly in context to the use of engineered NPs (ENPs) for reducing heavy metal toxicity. Furthermore, there is a need to explore the interactive mechanism of NPs-metals (NPs-HMs complex) including their uptake, localization, and fate in plants at physiological and molecular level. In this brief review, an attempt has been made to provide some aspects related to the possible mechanism of ENPs in the alleviation of metal toxicity in plants. Besides, an update on ENPs characterization, synthesis, uptake, and translocation was also discussed. This review will help to understand the nature of NPs-HMs complex and its potential to design innovative technologies over heavy metal free ecosystem development.

scholarly journals Humidity-Dependent Bacterial Cells Functional Morphometry Investigations Using Atomic Force Microscope

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Hike Nikiyan ◽  
Alexey Vasilchenko ◽  
Dmitry Deryabin
Keyword(s):  
Cell Wall ◽  
Relative Humidity ◽  
Morphological Properties ◽  
Wall Structure ◽  
Bacterial Cells ◽  
Wall Roughness ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Wide Range

The effect of a relative humidity (RH) in a range of 93–65% on morphological and elastic properties ofBacillus cereusandEscherichia colicells was evaluated using atomic force microscopy. It is shown that gradual dehumidification of bacteria environment has no significant effect on cell dimensional features and considerably decreases them only at 65% RH. The increasing of the bacteria cell wall roughness and elasticity occurs at the same time. Observed changes indicate that morphological properties ofB. cereusare rather stable in wide range of relative humidity, whereasE. coliare more sensitive to drying, significantly increasing roughness and stiffness parameters at RH 84% RH. It is discussed the dependence of the response features on differences in cell wall structure of gram-positive and gram-negative bacterial cells.

scholarly journals Assessment of Photodynamic Destruction of Escherichia coli O157:H7 and Listeria monocytogenes by Using ATP Bioluminescence

2003 ◽  
Vol 69 (11) ◽  
pp. 6393-6398 ◽  
Author(s):  
N. A. Romanova ◽  
L. Y. Brovko ◽  
L. Moore ◽  
E. Pometun ◽  
A. P. Savitsky ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Yeast Cells ◽  
Bacterial Cells ◽  
E Coli ◽  
Intracellular Atp ◽  
Microdilution Method ◽  
Wide Range ◽  
Atp Bioluminescence ◽  
Time Courses

ABSTRACT Antimicrobial photodynamic therapy was shown to be effective against a wide range of bacterial cells, as well as for fungi, yeasts, and viruses. It was shown previously that photodestruction of yeast cells treated with photosensitizers resulted in cell destruction and leakage of ATP. Three photosensitizers were used in this study: tetra(N-methyl-4-pyridyl)porphine tetratosylate salt (TMPyP), toluidine blue O (TBO), and methylene blue trihydrate (MB). A microdilution method was used to determine MICs of the photosensitizers against both Escherichia coli O157:H7 and Listeria monocytogenes. To evaluate the effects of photodestruction on E. coli and L. monocytogenes cells, a bioluminescence method for detection of ATP leakage and a colony-forming assay were used. All tested photosensitizers were effective for photodynamic destruction of both bacteria. The effectiveness of photosensitizers (in microgram-per-milliliter equivalents) decreased in the order TBO > MB > TMPyP for both organisms. The MICs were two- to fourfold higher for E. coli O157:H7 than for L. monocytogenes. The primary effects of all of the photosensitizers tested on live bacterial cells were a decrease in intracellular ATP and an increase in extracellular ATP, accompanied by elimination of viable cells from the sample. The time courses of photodestruction and intracellular ATP leakage were different for E. coli and L. monocytogenes. These results show that bioluminescent ATP-metry can be used for investigation of the first stages of bacterial photodestruction.

scholarly journals Persister Cells Resuscitate via Ribosome Modification by 23S rRNA Pseudouridine Synthase RluD

2019 ◽  
Author(s):  
Sooyeon Song ◽  
Thomas K. Wood
Keyword(s):  
Escherichia Coli ◽  
Small Rna ◽  
23S Rrna ◽  
Bacterial Cells ◽  
Persister Cells ◽  
E Coli ◽  
Pseudouridine Synthase ◽  
Dormant Cells ◽  
Wide Range ◽  
Persister Cell

ABSTRACTUpon a wide range of stress conditions (e.g., nutrient, antibiotic, oxidative), a subpopulation of bacterial cells known as persisters survive by halting metabolism. These cells resuscitate rapidly to reconstitute infections once the stress is removed and nutrients are provided. However, how these dormant cells resuscitate is not understood well but involves reactivating ribosomes. By screening 10,000 compounds directly for stimulating Escherichia coli persister cell resuscitation, we identified that 2-{[2-(4-bromophenyl)-2-oxoethyl]thio}-3-ethyl-5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidin-4(3H)-one (BPOET) stimulates resuscitation. Critically, by screening 4,267 E. coli proteins, we determined that BPOET activates hibernating ribosomes via 23S rRNA pseudouridine synthase RluD, which increases ribosome activity. Corroborating the increased waking with RluD, production of RluD increased the number of active ribosomes in persister cells. Also, inactivating the small RNA RybB which represses rluD led to faster persister resuscitation. Hence, persister cells resuscitate via activation of RluD.

scholarly journals Rob and MarA alter susceptibility ofEscherichia colito antibiotics in presence of salicylate

2017 ◽  
Author(s):  
Kirti Jain ◽  
Supreet Saini
Keyword(s):  
Antibiotic Resistance ◽  
Transcription Factors ◽  
Lethal Concentration ◽  
Bacterial Cells ◽  
Multiple Antibiotic Resistance ◽  
E Coli ◽  
Physiological Relevance ◽  
Wide Range ◽  
Stress Environments ◽  
Cell Counter

AbstractWhen exposed to stress, bacterial cells launch a diverse response to enhance their chances of survival. This response involves modulation of expression of a large number of proteins which help the cell counter stress. This modulation is facilitated by several transcription factors in bacteria and inE. colithree homologous regulators, MarA, Sox, and Rob are known to launch a coordinated response to combat various stress environments. MarA and SoxS are known to control multiple antibiotic resistance and superoxide regulon respectively. Rob has been observed to control similar downstream targets as MarA and SoxS. However, physiological relevance of Rob in not understood. We show that Rob along with MarA, in presence of inducer salicylate, can help cell survive in presence of lethal concentration of wide range of antibiotics.

scholarly journals The Mode of Action of Cyclic Monoterpenes (−)-Limoneneand (+)-α-Pinene on Bacterial Cells

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 806
Author(s):  
Olga E. Melkina ◽  
Vladimir A. Plyuta ◽  
Inessa A. Khmel ◽  
Gennadii B. Zavilgelsky
Keyword(s):  
Heat Shock ◽  
Biological Activities ◽  
Membrane Damage ◽  
Genetically Engineered ◽  
Bacterial Cells ◽  
Prolonged Incubation ◽  
E Coli ◽  
Volatile Organic ◽  
High Concentrations ◽  
First Time

A broad spectrum of volatile organic compounds’ (VOCs’) biological activities has attracted significant scientific interest, but their mechanisms of action remain little understood. The mechanism of action of two VOCs—the cyclic monoterpenes (−)-limonene and (+)-α-pinene—on bacteria was studied in this work. We used genetically engineered Escherichia coli bioluminescent strains harboring stress-responsive promoters (responsive to oxidative stress, DNA damage, SOS response, protein damage, heatshock, membrane damage) fused to the luxCDABE genes of Photorhabdus luminescens. We showed that (−)-limonene induces the PkatG and PsoxS promoters due to the formation of reactive oxygen species and, as a result, causes damage to DNA (SOSresponse), proteins (heat shock), and membrane (increases its permeability). The experimental data indicate that the action of (−)-limonene at high concentrations and prolonged incubation time makes degrading processes in cells irreversible. The effect of (+)-α-pinene is much weaker: it induces only heat shock in the bacteria. Moreover, we showed for the first time that (−)-limonene completely inhibits the DnaKJE–ClpB bichaperone-dependent refolding of heat-inactivated bacterial luciferase in both E. coli wild type and mutant ΔibpB strains. (+)-α-Pinene partially inhibits refolding only in ΔibpB mutant strain.

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