Insights into the persistence and phenotypic effects of the endogenous and cryptic plasmid pMF1 in its host strain Myxococcus fulvus 124B02

2020 ◽  
Vol 96 (3) ◽  
Author(s):  
Xiao-jing Chen ◽  
Zheng Zhang ◽  
Ya-jie Li ◽  
Li Zhuo ◽  
Duo-hong Sheng ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Cells ◽  
Fruiting Bodies ◽  
Long Term Effects ◽  
Laboratory Evolution ◽  
E Coli ◽  
Escherichia Coli Cells ◽  
The Social ◽  
Cryptic Plasmids

ABSTRACT Many endogenous plasmids carry no noticeable benefits for their bacterial hosts, and the persistence of these ‘cryptic plasmids’ and their functional impacts are mostly unclear. In this study, we investigated these uncertainties using the social bacterium Myxococcus fulvus 124B02 and its endogenous plasmid pMF1. pMF1 possesses diverse genes that originated from myxobacteria, suggesting a longstanding co-existence of the plasmid with various myxobacterial species. The curing of pMF1 from 124B02 had almost no phenotypic effects on the host. Laboratory evolution experiments showed that the 124B02 strain retained pMF1 when subcultured on dead Escherichia coli cells but lost pMF1 when subcultured on living E. coli cells or on casitone medium; these results indicated that the persistence of pMF1 in 124B02 was environment-dependent. Curing pMF1 caused the mutant to lose the ability to predate and develop fruiting bodies more quickly than the pMF1-containing strain after they were subcultured on dead E. coli cells, which indicated that the presence of pMF1 in M. fulvus 124B02 has some long-term effects on its host. The results provide some new insights into the persistence and impacts of cryptic plasmids in their natural bacterial cells.

scholarly journals A Role for Single-Stranded Exonucleases in the Use of DNA as a Nutrient

2009 ◽  
Vol 191 (11) ◽  
pp. 3712-3716 ◽  
Author(s):  
Vyacheslav Palchevskiy ◽  
Steven E. Finkel
Keyword(s):  
Escherichia Coli ◽  
Bacterial Cells ◽  
Wild Type ◽  
Nutrient Source ◽  
Term Survival ◽  
Natural Competence ◽  
E Coli ◽  
Double Stranded Dna ◽  
Better Than

ABSTRACT Nutritional competence is the ability of bacterial cells to utilize exogenous double-stranded DNA molecules as a nutrient source. We previously identified several genes in Escherichia coli that are important for this process and proposed a model, based on models of natural competence and transformation in bacteria, where it is assumed that single-stranded DNA (ssDNA) is degraded following entry into the cytoplasm. Since E. coli has several exonucleases, we determined whether they play a role in the long-term survival and the catabolism of DNA as a nutrient. We show here that mutants lacking either ExoI, ExoVII, ExoX, or RecJ are viable during all phases of the bacterial life cycle yet cannot compete with wild-type cells during long-term stationary-phase incubation. We also show that nuclease mutants, alone or in combination, are defective in DNA catabolism, with the exception of the ExoX− single mutant. The ExoX− mutant consumes double-stranded DNA better than wild-type cells, possibly implying the presence of two pathways in E. coli for the processing of ssDNA as it enters the cytoplasm.

scholarly journals RNase E Maintenance of Proper FtsZ/FtsA Ratio Required for Nonfilamentous Growth of Escherichia coli Cells but Not for Colony-Forming Ability

2006 ◽  
Vol 188 (14) ◽  
pp. 5145-5152 ◽  
Author(s):  
Masaru Tamura ◽  
Kangseok Lee ◽  
Christine A. Miller ◽  
Christopher J. Moore ◽  
Yukio Shirako ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Liquid Culture ◽  
Bacterial Cells ◽  
Rnase E ◽  
Null Mutant ◽  
E Coli ◽  
Escherichia Coli Cells ◽  
Solid Media ◽  
Rnase G

ABSTRACT Inactivation or deletion of the RNase E-encoding rne gene of Escherichia coli results in the growth of bacterial cells as filamentous chains in liquid culture (K. Goldblum and D. Apirion, J. Bacteriol. 146:128-132, 1981) and the loss of colony-forming ability (CFA) on solid media. RNase E dysfunction is also associated with abnormal processing of ftsQAZ transcripts (K. Cam, G. Rome, H. M. Krisch, and J.-P. Bouché, Nucleic Acids Res. 24:3065-3070, 1996), which encode proteins having a central role in septum formation during cell division. We show here that RNase E regulates the relative abundances of FtsZ and FtsA proteins and that RNase E depletion results in decreased FtsZ, increased FtsA, and consequently an altered FtsZ/FtsA ratio. However, while restoration of the level of FtsZ to normal in rne null mutant bacteria reverses the filamentation phenotype, it does not restore CFA. Conversely, overexpression of a related RNase, RNase G, in rne-deleted bacteria restores CFA, as previously reported, without affecting FtsZ abundance. Our results demonstrate that RNase E activity is required to maintain a proper cellular ratio of the FtsZ and FtsA proteins in E. coli but that FtsZ deficiency does not account for the nonviability of cells lacking RNase E.

scholarly journals Enhanced Production of δ-Guaiene, a Bicyclic Sesquiterpene Accumulated in Agarwood, by Coexpression of δ-Guaiene Synthase and Farnesyl Diphosphate Synthase Genes in Escherichia coli

2016 ◽  
Vol 11 (9) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Takahiro Kato ◽  
Jung-Bum Lee ◽  
Futoshi Taura ◽  
Fumiya Kurosaki
Keyword(s):  
Escherichia Coli ◽  
Recombinant Protein ◽  
Immunoblot Analysis ◽  
Farnesyl Diphosphate ◽  
Farnesyl Diphosphate Synthase ◽  
Transformed Cells ◽  
Bacterial Cells ◽  
E Coli ◽  
Enhanced Production ◽  
Escherichia Coli Cells

Two genes involved in δ-guaiene biosynthesis in Aquilaria microcarpa, δ-guaiene synthase (GS) and farnesyl diphosphate synthase (FPS), were overexpressed in Escherichia coli cells. Immunoblot analysis revealed that the concentration of GS-translated protein was rather low in the cells transformed by solely GS while appreciable accumulation of the recombinant protein was observed when GS was coexpressed with FPS GS-transformed cells liberated only a trace amount of δ-guaiene (0.004 μg/mL culture), however, the concentration of the compound elevated to 0.08 μg/mL culture in the cells transformed by GS plus FPS δ-Guaiene biosynthesis was markedly activated when E. coli cells coexpressing GS and FPS were incubated in enriched Terrific broth, and the content of the compound increased to approximately 0.6 μg/mL culture. These results suggest that coexpression of FPS and GS in E. coli is required for efficient 6-guaiene production in the bacterial cells, and the sesquiterpene-producing activity of the transformant is appreciably enhanced in the nutrients-enriched medium.

Assessment of correlation between physiological states of Escherichia coli cells and their susceptibility to chlorine using flow cytometry

2013 ◽  
Vol 13 (4) ◽  
pp. 1056-1062 ◽  
Author(s):  
Saeid Rezaeinejad ◽  
Volodymyr Ivanov
Keyword(s):  
Escherichia Coli ◽  
Flow Cytometry ◽  
Growth Rates ◽  
Specific Growth ◽  
Bacterial Cells ◽  
Tetrazolium Chloride ◽  
E Coli ◽  
Escherichia Coli Cells ◽  
Cell Subpopulations ◽  
Specific Growth Rates

The physiological differences of individual cells of bacterial population may imply the existence of cell subpopulations with different sensitivity to chlorine, which may affect the efficiency of drinking water disinfection. The susceptibility of individual bacterial cells to chlorine was examined using flow cytometry. The inactivation of Escherichia coli cells by chlorine in the populations with specific growth rates of 0.2 and 0.9 h−1 was assessed using various viability indicators. Viability of bacterial cells was evaluated using membrane integrity propidium iodide (PI) dye, respiratory activity indicator of 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) and membrane potential probe of DiBAC4(3). It was found that there were cell subpopulations of E. coli with different levels of susceptibility to chlorine. E. coli cell population with higher specific growth rate was more susceptible to chlorine. The CT values for inactivation of 99% of cells (CT99) in populations of E. coli with specific growth rates of 0.9 and 0.2 h−1 were 0.06 and 0.09 mg min l−1, respectively. Flow cytometry could be used to study the sensitivity of bacterial cells to the chemical agents.

scholarly journals Stability of plasmid pBR322 within Escherichia coli cells

2021 ◽  
Vol 6 (1) ◽  
pp. 17-19
Author(s):  
Tahsin Tabassum ◽  
Tasmin Tabassum ◽  
Nafisa Tabassum ◽  
Syeda Muntaka Maniha ◽  
Rashed Noor
Keyword(s):  
Escherichia Coli ◽  
Drug Resistance ◽  
Heat Shock ◽  
Plasmid Stability ◽  
Bacterial Cells ◽  
Plasmid Pbr322 ◽  
E Coli ◽  
Replica Plating ◽  
Escherichia Coli Cells ◽  
Pbr322 Plasmid

nsertion of plasmids into the bacterial cells is of great significance especially in course of the transfer of drug resistance, virulence and other traits. Retention of plasmids within the host bacteria is therefore an important factor for bacterial homeostasis. Current study inferred the pBR322 plasmid stability within the Escherichia coli competent cells. The calcium chloride heat shock method was used for the transformation purpose. The plasmid retention phenomenon was assessed through the replica plating. The results positively showed the plasmid retention within E. coli.

Exogenous Histidine as a Co-factor which Exacerbates the Toxicity of Hydrogen Peroxide in Cultured Mammalian and Bacterial Cells

1991 ◽  
Vol 19 (1) ◽  
pp. 68-70
Author(s):  
Giorgio Brandi ◽  
Piero Sestili ◽  
Andrea Guidarelli ◽  
Giuditta Fiorella Schiavano ◽  
Amedeo Albano ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Mammalian Cells ◽  
Culture Medium ◽  
Chinese Hamster ◽  
Bacterial Cells ◽  
E Coli ◽  
Escherichia Coli Cells ◽  
Casamino Acids

The killing of Escherichia coli cells by H2O2 is higher when exposure to the oxidant is performed in a complete culture medium, as compared to saline. Whereas MgSO4, CaCl2, thiamine or glucose, added separately or in combination with the saline, had no effect on the cytotoxic response to H2O2, the cytotoxicity appeared highly dependent upon the presence of the casamino acids in the incubation medium. One of these amino acids, histidine, was found to greatly augment the toxicity of H2O2 in E. coli. This effect of histidine was also observed in mammalian cells. In fact, both the cytoxicity and the DNA damage produced by H2O2 in Chinese hamster ovary (CHO) cells were significantly increased by this amino acid.

East Germany

2017 ◽  
Author(s):  
Detlef Pollack ◽  
Gergely Rosta
Keyword(s):  
Structural Transformation ◽  
East Germany ◽  
External Factors ◽  
The Political ◽  
Long Term Effects ◽  
State Security ◽  
Security Service ◽  
The Social ◽  
The Church

The case of East Germany raises the question of why religion and church, which had fallen to an unprecedentedly low level after four decades of suppression, have not recovered since 1989. The repressive church politics of the SED were undoubtedly the decisive factor in the unique process of minoritizing churches in the GDR. However, other external factors such as increasing prosperity, socio-structural transformation, and the expansion of the leisure and entertainment sector played an important role, too. In addition, church activity itself probably also helped to weaken the social position of churches. The absence of a church renaissance after 1990 can be explained by several factors, such as the long-term effects of the break with tradition caused by the GDR system, the political and moral discrediting of the church by the state security service, and people’s dwindling confidence in the church, which was suddenly seen as a non-representative Western institution.

scholarly journals Long-term effects of the proline-rich antimicrobial peptide Oncocin112 on the Escherichia coli translation machinery

2020 ◽  
Vol 295 (38) ◽  
pp. 13314-13325
Author(s):  
Yanyu Zhu ◽  
James C. Weisshaar ◽  
Mainak Mustafi
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Peptides ◽  
Binding Site ◽  
Elongation Factor ◽  
Microscopy Study ◽  
Single Step ◽  
Long Term Effects ◽  
Bacterial Membranes

Proline-rich antimicrobial peptides (PrAMPs) are cationic antimicrobial peptides unusual for their ability to penetrate bacterial membranes and kill cells without causing membrane permeabilization. Structural studies show that many such PrAMPs bind deep in the peptide exit channel of the ribosome, near the peptidyl transfer center. Biochemical studies of the particular synthetic PrAMP oncocin112 (Onc112) suggest that on reaching the cytoplasm, the peptide occupies its binding site prior to the transition from initiation to the elongation phase of translation, thus blocking further initiation events. We present a superresolution fluorescence microscopy study of the long-term effects of Onc112 on ribosome, elongation factor-Tu (EF-Tu), and DNA spatial distributions and diffusive properties in intact Escherichia coli cells. The new data corroborate earlier mechanistic inferences from studies in vitro. Comparisons with the diffusive behavior induced by the ribosome-binding antibiotics chloramphenicol and kasugamycin show how the specific location of each agent's ribosomal binding site affects the long-term distribution of ribosomal species between 30S and 50S subunits versus 70S polysomes. Analysis of the single-step displacements from ribosome and EF-Tu diffusive trajectories before and after Onc112 treatment suggests that the act of codon testing of noncognate ternary complexes (TCs) at the ribosomal A-site enhances the dissociation rate of such TCs from their L7/L12 tethers. Testing and rejection of noncognate TCs on a sub-ms timescale is essential to enable incorporation of the rare cognate amino acids into the growing peptide chain at a rate of ∼20 aa/s.

scholarly journals Protein Aggregation in E. coli : Short Term and Long Term Effects of Nutrient Density

PLoS ONE ◽  
2014 ◽  
Vol 9 (9) ◽  
pp. e107445 ◽  
Author(s):  
Ulfat I. Baig ◽  
Bharati J. Bhadbhade ◽  
Dincy Mariyam ◽  
Milind G. Watve
Keyword(s):  
Protein Aggregation ◽  
Long Term Effects ◽  
Short Term ◽  
E Coli ◽  
Nutrient Density

scholarly journals Crisis and Continuation: The Digital Relocation of Jain Socio-Religious Praxis during the COVID-19 Pandemic

Religions ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 342
Author(s):  
Tine Vekemans
Keyword(s):  
Digital Media ◽  
Long Term Effects ◽  
Religious Activities ◽  
Face To Face ◽  
The Social ◽  
Religious Praxis ◽  
Online Format ◽  
Media Channels ◽  
Selection Of

In early 2020, Jain diaspora communities and organizations that had been painstakingly built over the past decades were faced with the far-reaching consequences of the COVID-19 pandemic and its concomitant restrictions. With the possibility of regular face-to-face contact and participation in recurring events—praying, eating, learning, and meditating together—severely limited in most places, organizations were compelled to make a choice. They either had to suspend their activities, leaving members to organize their religious activities on an individual or household basis, or pursue the continuation of some of their habitual activities in an online format, relying on their members’ motivation and technical skills. This study will explore how many Jain organizations in London took to digital media in its different forms to continue to engage with their members throughout 2020. Looking at a selection of websites and social media channels, it will examine online discourses that reveal the social and mental impact of the pandemic on Jains and the broader community, explore the relocation of activities to the digital realm, and assess participation in these activities. In doing so, this article will open a discussion on the long-term effects of this crisis-induced digital turn in Jain religious praxis, and in socio-cultural life in general.

Sign in / Sign up

Export Citation Format

Share Document