Impact of Physico-Chemical Properties of Cellulose Nanocrystal/Silver Nanoparticle Hybrid Suspensions on Their Biocidal and Toxicological Effects.

There is a demand for nanoparticles that are environmentally acceptable, but simultaneously efficient and low cost. We prepared silver nanoparticles (AgNPs) grafted on a native bio-based substrate (cellulose nanocrystals, CNCs) with high biocidal activity and no toxicological impact. AgNPs of 10 nm are nucleated on CNCs in aqueous suspension with content from 0.

The Whereabouts of 2D Gels in Quantitative Proteomics.

Two-dimensional gel electrophoresis has been instrumental in the development of proteomics. Although it is no longer the exclusive scheme used for proteomics, its unique features make it a still highly valuable tool, especially when multiple quantitative comparisons of samples must be made, and even for large samples series. However, quantitative proteomics using two-dimensional gels is critically dependent on the performances of the protein detection methods used after the electrophoretic separations.

In Situ Formation of Silver Nanoparticles (Ag-NPs) onto Textile Fibers.

Silver nanoparticles (Ag-NPs) adhered/inserted on textile fibers have an effective antimicrobial role. However, their release due to low adherence and their fate in the natural settings have been questioned in terms of toxicity level. In order to overcome this recurrent problem of adherence, the in situ formation of Ag-NPs in five textile fibers (cotton (untreated and chemically bleached), sheep's wool, polyamide, and polyester) was assessed.

ZnO and TiO2 nanoparticles alter the ability of Bacillus subtilis to fight against a stress.

Due to the physicochemical properties of nanoparticles, the use of nanomaterials increases over time in industrial and medical processes. We herein report the negative impact of nanoparticles, using solid growth conditions mimicking a biofilm, on the ability of Bacillus subtilis to fight against a stress. Bacteria have been exposed to sublethal doses of nanoparticles corresponding to conditions that bacteria may meet in their natural biotopes, the upper layer of soil or the gut microbiome.

What Room for Two-Dimensional Gel-Based Proteomics in a Shotgun Proteomics World?

Two-dimensional gel electrophoresis was instrumental in the birth of proteomics in the late 1980s. However, it is now often considered as an outdated technique for proteomics-a thing of the past. Although this opinion may be true for some biological questions, e.

The poly-gamma-glutamate of Bacillus subtilis interacts specifically with silver nanoparticles.

For many years, silver nanoparticles, as with other antibacterial nanoparticles, have been extensively used in manufactured products. However, their fate in the environment is unclear and raises questions. We studied the fate of silver nanoparticles in the presence of bacteria under growth conditions that are similar to those found naturally in the environment (that is, bacteria in a stationary phase with low nutrient concentrations).

Author Correction: Impact of nanoparticles on the Bacillus subtilis (3610) competence.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Impact of nanoparticles on the Bacillus subtilis (3610) competence.

Due to the physicochemical properties of nanoparticles, the use of nanomaterials increases every year in industrial and medical processes. At the same time, the increasing number of bacteria becoming resistant to many antibiotics, mostly by a horizontal gene transfer process, is a major public health concern. We herein report, for the first time, the role of nanoparticles in the physiological induction of horizontal gene transfer in bacteria.

Impact of a Model Soil Microorganism and of Its Secretome on the Fate of Silver Nanoparticles.

Sulfidation is a key process for silver nanoparticles released from consumer products in the environment. This study focuses on the impact of a model soil microorganism, Bacillus subtilis, on the fate of pristine and already sulfidized Ag-NPs. The nanoparticles were incubated with the initial growth medium, isolated secretome, and living bacteria, and characterized for their size and morphology, agglomeration state, structure, and Ag speciation.

Zinc oxide induces the stringent response and major reorientations in the central metabolism of Bacillus subtilis.

Microorganisms, such as bacteria, are one of the first targets of nanoparticles in the environment. In this study, we tested the effect of two nanoparticles, ZnO and TiO2, with the salt ZnSO4 as the control, on the Gram-positive bacterium Bacillus subtilis by 2D gel electrophoresis-based proteomics. Despite a significant effect on viability (LD50), TiO2 NPs had no detectable effect on the proteomic pattern, while ZnO NPs and ZnSO4 significantly modified B.

Preparing protein extracts for quantitative two-dimensional gel comparison.

This unit describes basic protocols for efficient and reproducible protein solubilization from a variety of biological samples, including cultured animal cells and tissues, plant cells and tissues, bacteria, nuclei, other subcellular organelles, plasma, serum, and other biological fluids. The optimized extraction process is strongly sample dependent and cannot be described for every type of sample. Instead, typical protocols are provided as general guidelines and illustrate good starting points for optimization of sample preparation.

Improved proteomic analysis of nuclear proteins, as exemplified by the comparison of two myeloid cell lines nuclear proteomes.

One of the challenges of the proteomic analysis by 2D-gel is to visualize the low abundance proteins, particularly those localized in the organelles. An additional problem with nuclear proteins lies in their strong interaction with nuclear acids. Several experimental procedures have been tested to increase, in the nuclear extract, the ratio of nuclear proteins compared to contaminant proteins, and also to obtain reproducible conditions compatible with 2D-gel electrophoresis.

Two-dimensional gel electrophoresis in proteomics: a tutorial.

Two-dimensional electrophoresis of proteins has preceded, and accompanied, the birth of proteomics. Although it is no longer the only experimental scheme used in modern proteomics, it still has distinct features and advantages. The purpose of this tutorial paper is to guide the reader through the history of the field, then through the main steps of the process, from sample preparation to in-gel detection of proteins, commenting the constraints and caveats of the technique.

Two-dimensional gel electrophoresis in proteomics: Past, present and future.

Two-dimensional gel electrophoresis has been instrumental in the birth and developments of proteomics, although it is no longer the exclusive separation tool used in the field of proteomics. In this review, a historical perspective is made, starting from the days where two-dimensional gels were used and the word proteomics did not even exist. The events that have led to the birth of proteomics are also recalled, ending with a description of the now well-known limitations of two-dimensional gels in proteomics.

Silver staining of proteins in 2DE gels.

Silver staining detects proteins after electrophoretic separation on polyacrylamide gels. Its main positive features are its excellent sensitivity (in the low nanogram range) and the use of very simple and cheap equipment and chemicals. The sequential phases of silver staining are protein fixation, then sensitization, then silver impregnation, and finally image development.

Power and limitations of electrophoretic separations in proteomics strategies.

Proteomics can be defined as the large-scale analysis of proteins. Due to the complexity of biological systems, it is required to concatenate various separation techniques prior to mass spectrometry. These techniques, dealing with proteins or peptides, can rely on chromatography or electrophoresis.

Fully denaturing two-dimensional electrophoresis of membrane proteins: a critical update.

The quality and ease of proteomics analysis depends on the performance of the analytical tools used, and thus of the performances of the protein separation tools used to deconvolute complex protein samples. Among protein samples, membrane proteins are one of the most difficult sample classes, because of their hydrophobicity and embedment in the lipid bilayers. This review deals with the recent progresses and advances made in the separation of membrane proteins by 2-DE separating only denatured proteins.

Ultrafast coelectrophoretic fluorescent staining of proteins with carbocyanines.

Protein detection on SDS gels or on 2-D gels must combine several features, such as sensitivity, homogeneity from one protein to another, speed, low cost, and user-friendliness. For some applications, it is also interesting to have a nonfixing stain, so that proteins can be mobilized from the gel for further use (electroelution, blotting). We show here that coelectrophoretic staining by fluorophores of the oxacarbocyanine family, and especially diheptyloxacarbocyanine, offers several positive features.

The Crl-RpoS regulon of Escherichia coli.

The RpoS subunit of RNA polymerase controls the expression of numerous genes involved in stationary phase and in response to different stress conditions. The regulatory protein Crl increases the activity of RpoS by direct interaction with the RpoS holoenzyme. To define the extent of the Crl regulon, we used two-dimensional SDS-PAGE to measure the role of Crl in regulating the expression of the Escherichia coliproteome in stationary phase at 30 degrees C.

Mutual regulation of Crl and Fur in Escherichia coli W3110.

The small regulatory protein Crl controls the expression of curli. Recently we have shown that Crl interacts directly with one of the most global regulators of Escherichia coli, the stress-related sigma factor RpoS, suggesting a more global role for Crl. We show here by a proteomics analysis that the expression of at least nine cellular proteins was considerably modified when Crl was overexpressed.

Crl, a low temperature-induced protein in Escherichia coli that binds directly to the stationary phase sigma subunit of RNA polymerase.

The alternative sigma factor sigma(S) (RpoS) of Escherichia coli RNA polymerase regulates the expression of stationary phase and stress-response genes. sigma(S) is also required for the transcription of the cryptic genes csgBA that encode the subunits of the curli proteins. The expression of the csgBA genes is regulated in response to a multitude of physiological signals.