0000000000095473
AUTHOR
Christophe Sandt
Protection of yeast cells in micro-organized shells of natural polyelectrolytes during drying process
The encapsulation techniques are applied in various fields and for various applications. The layer-by-layer self-assembly (LbL), one of the encapsulation techniques, is built by the electrostatic attraction between oppositely charged polyelectrolytes, and the topmost layer determines essentially the sur-face properties of the edifice. This technique offers several advantages (low cost, simplicity of process and equipment, biocompatibility and biodegra-dation, etc.). In this present paper, results of the protection of Saccharomyces cerevisiae yeast cells in microorganized shell of natural polyelectrolytes during dehydration process are reported. To apply the LbL method to individually encaps…
Are bacterial spores activated by High Pressure treatment at 20°C ?
International audience
Techniques to Analyze sRNA Protein Cofactor Self-Assembly In Vitro
Post-transcriptional control of gene expression by small regulatory noncoding RNA (sRNA) needs protein accomplices to occur. Past research mainly focused on the RNA chaperone Hfq as cofactor. Nevertheless, recent studies indicated that other proteins might be involved in sRNA-based regulations. As some of these proteins have been shown to self-assemble, we describe in this chapter protocols to analyze the nano-assemblies formed. Precisely, we focus our analysis on Escherichia coli Hfq as a model, but the protocols presented here can be applied to analyze any polymer of proteins. This chapter thus provides a guideline to develop commonly used approaches to detect prokaryotic protein self-ass…
Understanding the Effects of High Pressure on Bacterial Spores Using Synchrotron Infrared Spectroscopy
International audience; Bacterial spores are extremely resistant life-forms that play an important role in food spoilage and foodborne disease. The return of spores to a vegetative cell state is a three-step process, these being activation, germination, and emergence. High-pressure (HP) processing is known to induce germination in part of the spore population and even to inactivate a high number of Bacillus spores when combined with other mild treatments such as the addition of nisin. The aim of the present work was to investigate the mechanisms involved in the sensitization of spores to nisin following HP treatment at ambient temperature or with moderate heating leading to a heterogeneous …
In Situ Characterization of Hfq Bacterial Amyloid: A Fourier-Transform Infrared Spectroscopy Study
Hfq is a bacterial protein that regulates gene expression at the post-transcriptional level in Gram-negative bacteria. We have previously shown that Escherichia coli Hfq protein, and more precisely its C-terminal region (CTR), self-assembles into an amyloid-like structure in vitro. In the present work, we present evidence that Hfq unambiguously forms amyloid structures also in vivo. Taking into account the role of this protein in bacterial adaptation and virulence, our work opens possibilities to target Hfq amyloid self-assembly and cell location, with potential to block bacterial adaptation and treat infections. Fil: Partouche, David. Centre National de la Recherche Scientifique; Francia. …