Search results for "R1"
showing 10 items of 1016 documents
Applying a New REFINE Approach in Zymomonas mobilis Identifies Novel sRNAs That Confer Improved Stress Tolerance Phenotypes
2020
As global controllers of gene expression, small RNAs represent powerful tools for engineering complex phenotypes. However, a general challenge prevents the more widespread use of sRNA engineering strategies: mechanistic analysis of these regulators in bacteria lags far behind their high-throughput search and discovery. This makes it difficult to understand how to efficiently identify useful sRNAs to engineer a phenotype of interest. To help address this, we developed a forward systems approach to identify naturally occurring sRNAs relevant to a desired phenotype: RNA-seq Examiner for Phenotype-Informed Network Engineering (REFINE). This pipeline uses existing RNA-seq datasets under differen…
Effect of sequential inoculum of beta-glucosidase positive and probiotic strains on brine fermentation to obtain low salt sicilian table olives
2019
In the present study, the β-glucosidase positive strain Lactobacillus plantarum F3. 3 was used as starter during the fermentation of Sicilian table olives (Nocellara Etnea cultivar) at two different salt concentrations (5 and 8%), in order to accelerate the debittering process. The latter was monitored through the increase of hydroxytyrosol compound. In addition, the potential probiotic Lactobacillus paracasei N24 strain was added after 60 days of fermentation. Un-inoculated brine samples at 5 and 8% of salt were used as control. The fermentation was monitored till 120 days through physico-chemical and microbiological analyses. In addition, volatile organic compounds and sensorial analyses …
Substrate pathways and mechanisms of inhibition in the sulfur oxygenase reductase of Acidianus ambivalens
2011
Background: The sulfur oxygenase reductase (SOR) is the initial enzyme of the sulfur oxidation pathway in the thermoacidophilic Archaeon Acidianus ambivalens. The SOR catalyzes an oxygen-dependent sulfur disproportionation to H2S, sulfite and thiosulfate. The spherical, hollow, cytoplasmic enzyme is composed of 24 identical subunits with an active site pocket each comprising a mononuclear non-heme iron site and a cysteine persulfide. Substrate access and product exit occur via apolar chimney-like protrusions at the four-fold symmetry axes, via narrow polar pores at the three-fold symmetry axes and via narrow apolar pores within in each subunit. In order to investigate the function of the po…
Molecular evidence for ongoing complementarity and horizontal gene transfer in endosymbiotic systems of mealybugs
2014
[EN] Intracellular bacterial supply of essential amino acids is common among sap-feeding insects, thus complementing the scarcity of nitrogenous compounds in plant phloem. This is also the role of the two mealybug endosymbiotic systems whose genomes have been sequenced. In the nested endosymbiotic system from Planococcus citri (Pseudococcinae), “Candidatus Tremblaya princeps” and “Candidatus Moranella endobia” cooperate to synthesize essential amino acids, while in Phenacoccus avenae (Phenacoccinae) this function is performed by its single endosymbiont “Candidatus Tremblaya phenacola.” However, little is known regarding the evolution of essential amino acid supplementation strategies in oth…
Fungal-associated NO is involved in the regulation of oxidative stress during rehydration in lichen symbiosis
2010
[EN] Background Reactive oxygen species (ROS) are normally produced in respiratory and photosynthetic electron chains and their production is enhanced during desiccation/rehydration. Nitric oxide (NO) is a ubiquitous and multifaceted molecule involved in cell signaling and abiotic stress. Lichens are poikilohydrous organisms that can survive continuous cycles of desiccation and rehydration. Although the production of ROS and NO was recently demonstrated during lichen rehydration, the functions of these compounds are unknown. The aim of this study was to analyze the role of NO during rehydration of the lichen Ramalina farinacea (L.) Ach., its isolated photobiont partner Trebouxia sp. and Ast…
Dissemination of CTX-M-Producing Escherichia coli in Freshwater Fishes From a French Watershed (Burgundy)
2019
International audience; The burden of extended-spectrum beta-lactamases producing Escherichia coli (ESBL-Ec), has increased over several decades. Freshwater ecosystems are suspected to play an important ecological and evolutionary role in driving the dissemination of antimicrobial resistance. The aim of our study was to decipher the occurrence of ESBL-Ec in a small watershed (Ouche river, Burgundy, France), targeting environmental matrices and fishes. Among cefotaxime resistant E. coli (ctxR Ec) isolates, we detected and characterized 36 ESBL-Ec from water, biofilm and fish guts. ctxR Ec and ESBL-Ec were found in samples from sites near the first small town, located downstream from the wate…
High Prevalence of Human-Associated Escherichia coli in Wetlands Located in Eastern France
2020
International audience; Escherichia coli that are present in the rivers are mostly brought by human and animal feces. Contamination occurs mostly through wastewater treatment plant (WWTP) outflows and field amendment with sewage sludge or manure. However, the survival of these isolates in river-associated wetlands remains unknown. Here, we assessed E. coli population structure in low-anthropized wetlands located along three floodplains to identify the major source of contamination of wetlands, whose functioning is different from the rivers. We retrieved 179 E. coli in water samples collected monthly from 19 sites located in eastern France over 1 year. Phylogroups B1 and B2 were dominant in …
Antimicrobial Resistance and the Spectrum of Pathogens in Dental and Oral-Maxillofacial Infections in Hospitals and Dental Practices in Germany
2021
Data on microbiological profiles in odontogenic infections are scarce. This study aimed to analyze the spectrum of pathogens and antimicrobial resistance in clinical isolates from dental and oral-maxillofacial clinical settings in Germany. We analyzed 20,645 clinical isolates (dental practices: n = 5,733; hospitals: n = 14,912) from patients with odontogenic infections using data (2012–2019) from the German Antimicrobial-Resistance-Surveillance (ARS) system. A total of 224 different species from 73 genera were found in clinical isolates from dental practices, and 329 different species from 97 genera were identified in isolates from hospital patients. In both hospitals and dental practices S…
Occurrence of CTX-M Producing Escherichia coli in Soils, Cattle, and Farm Environment in France (Burgundy Region).
2012
Article en open access; International audience; CTX-M [a major type of extended-spectrum beta-lactamase (ESBU] producing Escherichia coli are increasingly involved in human infections worldwide. The aim of this study was to investigate potential reservoirs for such strains: soils, cattle, and farm environment. The prevalence of bla(CTX-M) genes was determined directly from soil DNA extracts obtained from 120 sites in Burgundy (France) using real-time PCR. bla(CTX-M) targets were found in 20% of the DNA extracts tested. Samples of cattle feces (n = 271) were collected from 182 farms in Burgundy. Thirteen ESBL-producing isolates were obtained from 12 farms and further characterized for the pr…
Cetylpyridinium chloride promotes disaggregation of SARS-CoV-2 virus-like particles
2022
ABSTRACT Background SARS-CoV-2 is continuously disseminating worldwide. The development of strategies to break transmission is mandatory. Aim of the study To investigate the potential of cetylpyridinium chloride (CPC) as a viral inhibitor. Methods SARS-CoV-2 Virus Like-Particles (VLPs) were incubated with CPC, a potent surfactant routinely included in mouthwash preparations. Results Concentrations of 0.05% CPC (w/v) commonly used in mouthwash preparations are sufficient to promote the rupture of SARS-CoV-2 VLP membranes. Conclusion Including CPC in mouthwashes could be a prophylactic strategy to keep SARS-CoV-2 from spreading.