Search results for "microbial"

Pulsed electric field and mild heating for milk processing: a review on recent advances.

2019

Pulsed electric field (PEF) treatment consists of exposing food to electrical fields between electrodes within a treatment chamber, which can improve the preservation of fresh-like products such as milk. Although several studies support the use of PEF technology to process milk at low temperature, these studies reported microbial reductions of around 3 log10 cycles and also indicated a limited impact of PEF on some endogenous and microbial enzymes. This scenario indicates that increasing the impact of PEF on both enzymes and microorganisms remains a major challenge for this technology in milk processing. More recently, combining PEF with mild heating (below pasteurization condition) has bee…

A One Health perspective on the issue of the antibiotic resistance

2020

For a few years now, the One Health concept has appeared to go hand in hand with the issue of antibiotic resistance as the most comprehensive and global solution. As part of a study comparing the publicization process of the links between antibiotic resistance and food in France and in the United States, this paper retraces the One Health concept's trajectory in terms of significations and (re)definitions, according to the actors adopting this approach as a viable solution. Furthermore, this paper questions the concept's take over impact in antibiotic resistance reframing as well as its expansion in terms of functioning and applicability. Within social sciences research, interest in the iss…

Stability of Asymmetric Lipid Bilayers Assessed by Molecular Dynamics Simulations

2009

The asymmetric insertion of amphiphiles into biological membranes compromises the balance between the inner and outer monolayers. As a result, area expansion of the receiving leaflet and curvature strain may lead to membrane permeation, shape changes, or membrane fusion events. We have conducted both atomistic and coarse-grained molecular dynamics simulations of dipalmitoyl-phosphatidylcholine (DPPC) bilayers to study the effect of an asymmetric distribution of lipids between the two monolayers on membrane stability. Highly asymmetric lipid bilayers were found to be surprisingly stable within the submicrosecond time span of the simulations. Even the limiting case of a monolayer immersed in …

1,3-Dipolar cycloadditions in the synthesis of annelated diazines: design of new scaffolds for anticancer and antimicrobial agents

2008

Molecular characterization of Treponema pallidum subsp. pallidum in Switzerland and France with a new multilocus sequence typing scheme

2018

Syphilis is an important public health problem and an increasing incidence has been noted in recent years. Characterization of strain diversity through molecular data plays a critical role in the epidemiological understanding of this re-emergence. We here propose a new high-resolution multilocus sequence typing (MLST) scheme for Treponema pallidum subsp. pallidum (TPA). We analyzed 30 complete and draft TPA genomes obtained directly from clinical samples or from rabbit propagated strains to identify suitable typing loci and tested the new scheme on 120 clinical samples collected in Switzerland and France. Our analyses yielded three loci with high discriminatory power: TP0136, TP0548, and TP…

Photochemical mineralization of terrigenous DOC to dissolved inorganic carbon in ocean

2018

When terrigenous dissolved organic carbon (tDOC) rich in chromophoric dissolved organic matter (tCDOM) enters the ocean, solar radiation mineralizes it partially into dissolved inorganic carbon (DIC). This study addresses the amount and the rates of DIC photoproduction from tDOC and the area of ocean required to photomineralize tDOC. We collected water samples from 10 major rivers, mixed them with artificial seawater, and irradiated them with simulated solar radiation to measure DIC photoproduction and the photobleaching of tCDOM. The linear relationship between DIC photoproduction and tCDOM photobleaching was used to estimate the amount of photoproduced DIC from the tCDOM fluxes of the stu…

Mucin induces CRISPR-Cas defense in an opportunistic pathogen

2022

It is unknown what circumstances promote particular bacterial defenses against bacterial viruses (phages). Almeida & Hoikkala et al. show that mucin, derived from mucus, greatly accelerates CRISPR-Cas defenses against phage in an opportunistic pathogen. Parasitism by bacteriophages has led to the evolution of a variety of defense mechanisms in their host bacteria. However, it is unclear what factors lead to specific defenses being deployed upon phage infection. To explore this question, we co-evolved the bacterial fish pathogen Flavobacterium columnare and its virulent phage V156 in presence and absence of a eukaryotic host signal (mucin) for sixteen weeks. The presence of mucin leads to a …

Volatile Components from Aerial parts of Centaurea diffusa and C. micrantha ssp. melanosticta and their biocidal activity on microorganisms affecting…

2018

The chemical composition of the essential oils from aerial parts of two taxa of Centaurea belonging to subgenus Acrolophus, Centaurea diffusa Lam. and C. micrantha Hoff. ssp. melanosticta (Lange) Dostàl, respectively collected in Croatia and Spain, were evaluated by GC and GC-MS. The main components of C. diffusa were hexadecanoic acid (31.1%), (Z,Z)-9,12-octadecadienoic acid (10.7%) and damascenone isomers (6.4%), whereas hexahydrofarnesyl acetone (27.8%), hexadecanoic acid (8.3%) and caryophyllene oxide (6.4%) were the most abundant components of C. micrantha ssp. melanosticta. The oils showed good antibacterial and antifungal activities against some microorganisms that infest historical …

Old sleeping Sicilian beauty: seed germination in the palaeoendemic Petagnaea gussonei (Spreng.) Rauschert (Saniculoideae, Apiaceae).

2015

Petagnaea gussonei (Apiaceae) is a perennial herbaceous species endemic to northeast Sicily (Nebrodi Mountains). It is considered a remnant of the Sicilian Tertiary flora, and is endangered according to the Red List. There is no information in the literature about the germinability of its seeds, even though seed production is know to occur. The aim of this study was to obtain data to better understand seed germination of this species and its biological implications. Thus, several approaches were employed: vitality analyses, gibberellic acid supply, germination and soil microbial flora analyses via end-point and qPCR. The results suggest that seed germination occurs after ca. 1.5 years at a …

Recurrent inoculation: a strategy for a better survival of Pseudomonas fluorescens strain in soil

2022

A growing interest is shown for microbial inoculants as a promising alternative to agrochemicals for sustainable agricultural. However, biotic and abiotic stresses are known to affect their establishment and effectiveness, leading to inconsistent performance in field conditions. At the same time, a poor survival of the strain is often observed, which constitutes a main hamper for bacterial inoculant development. We hypothesize that recurrent inoculations would improve the survival of the strain in soil. For this purpose, we tested different scenarios of inoculation of the plant growth promoting rhizobacteria Pseudomonas fluorescens in soil microcosms: a single inoculation, two inoculations …