Publications by authors named "Florence Ruaudel"

Article Synopsis
  • The phytopathogenic bacterium Dickeya dadantii uses the type 2 secretion system (T2SS) to release enzymes and factors that degrade plant cell walls and contribute to its virulence.
  • The GspB protein plays a crucial role in assembling the secretin protein GspD, necessary for forming outer membrane pores, and affects the secretion of pectinase, an enzyme involved in plant cell wall degradation.
  • Structural analyses show that GspB interacts with GspD and anchors secretin channels to the inner membrane, while phylogenetic studies reveal variations of GspB in other bacteria, indicating a diverse role in secretion systems.
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The type II secretion system (T2SS) transports fully folded proteins of various functions and structures through the outer membrane of Gram-negative bacteria. The molecular mechanisms of substrate recruitment by T2SS remain elusive but a prevailing view is that the secretion determinants could be of a structural nature. The phytopathogenic γ-proteobacteria, Pectobacterium carotovorum and Dickeya dadantii, secrete similar sets of homologous plant cell wall degrading enzymes, mainly pectinases, by similar T2SSs, called Out.

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Storage conditions of the spawn of edible fungi are of major importance to facilitate the production of mushrooms. Here, standard storage conditions at 10°C or 15°C were used and the potential of colonization of standard European compost by the tropical species Agaricus subrufescens was assessed during the spawn running phase. Two lignocellulolytic activities, laccase and CMC-cellulase, were enhanced after storage compared to control as well as substrate transformation, as described by the aromaticity ratio and a humification ratio calculated from NMR data.

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The potential of Agaricus subrufescens strains to colonize and transform horse manure and wheat-straw-based mushroom compost under the physico-chemical conditions typically used for Agaricus bisporus was assessed. Lignocellulolytic activities, H2O2 production and substrate transformation (assessed via CP/MAS NMR of (13)C) for certain A. subrufescens strains were similar or even greater than those obtained for an A.

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The widespread concern about pollution caused by Polycyclic Aromatic Hydrocarbons (PAHs) raises the question of how they affect soil microbial communities which are potentially involved in the transformation of these pollutants. Using microcosms, we describe the effect of anthracene, a model PAH, on microbial communities inhabiting a Pinus halepensis litter from both coastal (COS) and inland (INL) Mediterranean sites. The microcosms were incubated over 3 months (25°C, 60% WHC) and the effects of anthracene on microbial activities of both litters were monitored.

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The biomass of 18 strains of Agaricus subrufescens and of 13 strains of Agaricus bisporus was chemically analyzed using solid-state (13)C NMR. The study focused on polysaccharides because they can play a major role as antitumor molecules. The study also examined whether biomass chemical properties varied between the vegetative mycelium and the fruiting bodies of A.

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Microbial communities in sewage sludge and green waste co-composting were investigated using culture-dependent methods and community level physiological profiles (CLPP) with Biolog Microplate. Different microbial groups characterized each stage of composting. Bacterial densities were high from beginning to end of composting, whereas actinomycete densities increased only after bio-oxidation phase i.

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