Deciphering the mechanisms involved in reduced sensitivity to azoles and fengycin lipopeptide in Venturia inaequalis.

Apple scab, caused by the hemibiotrophic fungus Venturia inaequalis, is currently the most common and damaging disease in apple orchards. Two strains of V. inaequalis (S755 and Rs552) with different sensitivities to azole fungicides and the bacterial metabolite fengycin were compared to determine the mechanisms responsible for these differences.

Bacillus velezensis BE2 controls wheat and barley diseases by direct antagonism and induced systemic resistance.

Wheat and barley rank among the main crops cultivated on a global scale, providing the essential nutritional foundation for both humans and animals. Nevertheless, these crops are vulnerable to several fungal diseases, such as Septoria tritici blotch and net blotch, which significantly reduce yields by adversely affecting leaves and grain quality. To mitigate the effect of these diseases, chemical fungicides have proven to be genuinely effective; however, they impose a serious environmental burden.

Norine: Bioinformatics Methods and Tools for the Characterization of Newly Discovered Nonribosomal Peptides.

In this chapter, we present Norine ( https://norine.univ-lille.fr/norine ), the unique resource dedicated to nonribosomal peptides.

The Diversity of Lipopeptides in the Pseudomonas syringae Complex Parallels Phylogeny and Sheds Light on Structural Diversification during Evolutionary History.

Pseudomonas spp. colonize diverse aquatic and terrestrial habitats and produce a wide variety of secondary metabolites, including lipopeptides. However, previous studies have often examined a limited number of lipopeptide-producing strains.

The absence of PNPase activity in Enterococcus faecalis results in alterations of the bacterial cell-wall but induces high proteolytic and adhesion activities.

Enterococci are lactic acid bacteria (LAB) used as starters and probiotics, delineating their positive attributes. Nevertheless, enterococci can be culprit for thousands of infectious diseases, including urinary tract infections, bacteremia and endocarditis. Here, we aim to determine the impact of polynucleotide phosphorylase (PNPase) in the biology of Enterococcus faecalis 14; a human isolate from meconium.

Nonribosomal Peptide Synthesis Definitely Working Out of the Rules.

Nonribosomal peptides are microbial secondary metabolites exhibiting a tremendous structural diversity and a broad range of biological activities useful in the medical and agro-ecological fields. They are built up by huge multimodular enzymes called nonribosomal peptide synthetases. These synthetases are organized in modules constituted of adenylation, thiolation, and condensation core domains.

Screening of Antimicrobial Activities and Lipopeptide Production of Endophytic Bacteria Isolated from Vetiver Roots.

The exploration of certain microbial resources such as beneficial endophytic microorganisms is considered a promising strategy for the discovery of new antimicrobial compounds for the pharmaceutical industries and agriculture. Thirty-one endophytic bacterial strains affiliated with , , , , , and were previously isolated from vetiver (  (L.) Roberty) roots.

Dataset on phenotypic characterization, on protein and genome analysis of three fluorescent strains from mid-mountain water.

The identification of non-fermentative Gram negative bacilli from run-off and spring water, including fluorescent is very complex and investigations are needed to contribute to the systematic of these bacteria. In this dataset, the phenotypical profiles of three strains isolated from Vosges mountains first identified as were determined using API 50 CH galleries. Then, the identification of their proteins released directly into water was carried out using tandem/mass spectrometry after separating proteins on native two-dimensional polyacrylamide gels.

Fluorescent Pseudomonas strains from mid-mountain water able to release antioxidant proteins directly into water.

Little is known about fluorescent Pseudomonas and investigations are needed to help us better understand how their species work. The aim was here to mimic what naturally occurs in environmental water containing strains isolated from mid-mountain water samples and identified as Pseudomonas fluorescens by conventional biochemical techniques. Three strains were cultured before being directly inoculated into distilled water.

sp. COW3 Produces New Bananamide-Type Cyclic Lipopeptides with Antimicrobial Activity against and .

species are metabolically robust, with capacity to produce secondary metabolites including cyclic lipopeptides (CLPs). Herein we conducted a chemical analysis of a crude CLP extract from the cocoyam rhizosphere-derived biocontrol strain sp. COW3.

Draft Genome Sequence of DD14, a Bacteriocinogenic Lactic Acid Bacterium with Anti- Activity.

We report the draft genome sequence of DD14, a strain isolated from meconium of a healthy newborn at Roubaix Hospital (France). The strain displayed antagonism against a set of Gram-positive bacteria through concomitant production of lactic acid and bacteriocin. The genome has a size of 2,893,365 bp and a 37.

Structural and functional analysis of betaine aldehyde dehydrogenase from Staphylococcus aureus.

When exposed to high osmolarity, methicillin-resistant Staphylococcus aureus (MRSA) restores its growth and establishes a new steady state by accumulating the osmoprotectant metabolite betaine. Effective osmoregulation has also been implicated in the acquirement of a profound antibiotic resistance by MRSA. Betaine can be obtained from the bacterial habitat or produced intracellularly from choline via the toxic betaine aldehyde (BA) employing the choline dehydrogenase and betaine aldehyde dehydrogenase (BADH) enzymes.

Adherence to Bürgi-Dunitz stereochemical principles requires significant structural rearrangements in Schiff-base formation: insights from transaldolase complexes.

The Bürgi-Dunitz angle (αBD) describes the trajectory of approach of a nucleophile to an electrophile. The adoption of a stereoelectronically favorable αBD can necessitate significant reactive-group repositioning over the course of bond formation. In the context of enzyme catalysis, interactions with the protein constrain substrate rotation, which could necessitate structural transformations during bond formation.

LigSearch: a knowledge-based web server to identify likely ligands for a protein target.

Identifying which ligands might bind to a protein before crystallization trials could provide a significant saving in time and resources. LigSearch, a web server aimed at predicting ligands that might bind to and stabilize a given protein, has been developed. Using a protein sequence and/or structure, the system searches against a variety of databases, combining available knowledge, and provides a clustered and ranked output of possible ligands.

Verapamil block of T-type calcium channels.

Verapamil is a prototypical phenylalkylamine (PAA), and it was the first calcium channel blocker to be used clinically. It tonically blocks L-type channels in the inner pore with micromolar affinity, and its affinity increases at depolarized membrane potentials. In T-type calcium channels, verapamil blocks with micromolar affinity and has modestly increased affinity at depolarized potentials.

Insights into the mechanism of type I dehydroquinate dehydratases from structures of reaction intermediates.

The biosynthetic shikimate pathway consists of seven enzymes that catalyze sequential reactions to generate chorismate, a critical branch point in the synthesis of the aromatic amino acids. The third enzyme in the pathway, dehydroquinate dehydratase (DHQD), catalyzes the dehydration of 3-dehydroquinate to 3-dehydroshikimate. We present three crystal structures of the type I DHQD from the intestinal pathogens Clostridium difficile and Salmonella enterica.

Activation of membrane cholesterol by 63 amphipaths.

A few membrane-intercalating amphipaths have been observed to stimulate the interaction of cholesterol with cholesterol oxidase, saponin and cyclodextrin, presumably by displacing cholesterol laterally from its phospholipid complexes. We now report that this effect, referred to as cholesterol activation, occurs with dozens of other amphipaths, including alkanols, saturated and cis- and trans-unsaturated fatty acids, fatty acid methyl esters, sphingosine derivatives, terpenes, alkyl ethers, ketones, aromatics and cyclic alkyl derivatives. The apparent potency of the agents tested ranged from 3 microM to 7 mM and generally paralleled their octanol/water partition coefficients, except that relative potency declined for compounds with >10 carbons.

High-dispersion spherical holographic gratings in a modified rowland mounting.

For holographic gratings requiring an extreme dispersion, I consider a modified Rowland mounting, in which the recording laser sources are moved away from the grating, to reduce the uncorrected higher-order aberrations. In addition, I choose the geometric parameters such that first-type coma is corrected. Then a plane multimode deformable mirror (MDM) or two auxiliary spherical holographic gratings (R3 device) are used to aberrate the grating's recording sources; correction up to the fourth order is sufficient to obtain high image quality.

Universal method for holographic grating recording: multimode deformable mirrors generating Clebsch-Zernike polynomials.

Recording methods for making aberration-corrected holographic gratings are greatly simplified by use of a plane multimode deformable mirror (MDM) upon one of the two recording beams. It is shown that MDM compensators easily provide the superposition of many interesting active optics modes, which we have named Clebsch-Zernike modes. When we apply only a uniform loading or no loading at all onto the rear side of the MDM clear aperture, the available Clebsch-Zernike modes are made to belong to a subclass of the Zernike modes that includes the three modes of the third-order aberration theory as well as a well-defined part of the Zernike higher-order modes.

Recording high-dispersion spherical holographic gratings in a modified Rowland mounting by use of a multimode deformable mirror.

To reduce the uncorrected higher-order aberrations for holographic gratings requiring an extreme dispersion, we have modified the Rowland mounting by moving the recording laser sources away from the grating. Then, with a multimode deformable plane mirror to record the grating, the correction of all the aberrations up to the fourth order inclusive is found sufficient to obtain a high-quality image. Applied to the FUSE-LYMAN grating, with a groove density of as much as 5740 grooves/mm, for which a resolution of 30,000 was required, this new recording device produces a resolution from 139,000 to 222,000 over the spectral range.

Third-generation holographic Rowland mounting: fourth-order theory.

The third-generation holographic Rowland mount consists of a Rowland-mounted, optimally recorded holographic spherical grating, referred to as an optimized Rowland grating (ORG), whose recording sources are aberrated by two auxiliary ORG's. The main purpose of this mount is to avoid any aspherical surface while providing control over all the parameters needed to correct the aberrations up to and including the fourth order. Earlier [Appl.

Theory and computation of three cosmic origin spectrograph aspheric gratings recorded with a multimode deformable mirror.

The theory of three Cosmic Origin Spectrograph holographic gratings recorded with a deformable plane mirror is presented. Their working conditions are severe, since they have to correct the strong spherical aberration and the field astigmatism of the Hubble Space Telescope. Recorded on aspherized substrates, the gratings produce images that are diffraction limited with regard to spectral resolution.

Illustration of the use of multimode deformable plane mirrors to record high-resolution concave gratings: results for the Cosmic Origins Spectrograph gratings of the Hubble Space Telescope.

To illustrate the efficiency of using a deformable plane mirror to record holographic gratings, we have computed the three gratings for the Cosmic Origins Spectrograph. Their working conditions are severe, since they have to correct the residual spherical aberration of the Hubble Space Telescope. Nevertheless, all images obtained are largely diffraction limited with regard to the resolution.

Theory of spherical holographic gratings recorded by use of a multimode deformable mirror.

We present the theory of spherical holographic gratings recorded by use of a deformable plane mirror and consider its application to the optimized Rowland Mounting. We illustrate the efficiency of such a mounting by computing two high-resolution gratings (3800 grooves/mm) with f/24 and f/10 apertures.