Search results for "Micro"
showing 10 items of 23412 documents
Carbohydrate dynamics in particle-size fractions of sandy spodosols following forest conversion to maize cropping
2006
International audience; In southwest France, much of the forested land on sandy spodosols has been converted to continuous maize cropping in the last few decades. To evaluate the impacts of this change on soil organic matter properties, we compared total organic C and neutral and amino sugars content in whole soil and particle size separates of two forested, and five related sites that had been either clear-cut for 12 and 18 mo, or cultivated to maize for 4-22yr. Soil carbohydrates accounted for 4-7% of the total organic C across all sites. Soil organic C contents of clear-cut and cultivated sites were only 57-79% of the average value measured in forested sites. Accordingly, carbohydrate co…
The drivers of soil microbial communities structure on forest stands along the altitudinal gradient in western carpathians
2020
Abstract This study examines the effect of the soil physicochemical properties and the vegetation diversity and composition on the soil microorganism community structure on the temperate forest stands along the altitudinal gradient. The studied stands were located at three altitudes (600, 900, and 1200 m a.s.l.) on five separate mountain slopes (treated as independent replicates) in the Western Carpathians Mountains (Poland). The soil physicochemical characteristics varied widely between the stands on these same altitude, and only the organic matter content, water-holding capacity and dissolved organic nitrogen differed significantly between the different altitudes, exhibited highest values…
Bacterial rhamnolipids are novel MAMPs conferring resistance to Botrytis cinerea in grapevine
2009
International audience; Rhamnolipids produced by the bacteria Pseudomonas aeruginosa are known as very efficient biosurfactant molecules. They are used for a wide range of industrial applications, especially in food, cosmetics and pharmaceutical formulations as well as in bioremediation of pollutants. In this paper, the role of rhamnolipids as novel molecules triggering defence responses and protection against the fungus Botrytis cinerea in grapevine is presented. The effect of rhamnolipids was assessed in grapevine using cell suspension cultures and vitro-plantlets. Ca2+ influx, mitogen-activated protein kinase activation and reactive oxygen species production form part of early signalling…
Laurel extracts inhibit quorum sensing, virulence factors and biofilm of foodborne pathogens
2020
Antimicrobial, antibiofilm, anti-Quorum sensing (QS) and virulence factors inhibitory capacity of different polarity Laurus nobilis extracts against several pathogenic microorganisms were studied. Some extracts exhibited antibiotic effect against Staphylococcus aureus multidrug-resistant strains. However, all extracts (100 µg/mL) inhibited to some extent the biofilm of most bacteria tested (until 40% for Gram-negative and 76% for Gram-positive). Hexane (HE) and chloroform extract (CE) were potent inhibitors of S. aureus biofilm and the microscopies further confirmed an important reduction in adherent cells. Polystyrene surfaces coated with these extracts showed a decrease in bacterial adhes…
Cohabitation of tree holes by ants and breeding birds in a temperate deciduous forest
2015
A previously unknown association of ants with birds breeding in tree holes is described. Ants Lasius brunneus Latreille (Hymenoptera: Formicidae) were found in c. 15% of nests of Parus major L. and Poecile palustris L. (Paridae) breeding in tree holes in the primeval deciduous forest located in the Białowieża National Park (Poland). The ants preferably used holes located higher above the ground. As such holes are warmer than the unused holes or other nest sites, it is suggested that the ants cohabit holes utilized by the tits to gain thermal benefits.
New polymorphic microsatellite loci in the house sparrow, Passer domesticus.
2009
3 pages; International audience; We developed 13 new polymorphic microsatellite loci in the house sparrow (Passer domesticus), which exhibited from 2 to 15 alleles. Observed and expected heterozygosities ranged from 0.17 to 0.77 and from 0.35 to 0.85, respectively. We detected no linkage disequilibrium between loci. Allele frequencies supported Hardy–Weinberg equilibrium for 8 loci out of 13 after Bonferroni correction. Combined with loci previously isolated in the house sparrow, these new microsatellite markers provide valuable tools to study population genetics of this species.
First evidence of underwater sounds emitted by the living fossils Lepidurus lubbocki and Triops cancriformis (Branchiopoda: Notostraca)
2021
Sound is the most effective means of communication in marine and freshwater ecosystems. However, no data about acoustic emissions from non-malacostracan crustaceans are currently available, so their ability to produce sounds is unknown. For the first time, this study investigated the sound produced by 2 tadpole shrimp species,Triops cancriformisandLepidurus lubbocki.L. lubbockiindividuals were collected from a natural temporary pond in Sicily (Italy), whereasT. cancriformisindividuals were obtained from eggs contained in sediment from a rock pool in Sardinia (Italy). In the laboratory, experimental tanks with the animals (one species at a time) were acoustically monitored. Both species prod…
Experimental climate warming alters the relationship between fungal root symbiosis and Sphagnum litter phenolics in two peatland microhabitats
2017
International audience; Belowground interactions between plants and microorganisms are involved in numerous ecosystems processes such as carbon and nutrient cycling. Understanding their responses to on-going climate warming is thus of paramount importance to better predict future ecosystem functioning. We hypothesized that climate warming alters the interactions between Sphagnum litter phenolics and the fungal root symbiosis of the Ericale plant Andromeda polifolia in a Jura mountain peatland (France). We initiate a climate warming treatment (+1°C) in April 2008 in two microhabitats (lawns and hummocks). We measured polyphenolic contents, mycorrhizal and dark septate endophyte (DSE) root co…
Chlamyphilone, a Novel Pochonia chlamydosporia Metabolite with Insecticidal Activity
2019
Metabolites from a collection of selected fungal isolates have been screened for insecticidal activity against the aphid Acyrthosiphon pisum. Crude organic extracts of culture filtrates from six fungal isolates (Paecilomyces lilacinus, Pochonia chlamydosporia, Penicillium griseofulvum, Beauveria bassiana, Metarhizium anisopliae and Talaromyces pinophilus) caused mortality of aphids within 72 h after treatment. In this work, bioassay-guided fractionation has been used to characterize the main bioactive metabolites accumulated in fungal extracts. Leucinostatins A, B and D represent the bioactive compounds produced by P. lilacinus. From P. griseofulvum and B. bassiana extracts, griseofulvin an…
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 historica…