Search results for "OSA"
showing 10 items of 9388 documents
Bioplastic recovery from wastewater: A new protocol for polyhydroxyalkanoates (PHA) extraction from mixed microbial cultures
2019
Abstract A new protocol for polyhydroxyalkanoates (PHA) extraction from mixed microbial cultures (MMCs) is proposed. PHA-accumulating capacity of the MMC was selected in a sequencing batch reactor (SBR) fed with a synthetic effluent emulating a fermented oil mill wastewater (OMW). The highest recovery yield and purity (74 ± 8% and 100 ± 5%, respectively) was obtained when using NH4-Laurate for which operating conditions of the extraction process such as temperature, concentration and contact time were optimized. Best conditions for PHA extraction from MMC turned to be: i) a pre-treatment with NaClO at 85 °C with 1 h of contact time, followed by ii) a treatment with lauric acid in a ratio ac…
Invasion of Eragrostis albensis in Central Europe: distribution patterns, taxonomy and phylogenetic insight into the Eragrostis pilosa complex
2021
AbstractThe Eragrostis pilosa complex (Poaceae) comprises five widely distributed and regionally invasive species—E. albensis, E. amurensis, E. imberbis, E. multicaulis, and E. pilosa, distinguished by tiny and variable morphological characters and with so far unknown phylogenetic relationships. Recently, some doubts have been raised about the status of an invasive glandular morphotype occurring in Central Europe assigned either to E. amurensis or to E. albensis. Here, we addressed this issue by analysing morphology, internal transcribed spacers of nuclear ribosomal DNA, and five inter-simple sequence repeat markers. The genetic evidence supported closer relationship of this glandular morph…
Phylogeography and Molecular Evolution of Potato virus Y
2012
Potato virus Y (PVY) is an important plant pathogen, whose host range includes economically important crops such as potato, tobacco, tomato, and pepper. PVY presents three main strains (PVYO, PVYN and PVYC) and several recombinant forms. PVY has a worldwide distribution, yet the mechanisms that promote and maintain its population structure and genetic diversity are still unclear. In this study, we used a pool of 77 complete PVY genomes from isolates collected worldwide. After removing the effect of recombination in our data set, we used Bayesian techniques to study the influence of geography and host species in both PVY population structure and dynamics. We have also performed selection and…
Lake eutrophication and brownification downgrade availability and transfer of essential fatty acids for human consumption
2016
Article
A preliminary approach for modelling the effects of cropping systems on the dynamics of broomrape ( Phelipanche ramosa) in interaction with the non-p…
2011
International audience; The current decrease in herbicide use may increase and diversify weed flora in crops as well as companion bioagressors spreading via weeds. Among these bioagressors is Phelipanche ramosa (L.) Pomel, a parastic plant which is very harmful on oilseed rape. The objective of the present work was to develop a new model (called PheraSys) of the effects of cropping systems on parasite dynamics, in interaction with non-parasitic weed hosts. The structure of this first model version was based on models developed for other parasitic plants and on FlorSys which quantifies the effects of cropping systems on non-parasitic weed flora. PheraSys was parametrized with preliminary val…
Fragmentation-related patterns of genetic differentiation in pedunculate oak (<i>Quercus robur</i>) at two hierarchical scales
2016
Populations at speciesâ range margins are expected to show lower genetic diversity than populations at the core of the range. Yet, long-lived, widespread tree species are expected to be resistant to genetic impoverishment, thus showing comparatively high genetic diversity within populations and low differentiation among populations. Here, we study the distribution of genetic variation in the pedunculate oak ( L.) at its range margin in Finland at two hierarchical scales using 15 microsatellite loci. At a regional scale, we compared variation within versus among three oak populations. At a landscape scale, we examined genetic structuring within one of these populations, growing on an islan…
Genetic structure and molecular variability of grapevine fanleaf virus in sicily
2021
Grapevine fanleaf virus (GFLV) is one of the main causes of grapevine fanleaf degeneration disease (GFDD) and is present in almost all areas where grapevine is cultivated. In this work, we ascertained the presence and spread of GFLV in different commercial vineyards in four Sicilian provinces (Italy), and its genetic structure and molecular variability were studied. In detail, a total of 617 grapevine samples of 11 autochthonous grapevine cultivars were collected in 20 commercial vineyards. Preliminary screening by serological (DAS-ELISA) and molecular (RT-PCR) analyses for ArMV (arabis mosaic virus) and GFLV detection were conducted. Results obtained showed the absence of ArMV in all the s…
Assessing the influence of the amount of reachable habitat on genetic structure using landscape and genetic graphs.
2021
Genetic structure, i.e. intra-population genetic diversity and inter-population genetic differentiation, is influenced by the amount and spatial configuration of habitat. Measuring the amount of reachable habitat (ARH) makes it possible to describe habitat patterns by considering intra-patch and inter-patch connectivity, dispersal capacities and matrix resistance. Complementary ARH metrics computed under various resistance scenarios are expected to reflect both drift and gene flow influence on genetic structure. Using an empirical genetic dataset concerning the large marsh grasshopper (Stethophyma grossum), we tested whether ARH metrics are good predictors of genetic structure. We further i…
Fine-scale spatial genetic structure and gene dispersal in Silene latifolia
2010
Plants are sessile organisms, often characterized by limited dispersal. Seeds and pollen are the critical stages for gene flow. Here we investigate spatial genetic structure, gene dispersal and the relative contribution of pollen vs seed in the movement of genes in a stable metapopulation of the white campion Silene latifolia within its native range. This short-lived perennial plant is dioecious, has gravity-dispersed seeds and moth-mediated pollination. Direct measures of pollen dispersal suggested that large populations receive more pollen than small isolated populations and that most gene flow occurs within tens of meters. However, these studies were performed in the newly colonized rang…
Fine-scale spatial genetic dynamics over the life cycle of the tropical tree Prunus africana
2014
Studying fine-scale spatial genetic patterns across life stages is a powerful approach to identify ecological processes acting within tree populations. We investigated spatial genetic dynamics across five life stages in the insect-pollinated and vertebrate-dispersed tropical tree Prunus africana in Kakamega Forest, Kenya. Using six highly polymorphic microsatellite loci, we assessed genetic diversity and spatial genetic structure (SGS) from seed rain and seedlings, and different sapling stages to adult trees. We found significant SGS in all stages, potentially caused by limited seed dispersal and high recruitment rates in areas with high light availability. SGS decreased from seed and early…