Influence of activated carbons on the kinetics and mechanisms of aromatic molecules ozonation

Companies have been looking for new methods for treating toxic or refractory wastewaters; which can mainly be used prior to or after or in connexion with biological treatment processes.This paper compares conventional ozone oxidation with activatedcarbon (AC) promoted ozone oxidation, which helps developing a mechanism involving HOradical dot radical. For a compound which is quite easy to oxidise, like 2,4-dichlorophenol (2,4-DCP) conventional ozonation is efficient enough to remove the initial molecule. The mechanism involved mainly consists of an electrophilic attack on the aromatic ring, which is activated by the donor effect of the –OH group, then followed by a 1,3 dipolar cycloaddition (Criegee mechanism) that leads to aliphatic species, mainly carboxylic acids. Yet, the addition of AC, through the presence of HOradical dot radical, enhances the removal of these species which are more refractory.For a refractory compound like nitrobenzene (NB), with a de-activatedaromatic ring because of the attractive effect of –NO2, conventional ozonation is inefficient. On the contrary, this molecule can be quite easily removed with AC promoted oxidation and it is found that the mechanism (electrophilic attack followed by a 1,3 dipolar cycloaddition) is quite similar to the one corresponding to conventional ozonation, but with less selectivity.For both molecules, a mass balance has established that the by-products accounting for more than 75% of the remaining COD can be quantified. A significant part is composed of carboxylic acids (acetic, oxalic, etc.), which could afterwards be easily removed in an industrial wastewater treatment process followed by a final biological treatment step

Variation et évolution de la composition du venin des guêpes parasitoïdes Psyttalia (Hymenoptera, Braconidae) et Leptopilina (Hymenoptera, Figitidae) : une cause possible d'échec et de succès en lutte biologique ?

Endoparasitoid wasps lay eggs and develop inside arthropod hosts, leading to their death. They have evolved various strategies to ensure parasitism success, notably the injection with the eggs of venom that suppresses the host immunity. Although venom composition has been characterized in a growing number of parasitoid families and recent studies suggest that parasitoid virulence can rapidly evolve, the intraspecific variation of venom and its short-Term evolvability remained to be investigated. This information is however essential for understanding the evolution of parasitoid host range and may have implications in biological control. This thesis allowed to demonstrate the occurrence of inter-Individual variability of venom and to develop a method based on the analysis of electrophoretic 1D profiles and the use of “R” functions allowing statistic comparison of protein quantities from numerous individuals. Then, to study the effect of this variability of the venom composition, experimental evolution studies were performed on Psyttalia lounsburyi and Leptopilina boulardi. Overall, the thesis evidenced that parasitoid venom composition (i) is variable at all studied biological levels (ii) changes rapidly, confirming its high evolvability, and (iii) influences key parameters of the parasitoid biology. This may have important implications in biocontrol and raises the question of the mechanisms sustaining this variability.Les guêpes endoparasitoïdes effectuent leur développement dans un hôte arthropode, entraînant sa mort. Parmi les stratégies assurant leur succès parasitaire, la plus commune est l’injection de venin dans l’hôte lors de l’oviposition, provoquant la suppression de l’immunité de l’hôte. Il est connu que la composition du venin est variable entre espèces et que la virulence des parasitoïdes peut évoluer rapidement. Pourtant la variation intraspécifique de la composition du venin n’a jamais été étudiée alors qu’elle est essentielle pour comprendre l’évolution de la gamme d’hôte des parasitoïdes, un paramètre clé en lutte biologique. Cette thèse a permis de démontrer l’existence d’une variabilité inter-Individuelle du venin, et de développer une méthode basée sur l’analyse de profiles d’électrophorèse 1D à l’aide de fonctions “R” permettant la comparaison statistique de la composition protéique d’un grand nombre d’individus. Des évolutions expérimentales ont ensuite été réalisée sur Psyttalia lounsburyi et Leptopilina boulardi pour étudier les effets de la variabilité du venin lors d’un changement d’environnement brutal. Globalement, cette thèse a mis en évidence que la composition du venin (i) est très variable à tous les niveaux étudiés, (ii) évolue rapidement et (iii) impacte des paramètres clés de la biologie des parasitoïdes. Ceci pourrait avoir d’importantes implications en lutte biologique et pose la question des mécanismes de maintien de la variabilité du venin dans le milieu naturel

Statistical analysis of the individual variability of 1D protein profiles as a tool in ecology: an application to parasitoid venom

International audienceUnderstanding the forces that shape eco-evolutionary patterns often requires linking phenotypes to genotypes, allowing characterization of these patterns at the molecular level. DNA-based markers are less informative in this aim compared to markers associated with gene expression and, more specifically, with protein quantities. The characterization of eco-evolutionary patterns also usually requires the analysis of large sample sizes to accurately estimate interindividual variability. However, the methods used to characterize and compare protein samples are generally expensive and time-consuming, which constrains the size of the produced data sets to few individuals. We present here a method that estimates the interindividual variability of protein quantities based on a global, semi-automatic analysis of 1D electrophoretic profiles, opening the way to rapid analysis and comparison of hundreds of individuals. The main original features of the method are the in silico normalization of sample protein quantities using pictures of electrophoresis gels at different staining levels, as well as a new method of analysis of electrophoretic profiles based on a median profile. We demonstrate that this method can accurately discriminate between species and between geographically distant or close populations, based on interindividual variation in venom protein profiles from three endoparasitoid wasps of two different genera (Psyttalia concolor, Psyttalia lounsburyi and Leptopili-na boulardi). Finally, we discuss the experimental designs that would benefit from the use of this method

Variation in the Venom of Parasitic Wasps, Drift, or Selection? Insights From a Multivariate QST Analysis

Differentiation of traits among populations can evolve by drift when gene flow is low relative to drift or selection when there are different local optima in each population (heterogeneous selection), whereas homogeneous selection tends to prevent evolution of such a differentiation. Analyses of geographical variations in venom composition have been done in several taxa such as wasps, spiders, scorpions, cone snails and snakes, but surprisingly never in parasitoid wasps, although their venom should constrain their ability to succeed on locally available hosts. Such a study is now facilitated by the development of an accurate method (quantitative digital analysis) that allows analyzing the quantitative variation of large sets of proteins from several individuals. This method was used here to analyse the venom-based differentiation of four samples of Leptopilina boulardi and five samples of L. heterotoma from populations along a 300 km long south-north gradient in the Rhône-Saône valley (South-East of France). A major result is that the composition of the venom allows to differentiate the populations studied even when separated by few kilometers. We further analyzed these differentiations on the populations (reared under similar conditions to exclude environmental variance) with a QST analysis which compared the variance of a quantitative trait (Q) among the subpopulations (S) to the total variance (T). We also used random forest clustering analyses to detect the venom components the most likely to be adapted locally. The signature of the natural selection was strong for L. heterotoma and L. boulardi. For the latter, the comparison with the differentiation observed at some neutral markers revealed that differentiation was partly due to some local adaptation. The combination of methods used here appears to be a powerful framework for population proteomics and for the study of eco-evolutionary feedbacks between proteomic level and population and ecosystem levels. This is of interest not only for studying field evolution at an intermediate level between the genome and phenotypes, or for understanding the role of evolution in chemical ecology, but also for more applied issues in biological control

Variation and evolution of venom contents in the parasitoid wasps Psyttalia (Hymenoptera, Braconidae) and Leptopilina (Hymenoptera, Figitidae) : a cause of success and failure in biological control ?

Les guêpes endoparasitoïdes effectuent leur développement dans un hôte arthropode, entraînant sa mort. Parmi les stratégies assurant leur succès parasitaire, la plus commune est l’injection de venin dans l’hôte lors de l’oviposition, provoquant la suppression de l’immunité de l’hôte. Il est connu que la composition du venin est variable entre espèces et que la virulence des parasitoïdes peut évoluer rapidement. Pourtant la variation intraspécifique de la composition du venin n’a jamais été étudiée alors qu’elle est essentielle pour comprendre l’évolution de la gamme d’hôte des parasitoïdes, un paramètre clé en lutte biologique. Cette thèse a permis de démontrer l’existence d’une variabilité inter-Individuelle du venin, et de développer une méthode basée sur l’analyse de profiles d’électrophorèse 1D à l’aide de fonctions “R” permettant la comparaison statistique de la composition protéique d’un grand nombre d’individus. Des évolutions expérimentales ont ensuite été réalisée sur Psyttalia lounsburyi et Leptopilina boulardi pour étudier les effets de la variabilité du venin lors d’un changement d’environnement brutal. Globalement, cette thèse a mis en évidence que la composition du venin (i) est très variable à tous les niveaux étudiés, (ii) évolue rapidement et (iii) impacte des paramètres clés de la biologie des parasitoïdes. Ceci pourrait avoir d’importantes implications en lutte biologique et pose la question des mécanismes de maintien de la variabilité du venin dans le milieu naturel.Endoparasitoid wasps lay eggs and develop inside arthropod hosts, leading to their death. They have evolved various strategies to ensure parasitism success, notably the injection with the eggs of venom that suppresses the host immunity. Although venom composition has been characterized in a growing number of parasitoid families and recent studies suggest that parasitoid virulence can rapidly evolve, the intraspecific variation of venom and its short-Term evolvability remained to be investigated. This information is however essential for understanding the evolution of parasitoid host range and may have implications in biological control. This thesis allowed to demonstrate the occurrence of inter-Individual variability of venom and to develop a method based on the analysis of electrophoretic 1D profiles and the use of “R” functions allowing statistic comparison of protein quantities from numerous individuals. Then, to study the effect of this variability of the venom composition, experimental evolution studies were performed on Psyttalia lounsburyi and Leptopilina boulardi. Overall, the thesis evidenced that parasitoid venom composition (i) is variable at all studied biological levels (ii) changes rapidly, confirming its high evolvability, and (iii) influences key parameters of the parasitoid biology. This may have important implications in biocontrol and raises the question of the mechanisms sustaining this variability

Data used in the paper -Statistical analysis of the individual variability of 1D protein profiles as a tool in ecology-

In this folder, their are the data used in the paper "Statistical analysis of the individual variability of 1D protein profiles as a tool in ecology: an application to parasitoid venom"

Table S4 Data Pea aphid symbionts

Data Pea aphid symbionts survey in Europ

Data from: Rapid evolution of symbiont-mediated resistance compromises biological control of aphids by parasitoids

There is growing interest in biological control as a sustainable and environmentally friendly way to control pest insects. Aphids are among the most detrimental agricultural pests worldwide, and parasitoid wasps are frequently employed for their control. The use of asexual parasitoids may improve the effectiveness of biological control because only females kill hosts and because asexual populations have a higher growth rate than sexuals. However, asexuals may have a reduced capacity to track evolutionary change in their host populations. We used a factorial experiment to compare the ability of sexual and asexual populations of the parasitoid Lysiphlebus fabarum to control caged populations of black bean aphids (Aphis fabae) of high and low clonal diversity. The aphids came from a natural population, and one third of the aphid clones harbored Hamiltonella defensa, a heritable bacterial endosymbiont that increases resistance to parasitoids. We followed aphid and parasitoid population dynamics for three months but found no evidence that the reproductive mode of parasitoids affected their effectiveness as biocontrol agents, independent of host clonal diversity. Parasitoids failed to control aphids in most cases, because their introduction resulted in strong selection for clones protected by H. defensa. The increasingly resistant aphid populations escaped control by parasitoids and we even observed parasitoid extinctions in many cages. The rapid evolution of symbiont-conferred resistance in turn imposed selection on parasitoids. In cages where asexual parasitoids persisted until the end of the experiment, they became dominated by a single genotype able to overcome the protection provided by H. defensa. Thus there was evidence for parasitoid counteradaptation, but it was generally too slow for parasitoids to regain control over aphid populations. It appears that when pest aphids possess defensive symbionts, the presence of parasitoid genotypes able to overcome symbiont-conferred resistance is more important for biocontrol success than their reproductive mode

DRYAD_genotype_frequencies

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