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During biological invasion process, species encounter new environments and partially escape some ecological constraints they faced in their native range, while they face new ones. The Asian tiger mosquito Aedes albopictus is one of the most iconic invasive species introduced in every inhabited continent due to international trade. It has also been shown to be infected by a prevalent yet disregarded microbial entomoparasite Ascogregarina taiwanensis. In this study, we aimed at deciphering the factors that shape the global dynamics of A. taiwanensis infection in natural A. albopictus populations. We showed that A. albopictus populations are highly colonized by several parasite genotypes but recently introduced ones are escaping it. We further performed experiments based on the invasion process to explain such pattern. To that end, we hypothesized that (i) mosquito passive dispersal (i.e. human-aided egg transportation) may affect the parasite infectiveness, (ii) founder effects (i.e. population establishment by a small number of mosquitoes) may influence the parasite dynamics, and (iii) unparasitized mosquitoes are more prompt to found new populations through active flight dispersal. The two first hypotheses were supported as we showed that parasite infection decreases over time when dry eggs are stored and that experimental increase in mosquitoes' density improves the parasite horizontal transmission to larvae. Surprisingly, parasitized mosquitoes tend to be more active than their unparasitized relatives. Finally, this study highlights the importance of global trade as a driver of biological invasion of the most invasive arthropod vector species.
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Recent studies show that mosquito-microbiota interactions affects vector competence and fitness. We investigated if host antibodies modifying microbiota impact mosquito physiology. We focused on three prevalent bacteria (Acinetobacter, Pantoea, and Chryseobacterium), originally isolated from the Asian tiger mosquito Aedes albopictus. Our goal was to assess the impact of host antibodies on mosquito microbiota and life traits. Female mosquitoes were fed with blood from rabbits immunized with each bacterium or a mock vaccine. We compared various factors, including feeding behavior, survival rates, and reproductive success of the mosquitoes. Interestingly, mosquitoes fed with blood from a Chryseobacterium-immunized rabbit showed a significant increase in fecundity and egg-hatching rate. This outcome correlated with a decrease in the abundance of Chryseobacterium within the mosquito microbiota. While no significant changes were observed in the alpha and beta diversity indexes between the groups, our network analyses revealed an important finding. The antimicrobiota vaccines had a considerable impact on the bacterial community assembly. They reduced network robustness, and altered the hierarchical organization of nodes in the networks. Our findings provide the basis for the rational design of antimicrobiota vaccines to reduce mosquito fitness and potentially induce infection-refractory states in the microbiota to block pathogen transmission.
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Aedes , Microbiota , Animais , Feminino , Coelhos , Aedes/microbiologia , Mosquitos Vetores , Fertilidade , Reprodução , BactériasRESUMO
Antisolvent crystallization is commonly used in the formation of heat-sensitive compounds as it is the case for most active pharmaceutical ingredients. Membranes have the ability to control the antisolvent mass transfer to the reaction medium, providing excellent mixing that inhibits the formation of local supersaturations responsible for the undesired properties of the resulting crystals. Still, optimization of the operating conditions is required. This work investigates the impact of solution velocity, the effect of antisolvent composition, the temperature and gravity, using glycine-water-ethanol as a model crystallization system, and polypropylene flat sheet membranes. Results proved that in any condition, membranes were consistent in providing a narrow crystal size distribution (CSD) with coefficient of variation (CV) in the range of 0.5-0.6 as opposed to 0.7 obtained by batch and drop-by-drop crystallization. The prism-like shape of glycine crystals was maintained as well, but slightly altered when operating at a temperature of 35 °C with the appearance of smoother crystal edges. Finally, the mean crystal size was within 23 to 40 µm and did not necessarily follow a clear correlation with the solution velocities or antisolvent composition, but increased with the application of higher temperature or gravity resistance. Besides, the monoclinic form of α-glycine was perfectly maintained in all conditions. The results at each condition correlated directly with the antisolvent transmembrane flux that ranged between 0.0002 and 0.001 kg/m2. s. In conclusion, membrane antisolvent crystallization is a robust solution offering consistent crystal properties under optimal operating conditions.
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Insect sequential development evolves from a simple molt towards complete metamorphosis. Like any multicellular host, insects interact with a complex microbiota. In this review, factors driving the microbiota dynamics were pointed out along their development. Special focus was put on tissue renewal, shift in insect ecology, and microbial interactions. Conversely, how the microbiota modulates its host development through nutrient acquisition, hormonal control, and cellular or tissue differentiation was exemplified. Such modifications might have long-term carry-over effects on insect physiology. Finally, remarkable microbe-driven control of insect behaviors along their life cycle was highlighted. Increasing knowledge of those interactions might offer new insights on how insects respond to their environment as well as perspectives on pest- or vector-control strategies.
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Insetos , Microbiota , AnimaisRESUMO
Metal-organic frameworks (MOFs), a sub-group of porous crystalline materials, have been receiving increasing attention for gas separation and pervaporation because of their high thermal and chemical stability, narrow window sizes, as well as tuneable structural, physical, and chemical properties. In this review, we comprehensively discuss developments in the formation of continuous MOF membranes for gas separation and pervaporation. Additionally, the application performance of continuous MOF membranes in gas separation and pervaporation are analysed. Lastly, some perspectives for the future application of continuous MOF membranes for gas separation and pervaporation are given.
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Insects play many important roles in nature due to their diversity, ecological role, and impact on agriculture or human health. They are directly influenced by environmental changes and in particular anthropic activities that constitute an important driver of change in the environmental characteristics. Insects face numerous anthropogenic stressors and have evolved various detoxication mechanisms to survive and/or resist to these compounds. Recent studies highligted the pressure exerted by xenobiotics on insect life-cycle and the important role of insect-associated bacterial microbiota in the insect responses to environmental changes. Stressor exposure can have various impacts on the composition and structure of insect microbiota that in turn may influence insect biology. Moreover, bacterial communities associated with insects can be directly or indirectly involved in detoxification processes with the selection of certain microorganisms capable of degrading xenobiotics. Further studies are needed to assess the role of insect-associated microbiota as key contributor to the xenobiotic metabolism and thus as a driver for insect adaptation to polluted habitats.
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Microbiota , Xenobióticos , Animais , Efeitos Antropogênicos , Bactérias/metabolismo , Humanos , Insetos/fisiologia , Xenobióticos/metabolismoRESUMO
Fungal dye-decolorizing peroxidases (DyPs) have found applications in the treatment of dye-contaminated industrial wastes or to improve biomass digestibility. Their roles in fungal biology are uncertain, although it has been repeatedly suggested that they could participate in lignin degradation and/or modification. Using a comprehensive set of 162 fully sequenced fungal species, we defined seven distinct fungal DyP clades on basis of a sequence similarity network. Sequences from one of these clades clearly diverged from all others, having on average the lower isoelectric points and hydropathy indices, the highest number of N-glycosylation sites, and N-terminal sequence peptides for secretion. Putative proteins from this clade are absent from brown-rot and ectomycorrhizal species that have lost the capability of degrading lignin enzymatically. They are almost exclusively present in white-rot and other saprotrophic Basidiomycota that digest lignin enzymatically, thus lending support for a specific role of DyPs from this clade in biochemical lignin modification. Additional nearly full-length fungal DyP genes were isolated from the environment by sequence capture by hybridization; they all belonged to the clade of the presumably secreted DyPs and to another related clade. We suggest focusing our attention on the presumably intracellular DyPs from the other clades, which have not been characterized thus far and could represent enzyme proteins with novel catalytic properties. KEY POINTS: ⢠A fungal DyP phylogeny delineates seven main sequence clades. ⢠Putative extracellular DyPs form a single clade of Basidiomycota sequences. ⢠Extracellular DyPs are associated to white-rot fungi.
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Basidiomycota , Peroxidase , Basidiomycota/metabolismo , Corantes/metabolismo , Proteínas Fúngicas/metabolismo , Lignina/metabolismo , Peroxidase/química , Peroxidase/genética , Peroxidases/genética , Peroxidases/metabolismoRESUMO
Microbial fuel cells (MFCs) are a novel technique for converting biodegradable materials into electricity. In this study, the efficiency of mixed crystal (TiO2:ZnO) as a membrane modifier of a low-cost, antifouling and self-cleaning cation exchange membrane for MFCs was studied. The modification was prepared using polydopamine (PDA) as the bio-inspired glue, followed by gravity deposition of a mixture of catalyst nanoparticles (TiO2:ZnO 0.03%, 1:1 ratio) as anti-biofouling agents. The effects of the membrane modification were evaluated in terms of power density, open circuit potential, coulombic efficiency, anti-biofouling properties and also color and COD removal efficiency. The results showed that the use of the PDA-modified membrane and a mixture of catalysts facilitated the transfer of cations released during the oxidation process in the anodic compartment of the MFC, which increased the power generation in the MFC by 2.5 times and 5.7 times the current compared to pristine and PDA pristine membranes, decreased the MFC operating cycle time from 5 to 3 days, doubled the lifetime of the membranes and demonstrated higher COD removal efficiency and color removal. Finally, SEM and AFM analysis showed that the modification significantly minimized surface fouling. The modified membranes in this study proved to be a potential alternative to the expensive membranes currently used in MFCs, furthermore, this modification could be an interesting alternative modification for other potential membranes for use in MFCs, due to the fact that the catalyst activation was only performed with visible light (artificial and solar), which could decrease operating costs.
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Fontes de Energia Bioelétrica , Óxido de Zinco , Eletricidade , Eletrodos , Membranas Artificiais , TitânioRESUMO
With the continuous pressure of water contamination caused by textile industry, loose nanofiltration (LNF) membranes prepared by green materials with an extraordinary water permeability are highly desirable for the recovery and purification of dyes and salts. In this work, low-pressure LNF membranes with ultrahigh permeability were fabricated via one-step interfacial polymerization (IP), in which inexpensive natural carbohydrate-derived sugars with large size and low reactivity were utilized as aqueous monomers to design selective layer. A systematic characterization by chemical analysis and optical microscopy demonstrated that the formed polyester film features not only loosen the structure, but also results in a hydrophilic and negatively charged surface. The optimized sucrose-based membrane (Su0.6/TMC0.1) with an excellent water permeability of 52.4 LMH bar-1 was found to have a high rejection of dyes and a high transmission of salts. In addition, the sugar-based membrane manifested an excellent anti-fouling performance and long-term stability. Furthermore, the non-optimized Gl0.6/TMC0.1 and Ra0.6/TMC0.1 membranes also shown a high water permeability, while maintaining a competitive dye/salt separation performance, which confirmed the universal applicability of the membrane design principle. Therefore, the proposed new strategy for preparing next-generation LNF membranes can contribute towards the textile wastewater treatment.
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Corantes , Purificação da Água , Carboidratos , Membranas Artificiais , PoliésteresRESUMO
Sustainable treatment of the highly saline landfill leachate concentrate for application as green fertilizer calls for effective fractionation of the existing humic substances and inorganic salts; advanced selective nanofiltration membranes are proposed for this. One-step, rapid assembly of a tannic acid-Fe3+ coordination complex is a promising strategy to endow the membranes with an enhanced nanofiltration performance. In this study, a robust and homogeneous tannic acid-Fe3+ coordination complex layer was effectively coated onto the surface of a loose nanofiltration substrate in an extremely short time (15 s). After the coating of the tannic acid-Fe3+ coordination complex layer, the nanofiltration membrane showed a significantly reduced molecule weight cutoff (i.e., reduction from 601 to 279 Da) and thus enhanced selectivity towards humic substances. Specifically, the rejection to humic substances of the coated nanofiltration membrane increased from 95.31±0.54% to 99.32±0.18% with negligible rise in salt rejection, demonstrating an enhanced fractionation efficacy for humic substances and salts. Assisted by a diafiltration operation with the coated nanofiltration membrane, humic substances in the landfill leachate concentrate were effectively purified and extracted with 96.60% recovery. Particularly, the humic substances were linearly enriched by ca. 7.8 folds (i.e., from 1837 to 13970 mg·L-1) with a purity of 98.91% for potential application as liquid fertilizer. The one-step rapid tannic acid-Fe3+ coordination complex coating exhibits an impressive efficacy to engineer advanced nanofiltration membranes that could be applied at a large scale for sustainable resource extraction from landfill leachate concentrate.
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Complexos de Coordenação , Poluentes Químicos da Água , Fracionamento Químico , Substâncias Húmicas , MetaisRESUMO
Following the concept of the holobiont, insect-microbiota interactions play an important role in insect biology. Many examples of host-associated microorganisms have been reported to drastically influence insect biological processes such as development, physiology, nutrition, survival, immunity, or even vector competence. While a huge number of studies on insect-associated microbiota have focused on bacteria, other microbial partners including fungi have been comparatively neglected. Yeasts, which establish mostly commensal or symbiotic relationships with their host, can dominate the mycobiota of certain insects. This review presents key advances and progress in the research field highlighting the diversity of yeast communities associated with insects, as well as their impact on insect life-history traits, immunity, and behavior.
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Mosquitoes are considered one of the most important threats worldwide due to their ability to vector pathogens. They are responsible for the transmission of major pathogens such as malaria, dengue, zika, or chikungunya. Due to the lack of treatments or prophylaxis against many of the transmitted pathogens and an increasing prevalence of mosquito resistance to insecticides and drugs available, alternative strategies are now being explored. Some of these involve the use of microorganisms as promising agent to limit the fitness of mosquitoes, attract or repel them, and decrease the replication and transmission of pathogenic agents. In recent years, the importance of microorganisms colonizing the habitat of mosquitoes has particularly been investigated since they appeared to play major roles in their development and diseases transmission. In this issue, we will synthesize researches investigating how microorganisms present within water habitats may influence breeding site selection and oviposition strategies of gravid mosquito females. We will also highlight the impact of such microbes on the fate of females' progeny during their immature stages with a specific focus on egg hatching, development rate, and larvae or pupae survival.
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Mangrove sediments from New Caledonia were screened for xylanase sequences. One enzyme was selected and characterized both biochemically and for its industrial potential. Using a specific cDNA amplification method coupled with a MiSeq sequencing approach, the diversity of expressed genes encoding GH11 xylanases was investigated beneath Avicenia marina and Rhizophora stylosa trees during the wet and dry seasons and at two different sediment depths. GH11 xylanase diversity varied more according to tree species and season, than with respect to depth. One complete cDNA was selected (OFU29) and expressed in Pichia pastoris. The corresponding enzyme (called Xyn11-29) was biochemically characterized, revealing an optimal activity at 40-50 °C and at a pH of 5.5. Xyn11-29 was stable for 48 h at 35 °C, with a half-life of 1 h at 40 °C and in the pH range of 5.5-6. Xyn11-29 exhibited a high hydrolysis capacity on destarched wheat bran, with 40% and 16% of xylose and arabinose released after 24 h hydrolysis. Its activity on wheat straw was lower, with a release of 2.8% and 6.9% of xylose and arabinose, respectively. As the protein was isolated from mangrove sediments, the effect of sea salt on its activity was studied and discussed.
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Effective extraction of useful resources from high-salinity textile wastewater is a critical pathway for sustainable wastewater management. In this study, an integrated loose nanofiltration-electrodialysis process was explored for simultaneous recovery of dyes, NaCl and pure water from high-salinity textile wastewater, thus closing the material loop and minimizing waste emission. Specifically, a loose nanofiltration membrane (molecular weight cutoff of ~800 Da) was proposed to fractionate the dye and NaCl in the high-salinity textile wastewater. Through a nanofiltration-diafiltration unit, including a pre-concentration stage and a constant-volume diafiltration stage, the dye could be recovered from the high-salinity textile wastewater, being enriched at a factor of ~9.0, i.e., from 2.01 to 17.9 g·L-1 with 98.4% purity. Assisted with the subsequent implementation of electrodialysis, the NaCl concentrate and pure water were effectively reclaimed from the salt-containing permeate coming from the loose nanofiltration-diafiltration. Simultaneously, the produced pure water was further recycled to the nanofiltration-diafiltration unit. This study shows the potential of the integration of loose nanofiltation-diafiltration with electrodialysis for sufficient resource extraction from high-salinity textile wastewater.
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Águas Residuárias , Purificação da Água , Membranas Artificiais , Salinidade , TêxteisRESUMO
The functional diversity of the New Caledonian mangrove sediments was examined, observing the distribution of fungal dye-decolorizing peroxidases (DyPs), together with the complete biochemical characterization of the main DyP. Using a functional metabarcoding approach, the diversity of expressed genes encoding fungal DyPs was investigated in surface and deeper sediments, collected beneath either Avicennia marina or Rhizophora stylosa trees, during either the wet or the dry seasons. The highest DyP diversity was observed in surface sediments beneath the R. stylosa area during the wet season, and one particular operational functional unit (OFU1) was detected as the most abundant DyP isoform. This OFU was found in all sediment samples, representing 51-100% of the total DyP-encoding sequences in 70% of the samples. The complete cDNA sequence corresponding to this abundant DyP (OFU 1) was retrieved by gene capture, cloned, and heterologously expressed in Pichia pastoris. The recombinant enzyme, called DyP1, was purified and characterized, leading to the description of its physical-chemical properties, its ability to oxidize diverse phenolic substrates, and its potential to decolorize textile dyes; DyP1 was more active at low pH, though moderately stable over a wide pH range. The enzyme was very stable at temperatures up to 50 °C, retaining 60% activity after 180 min incubation. Its ability to decolorize industrial dyes was also tested on Reactive Blue 19, Acid Black, Disperse Blue 79, and Reactive Black 5. The effect of hydrogen peroxide and sea salt on DyP1 activity was studied and compared to what is reported for previously characterized enzymes from terrestrial and marine-derived fungi.
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Ionic liquids have attracted the attention of the industry and research community as versatile solvents with unique properties, such as ionic conductivity, low volatility, high solubility of gases and vapors, thermal stability, and the possibility to combine anions and cations to yield an almost endless list of different structures. These features open perspectives for numerous applications, such as the reaction medium for chemical synthesis, electrolytes for batteries, solvent for gas sorption processes, and also membranes for gas separation. In the search for better-performing membrane materials and membranes for gas and vapor separation, ionic liquids have been investigated extensively in the last decade and a half. This review gives a complete overview of the main developments in the field of ionic liquid membranes since their first introduction. It covers all different materials, membrane types, their preparation, pure and mixed gas transport properties, and examples of potential gas separation applications. Special systems will also be discussed, including facilitated transport membranes and mixed matrix membranes. The main strengths and weaknesses of the different membrane types will be discussed, subdividing them into supported ionic liquid membranes (SILMs), poly(ionic liquids) or polymerized ionic liquids (PILs), polymer/ionic liquid blends (physically or chemically cross-linked 'ion-gels'), and PIL/IL blends. Since membrane processes are advancing as an energy-efficient alternative to traditional separation processes, having shown promising results for complex new separation challenges like carbon capture as well, they may be the key to developing a more sustainable future society. In this light, this review presents the state-of-the-art of ionic liquid membranes, to analyze their potential in the gas separation processes of the future.
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Sugar transporters are essential components of carbon metabolism and have been extensively studied to control sugar uptake by yeasts and filamentous fungi used in fermentation processes. Based on published information on characterized fungal sugar porters, we show that this protein family encompasses phylogenetically distinct clades. While several clades encompass transporters that seemingly specialized on specific "sugar-related" molecules (e.g., myo-inositol, charged sugar analogs), others include mostly either mono- or di/oligosaccharide low-specificity transporters. To address the issue of substrate specificity of sugar transporters, that protein primary sequences do not fully reveal, we screened "multi-species" soil eukaryotic cDNA libraries for mannose transporters, a sugar that had never been used to select transporters. We obtained 19 environmental transporters, mostly from Basidiomycota and Ascomycota. Among them, one belonged to the unusual "Fucose H+ Symporter" family, which is only known in Fungi for a rhamnose transporter in Aspergillus niger. Functional analysis of the 19 transporters by expression in yeast and for two of them in Xenopus laevis oocytes for electrophysiological measurements indicated that most of them showed a preference for D-mannose over other tested D-C6 (glucose, fructose, galactose) or D-C5 (xylose) sugars. For the several glucose and fructose-negative transporters, growth of the corresponding recombinant yeast strains was prevented on mannose in the presence of one of these sugars that may act by competition for the binding site. Our results highlight the potential of environmental genomics to figure out the functional diversity of key fungal protein families and that can be explored in a context of biotechnology. KEY POINTS: ⢠Most fungal sugar transporters accept several sugars as substrates. ⢠Transporters, belonging to 2 protein families, were isolated from soil cDNA libraries. ⢠Environmental transporters featured novel substrate specificities.
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Metagenômica , Monossacarídeos , Transporte Biológico , Glucose , Proteínas de Membrana Transportadoras/genética , FilogeniaRESUMO
The ever increasing industrial production of commodity and specialty chemicals inexorably depletes the finite primary fossil resources available on Earth. The forecast of population growth over the next 3 decades is a very strong incentive for the identification of alternative primary resources other than petro-based ones. In contrast with fossil resources, renewable biomass is a virtually inexhaustible reservoir of chemical building blocks. Shifting the current industrial paradigm from almost exclusively petro-based resources to alternative bio-based raw materials requires more than vibrant political messages; it requires a profound revision of the concepts and technologies on which industrial chemical processes rely. Only a small fraction of molecules extracted from biomass bears significant chemical and commercial potentials to be considered as ubiquitous chemical platforms upon which a new, bio-based industry can thrive. Owing to its inherent assets in terms of unique process experience, scalability, and reduced environmental footprint, flow chemistry arguably has a major role to play in this context. This review covers a selection of C2 to C6 bio-based chemical platforms with existing commercial markets including polyols (ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,4-butanediol, xylitol, and sorbitol), furanoids (furfural and 5-hydroxymethylfurfural) and carboxylic acids (lactic acid, succinic acid, fumaric acid, malic acid, itaconic acid, and levulinic acid). The aim of this review is to illustrate the various aspects of upgrading bio-based platform molecules toward commodity or specialty chemicals using new process concepts that fall under the umbrella of continuous flow technology and that could change the future perspectives of biorefineries.
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Álcoois/química , Biomassa , Ácidos Carboxílicos/química , Indústria Química/métodos , Furanos/química , Polímeros/química , Álcoois Açúcares/químicaRESUMO
The growing expansion of mosquito vectors leads to the emergence of vector-borne diseases in new geographic areas and causes major public health concerns. In the absence of effective preventive treatments against most pathogens transmitted, vector control remains one of the most suitable strategies to prevent mosquito-borne diseases. Insecticide overuse raises mosquito resistance and deleterious impacts on the environment and non-target species. Growing knowledge of mosquito biology has allowed the development of alternative control methods. Following the concept of holobiont, mosquito-microbiota interactions play an important role in mosquito biology. Associated microbiota is known to influence many aspects of mosquito biology such as development, survival, immunity or even vector competence. Mosquito-associated microbiota is composed of bacteria, fungi, protists, viruses and nematodes. While an increasing number of studies have focused on bacteria, other microbial partners like fungi have been largely neglected despite their huge diversity. A better knowledge of mosquito-mycobiota interactions offers new opportunities to develop innovative mosquito control strategies. Here, we review the recent advances concerning the impact of mosquito-associated fungi, and particularly nonpathogenic fungi, on life-history traits (development, survival, reproduction), vector competence and behavior of mosquitoes by focusing on Culex, Aedes and Anopheles species.
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Polymer-based CO2 selective membranes offer an energy efficient method to separate CO2 from flue gas. `Top-down' polyelectrolytes represent a particularly interesting class of polymer materials based on their vast synthetic flexibility, tuneable interaction with gas molecules, ease of processability into thin films, and commercial availability of precursors. Recent developments in their synthesis and processing are reviewed herein. The four main groups of post-synthetically modified polyelectrolytes discern ionised neutral polymers, cation and anion functionalised polymers, and methacrylate-derived polyelectrolytes. These polyelectrolytes differentiate according to the origin and chemical structure of the precursor polymer. Polyelectrolytes are mostly processed into thin-film composite (TFC) membranes using physical and chemical layer deposition techniques such as solvent-casting, Langmuir-Blodgett, Layer-by-Layer, and chemical grafting. While solvent-casting allows manufacturing commercially competitive TFC membranes, other methods should still mature to become cost-efficient for large-scale application. Many post-synthetically modified polyelectrolytes exhibit outstanding selectivity for CO2 and some overcome the Robeson plot for CO2/N2 separation. However, their CO2 permeance remain low with only grafted and solvent-casted films being able to approach the industrially relevant performance parameters. The development of polyelectrolyte-based membranes for CO2 separation should direct further efforts at promoting the CO2 transport rates while maintaining high selectivities with additional emphasis on environmentally sourced precursor polymers.