Search

The need of biofuels from biomass, including sustainable aviation fuel, without using agricultural land dedicated to food crops, is in constant demand. Strategies to intensify biomass production using mycorrhizal fungi, biostimulants and their combinations could be solutions for improving the cultivation of lignocellulosic plants but still lack well-established validation on metal-contaminated soils. This study aimed to assess the yield of Miscanthus x giganteus J.M. Greef & Deuter and Cannabis sativa L. grown on a metal-contaminated agricultural soil (11 mg Cd, 536 mg Pb and 955 mg Zn kg -1 ) amended with biostimulants and/or arbuscular mycorrhizal fungi, and the shoot Cd, Pb and Zn uptake. A pot trial was carried out with soil collected from a field near a former Pb/Zn smelter in France and six treatments: control (C), protein hydrolysate (a mixture of peptides and amino acids, PH), humic/fulvic acids (HFA), arbuscular mycorrhizae fungi (AMF), PH combined with AMF (PHxAMF), and HFA combined with AMF (HFAxAMF). Metal concentrations in the soil pore water (SPW), pH and electrical conductivity were measured over time. Miscanthus and hemp shoots were harvested on day 90. Both PH and PHxAMF treatments increased SPW Cd, Pb, and Zn concentrations (e.g. by 26, 1.9, and 22.9 times for miscanthus and 9.7, 4.7, and 19.3 times for hemp in the PH and PHxAMF treatments as compared to the control one, respectively). This led to phytotoxicity and reduced shoot yield for miscanthus. Conversely, HFA and HFAxAMF treatments decreased SPW Cd and Zn concentrations, increasing shoot yields for hemp and miscanthus. Shoot Cd, Pb, and Zn uptakes peaked for PH and PHxAMF hemp plants (in μg plant-1, Cd: 310-334, Pb: 34-38, and Zn: 232-309 for PHxAMF and PH, respectively), while lowest values occurred for PH miscanthus plants mainly due to low shoot yield. Overall, this study suggested that humic/fulvic acids can be an effective biostimulant for increasing shoot biomass production in a metal-contaminated soil. These results warrant further investigations of the HFAxAMF in field trials., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Rock-based materials exposed to outdoor environments are naturally colonised by an array of microorganisms, which can cause dissolution and fracturing of the natural stone. Biocolonisation of monuments and architectures of important cultural heritage therefore represents an expensive and recurring problem for local authorities and private owners alike. In this area, preventive strategies to mitigate biocolonisation are generally preferred to curative approaches, such as mechanical cleaning by brush or high-pressure cleaning, to remove pre-existing patina. The aim of this work was to study the interaction between biocidal polyoxometalate-ionic liquid (POM-IL) coatings and calcareous stones and evaluate the capacity of these coatings to prevent biocolonisation through a series of accelerated ageing studies in climate chambers, carried out in parallel with a two-year period of outdoor exposure in north-eastern France. Our experiments show that POM-IL coatings did not affect water vapour transfer nor significantly alter the total porosity of the calcareous stones. Simulated weathering studies replicating harsh (hot and wet) climatic weather conditions demonstrated that the colour variation of POM-IL-coated stones did not vary significantly with respect to the natural uncoated stones. Accelerated biocolonisation studies performed on the weathered POM-IL-coated stones proved that the coatings were still capable of preventing colonisation by an algal biofilm. However, a combination of colour measurements, chlorophyll fluorescence data, and scanning electron microscopy imaging of stones aged outdoors in northern France for two years showed that coated and uncoated stone samples showed signs of colonisation by fungal mycelium and phototrophs. Altogether, our results demonstrate that POM-ILs are suitable as preventative biocidal coatings for calcareous stones, but the correct concentrations must be chosen to achieve a balance between porosity of the stone, the resulting colour variation and the desired duration of the biocidal effect over longer periods of time, particularly in outdoor environments., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Scott G. Mitchell reports financial support was provided by Ministerio de Ciencia e Innovación Agencia Estatal de Investigación. Isabel Franco Castillo reports financial support was provided by Programa Operativo Aragón de Fondo Social Europeo 2014–2020. Scott G. Mitchell reports financial support was provided by Fondo Social del Gobierno de Aragón. Scott G. Mitchell reports administrative support was provided by Servicio General de Apoyo a la Investigación-SAI. Scott G. Mitchell reports administrative support was provided by Laboratorio de Microscopías Avanzadas at University of Zaragoza. Scott G. Mitchell reports administrative support was provided by Interdisciplinary Thematic Platform from CSIC Open Heritage Research and Society (PTI-PAIS)., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Environmental particles have dramatic consequences for health, especially for the most vulnerable people, such as asthmatics. To better understand the impact on gene expression modulation of fine particles (PM2.5-0.3) from different emission sources, a 3D-airway model, a human bronchial epithelium (MucilAir-HF™) reconstructed from primary cells from healthy (EpiH) or asthmatic (EpiA) donors, was used. Repeated air-liquid exposures were performed, and epithelia were sacrificed to extract RNAs and assess gene expression. Data were analyzed according to the emission sources, physiological status, and exposure doses using a recent model consisting in a graph analysis on pairwise expression ratio. The results were compared with those from the classical ΔΔCt method. The graph analysis method proved to have better statistical properties than the classical ΔΔCt method and demonstrated that repeated PM2.5-0.3 exposures induced a dose-dependent up-regulation of the metabolic gene (CYP1B1) and a down-regulation of the inflammation gene (CXCL10). These modulations were greater for "industrial" than for "urban traffic" fine particles, and the effects were found to be greater after exposure of EpiA than EpiH, thus emphasizing the importance of the epithelium's physiological status in sensitivity to particles. Our study is original in terms of the experimental conditions and the graphical statistical analysis model established. The results highlight the importance of particle chemistry on the modulation of cellular and molecular responses, which may vary according to the individual's vulnerability., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The aim of this work was to study the relationship between oxidative stress damages and particulate matter (PM) chemical composition, sources, and PM fractions. PM 2.5-0.3 (PM with equivalent aerodynamic diameter between 2.5 and 0.3 μm) were collected at urban, road traffic and industrial sites in the North of France, and were characterized for major and minor chemical species. Four different fractions (whole PM 2.5-0.3 , organic, water-soluble and non-extractable matter) were considered for each of the PM 2.5-0.3 samples from the three sites. After exposure of BEAS-2B cells to the four different fractions, oxidative stress was studied in cells by quantifying reactive oxygen species (ROS) accumulation, oxidative damage to proteins (carbonylated proteins), membrane alteration (8-isoprostane) and DNA damages (8-OHdG). Whole PM 2.5-0.3 was capable of inducing ROS overproduction and caused damage to proteins at higher levels than other fractions. Stronger cell membrane and DNA damages were found associated with PM and organic fractions from the urban site. ROS overproduction was correlated with level of expression of carbonylated proteins, DNA damages and membrane alteration markers. The PM 2.5-0.3 collected under industrial influence appears to be the less linked to cell damages and ROS production in comparison with the other influences., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

In the context of novel environmental and energy regulations in construction (RE2020), biocomposites derived from bamboo fibers, bamboo powders, and biodegradable poly(lactic)acid polymer, all of which are renewable resources, have been investigated to meet the criteria of the novel regulations. In this work, the biocomposites were manufactured by twin-screw internal mixing at 170 °C for 5 min with a rotation speed of 60 rpm. The composites sheets were then shaped on a hydraulic press at 185 °C. Pore characterization including pore volume fraction, 3D-pore structure and morphology, and pore distribution of these materials were investigated using X-ray tomography combined with image processing (Avizo). The results show that when the bamboo fibers content is increased, an augmentation in the pore volume fraction and the number of large-volume pores could be observed. In turn, the bamboo powder-containing sheet had a significant increase in pore volume fraction, while a higher quantity of smaller pores, with uniform size, could be observed. The water absorption capacity of these composite increases with the increase of the amount of pore distribution, pore connection, and pore volume fraction. In addition, the orientation of the fibers in 3D observation, flexural mechanical properties, and thermal stability of the biocomposites are also reported in this study., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The de-methylesterification of the pectic polysaccharide homogalacturonan (HG) by pectin methylesterases (PMEs) is a critical step in the control of plant cell expansion and morphogenesis. Plants have large gene families encoding PMEs but also PME inhibitors (PMEIs) with differ in their biochemical properties. The Arabidopsis thaliana PECTIN METHYLESTERASE INHIBITOR 3 (PMEI3) gene is frequently used as a tool to manipulate pectin methylesterase activity in studies assessing its role in the control of morphogenesis. One limitation of these studies is that the exact biochemical activity of this protein has not yet been determined. In this manuscript we produced the protein in Pichia pastoris and characterized its activity in vitro . Like other PMEIs, PMEI3 inhibits PME activity at acidic pH in a variety of cell wall extracts and in purified PME preparations, but does not affect the much stronger PME activity at neutral pH. The protein is remarkable heat stable and shows higher activity against PME3 than against PME2, illustrating how different members of the large PMEI family can differ in their specificities towards PME targets. Finally, growing Arabidopsis thaliana seedlings in the presence of purified PMEI3 caused a dose-dependent inhibition of root growth associated with the overall inhibition of HG de-methylesterification of the root surface. This suggests an essential in vivo role for PME activity at acidic pH in HG de-methylesterification and growth control. These results show that purified recombinant PMEI3 is a powerful tool to study the connection between pectin de-methylesterification and cell expansion., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors. Published by Elsevier B.V.)

Pyrotechnic smokes are widely used in civilian and military applications. The major issue arise from the release of particles after smoke combustion but the health risks related to their exposure are poorly documented whereas toxicity of airborne particles on the respiratory target are very well known. Therefore, this study aimed to explore the in vitro toxicity of the particle fraction of different pyrotechnic smokes. Particles from a red signalling smoke (RSS), an hexachloroethane-based obscuring smoke (HC-OS) and an anti-intrusion smoke (AIS) were collected from the cloud. RSS particles displayed the highest organic fraction (quinones and polycyclic aromatic hydrocarbons) of the three samples characterized. AIS particles contained K and cholesterol derivatives. HC-OS particles were mainly metallic with very high concentrations of Al, Fe and Ca. Intrinsic oxidative potential of smoke particles was measured with two assays. Depletions of DTT by RSS particles was greater than depletion obtained with AIS and HC-OS particles but depletion of acid ascorbic (AA) was only observed with HC-OS particles. In vitro toxicity was assessed by exposing human small airway epithelial cells (SAEC) to various concentrations of particles. After 24 h of exposure, cell viability was not affected but significant modifications of mRNA expression of antioxidant (SOD-1 and -2, catalase, HO-1, NQO-1) and inflammatory markers (IL-6, IL-8, TNF-α) were observed and were dependent on smoke type. Particles rich in metal, such as HC-OS, induced a greatest depletion of AA and a greatest inflammatory response, whereas particles rich in organic compounds, such as RSS, induced a greatest DTT depletion and a greatest antioxidant response. In conclusion, the three smoke particles have an intrinsic oxidative potential and triggered a cell adaptive response. Our study improved the knowledge of particle toxicity of pyrotechnic smokes and scientific approach developed here could be used to study other type of particles., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Organic acids commonly have quite symmetrical chromatography profiles at low pH (< 1.5) with strong anionic resins, but a significant tailing can be observed with succinic and citric acids. Classical adsorption models, like the Langmuir model, fail to predict this behavior, which can have a major influence on mean retention times and profile shapes, therefore on chromatography performances. A new retention model was developed to better predict organic acid separation with strong anionic resin. This model combines a refined Langmuir adsorption model and an ion-exchange model. Organic acid adsorption is assumed to be due to hydrogen bonding with sulfate and hydrogen sulfate counter-anions on the resin. The adsorption capacity depends mostly on molecular size: up to sixteen formic acid molecules could be adsorbed per counter-anions, meanwhile only two succinic acid or one citric acid molecules could be adsorbed. This adsorption model was then embedded in a generic and accurate modeling approach (continuous column with mass balance equations solved by the conservation element/solution element (CE/SE) method). All parameters of this column model were identified by fitting the simulation to experimental results (equilibrium curves and pulse tests). Then, the column model was validated with original experimental results from a binary mixture pulse test (formic and succinic acids). Results show that simulations are much more predictive for multi-component pulse tests, both in terms of profile shape and retention time, which cannot be captured without considering ion-exchange., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Within the framework of biocontrol development, several natural lipopeptides produced by Bacillus subtilis show well-documented anti-microbial properties, especially in orchards. However, the number of studies on their putative insecticidal effects remain low despite the growing interest to develop new strategies of orchards pests' control. The rosy apple aphid Dysaphis plantaginea is the major aphid pest causing great leaf damage to apple trees. In this study, we submitted young adult aphids to topical application of three different families of lipopeptides, Plipastatin (Fengycin), Mycosubtilin (Iturin), and Surfactin, either separately or as a ternary mixture. Their aphicidal effects were investigated at 1, 2.5 and 5 g/L, both at 1 h and 24 h after exposure, and their effects on aphid behavior were studied at the 2.5 g/L concentration at 24 h after exposure. When delivered alone, lipopeptides displayed contrasted effects varying from no aphicidal activity for Mycosubtilin to a mortality induced even at low concentrations by Surfactin. Surprisingly, locomotor activity of the surviving aphids was only affected by the two least lethal treatments, Mycosubtilin and the ternary mix. Their feeding behavior was only impacted by Surfactin, the most lethal treatment, that unexpectedly increased phloem sap ingestion. The results are discussed in the context of lipopeptides applicability for integrated pest management., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Due to the presence of trace element (TE) in agricultural soils, wide areas are unproper for food production and the clean-up of soil is not a feasible option. Considering the potential remediation options, the use of aromatic plants producing a high quantity of biomass and developing high-added value sectors such as essential oil (EO) production could be valuable regarding one of the phytomanagement objectives, i.e. the restoration of an economic activity. The purpose of this study was hence to evaluate in situ the suitability of two aromatic crops, clary sage and coriander, for the phytomanagement of aged TE-polluted soils, taking into account plants' growth, development and biomass production, essential oil (EO) content and quality as well as a techno-economic feasibility analysis of the channel. In situ experiments have been carried out on two agricultural plots of 1.5 ha, a TE-polluted one (Pb: 394 ppm - Zn: 443 ppm - Cd: 7.2 ppm) and an unpolluted one (Pb: 22 ppm - Zn: 48 ppm - Cd: 0.4 ppm). Our findings have shown the ability of coriander and sage to grow similarly on both unpolluted and TE-polluted soil and to produce significant amounts of biomass. The pesticide residue and TE analyses have demonstrated that the EO only contained trace amounts of the contaminants, below or close to the limit of quantification of the method used and similar to marketed products. Mycorrhizal inoculation has also shown promising results by increasing the colonization rates of both aromatic plants, but did not result in higher biomass or EO amounts. Our study brings new evidence towards the potential of clary sage to be used for the phytomanagement of TE-polluted areas, given its perennial vegetation cover, tolerance to TE and obtained EO yields., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Hydrophobic organic soil contaminants such as polycyclic aromatic hydrocarbons (PAH) are poorly mobile in the aqueous phase and tend to sorb to the soil matrix, resulting in low bioavailability. Some filamentous fungi are efficient in degrading this kind of pollutants. However, the mechanism of mobilization of hydrophobic compounds by non-motile microorganisms such as filamentous fungi needs investigations to improve pollutant bioavailability and bioremediation efficiency. Usual homogeneous media for microbial growth in the lab are poorly suited to model the soil, which is a compartmentalized and heterogeneous habitat. A microfluidic device was designed to implement a compartmentalization of the fungal inoculum and the source of the pollutant benzo[a]pyrene (BaP) as a deposit of solid crystals in order to gain a further insight into the mechanisms involved in the access to the contaminant and its uptake in soils. Thus in this device, two chambers are connected by an array of parallel microchannels that are wide enough to allow individual hyphae to grow through them. Macro-cultures of Talaromyces helicus in direct contact with BaP have shown its uptake and intracellular storage in lipid bodies despite the low propensity of BaP to cross aqueous phases as shown by simulation. Observations of T. helicus in the microfluidic device through laser scanning confocal microscopy indicate preferential uptake of BaP at a close range and through contact with the cell wall. However faint staining of some hyphae before contact with the deposit also suggests an extracellular transport phenomenon. Macro-culture filtrates analyses have shown that T. helicus releases extracellular non-lipidic surface-active compounds able to lower the surface tension of culture filtrates to 49.4 mN/m. Thus, these results highlight the significance of active mechanisms to reach hydrophobic contaminants before their uptake by filamentous fungi in compartmentalized micro-environments and the potential to improve them through biostimulation approaches for soil mycoremediation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Cancer stem cells (CSCs) with their self-renewal ability are accepted as cells which initiate tumors. CSCs are regarded as interesting targets for novel anticancer therapeutic agents because of their association with tumor recurrence and resistance to conventional therapies, including radiotherapy and chemotherapy. Chimeric antigen receptor (CAR)-T cells are engineered T cells which express an artificial receptor specific for tumor associated antigens (TAAs) by which they accurately target and kill cancer cells. In recent years, CAR-T cell therapy has shown more efficiency in cancer treatment, particularly regarding blood cancers. The expression of specific markers such as TAAs on CSCs in varied cancer types makes them as potent tools for CAR-T cell therapy. Here we review the CSC markers that have been previously targeted with CAR-T cells, as well as the CSC markers that may be used as possible targets for CAR-T cell therapy in the future. Furthermore, we will detail the most important obstacles against CAR-T cell therapy and suggest solutions., Competing Interests: Authors declare that there are no potential conflicts of interest., (© 2021 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V.)

The skin is an essential barrier, protecting the body against the environment and its numerous pollutants. Several environmental pollutants are known to affect the skin, inducing premature aging through mechanisms including oxidative stress, inflammation, and impairment of skin functions. Even climate conditions can impact the skin. Therefore, using a Reconstructed Human Epidermis (RHE), we tested the effect of two samples of fine particulate matters (PM 0.3-2.5 - one metals-rich sample and the other organic compounds-rich), two Volatile Organic Compounds mixtures (VOCs - from a solvent-based paint and a water-based paint) and Tobacco Smoke (TS). All pollutants affected cellular functionality, but to a lesser extent for the water-based paint VOC. This effect was enhanced when RHE were preconditioned for 2 h by a semi-dry airflow (45% relative humidity) before pollutants application, compared to preconditioning by a humid airflow (90% relative humidity). In the absence of preconditioning, IL-1α, IL-6, IL-8, and RANTES were almost systematically induced by pollutants. When RHE were preconditioned by a semi-dry or humid airflow before being subjected to pollutants, the increase of IL-1α, IL-8, and RANTES falls into two groups. Similarly to RHE not treated with pollutants, RHE treated with VOCs after preconditioning by a semi-dry airflow showed increased IL-1α, IL-8, and RANTES release. On the contrary, RHE treated with PM or TS after preconditioning by a semi-dry airflow show a lower increase in IL-1α, IL-8, and RANTES compared to preconditioning by a humid airflow. The effect of real environmental relative humidity conditions of the air, combined with acute exposure to various environmental pollutants, seemed to relate mainly to structural changes of the skin, determining the outcome of the inflammatory response depending on the physicochemical characteristics of pollutants., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Pectin, the major non-cellulosic component of primary cell wall can be degraded by polygalacturonases (PGs) and pectin methylesterases (PMEs) during pathogen attack on plants. We characterized two novel enzymes, VdPG2 and VdPME1, from the fungal plant pathogen Verticillium dahliae. VdPME1 was most active on citrus methylesterified pectin (55-70%) at pH 6 and a temperature of 40 °C, while VdPG2 was most active on polygalacturonic acid at pH 5 and a temperature of 50 °C. Using LC-MS/MS oligoprofiling, and various pectins, the mode of action of VdPME1 and VdPG2 were determined. VdPME1 was shown to be processive, in accordance with the electrostatic potential of the enzyme. VdPG2 was identified as endo-PG releasing both methylesterified and non-methylesterified oligogalacturonides (OGs). Additionally, when flax roots were used as substrate, acetylated OGs were detected. The comparisons of OGs released from Verticillium-susceptible and partially resistant flax cultivars identified new possible elicitor of plant defence responses., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The objective of this work was to relate PM 2.5 Oxidative Potential (OP) data to PM composition and PM local and distant source contributions. PM 2.5 collected in Dunkerque, a coastal industrial city in North of France, was extensively characterized for major and minor chemical species. PM 2.5 filters were extracted using a synthetic pulmonary fluid to achieve OP estimation based on Ascorbic Acid (AA) and dithiothreitol (DTT) depletion assays. In order to evidence relationships between OP values, chemical composition and local and distant source contributions, correlation coefficient, Principal Component Analysis (PCA), concentration roses, polar plots and concentration weighted trajectories were used. Heterogeneous conclusions were drawn using the three first methods as the bivariate polar plots lead to dismiss some of the correlations evidenced using correlation coefficient and PCA. Both AA and DTT tests appeared complementary as they were not sensitive to the same species/source contribution. The bivariate polar plot representation of OP values versus wind direction and wind speed revealed that PM 2.5 concentration and combustion sources were linked to OP-AA, whereas emissions from integrated steelworks, electric steelworks, heavy fuel oil combustion and traffic non-exhaust significantly contribute to OP-DTT. Sea-salts, aged sea-salts, crustal, secondary sulfates and secondary nitrates sources were not found to contribute to OP values. Constant weighted trajectories evidenced several source regions responsible for high OP values with Belgium, Germany, Netherlands and France at the leader position. Contribution of inland regions appeared possibly related to the biomass and traffic related combustion while heavy fuel oil combustion could also be involved in the contribution of marine and coastal areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this article, a numerical workflow describing the microalgal growth inside of a photobioreactor is proposed. CFD is used to compute reactor internal hydrodynamics taking into account marine impeller rotation and sparged bubbles motion. Lagrangian approach is used to track microalgae motion inside of the culture vessel. The illumination across the reactor is obtained using the classical Beer-Lambert's law. The combination of light field and cell motion allows to reconstruct the light history of each microalgae. These histories are then supplied to Han's model which predicts individual growth rate and experienced photodamages. Once computed, several thousands of trajectories are agglomerated at the population level yielding the photobioreactor performances. After having ensured properties convergence, this procedure is applied to a large range of optical density (0 to 4.0), i.e. cell concentration, and incident light intensities (0 to 2000 μmolPhoton/m 2 /s). From this exploration, it is possible to determine the photobioreactor response surfaces in terms of growth rate and photodamages. These are latter used to propose an optimal lighting strategy for biomass production - reducing photobioreactor operation time by 16% compared to classical two-step procedure - and assist light induced stress with the aim of triggering secondary metabolites production., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest to declare., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

With the emergence of multi-drug resistant bacteria and hospital-acquired infections, there is an urgent need to develop new antibiotics. Here, we report the synthesis, physico-chemical characterizations, and antimicrobial activity assays of four Azo compounds that differ in their alkyl chain length. The molecular mechanism of their antibacterial activity was investigated by complementary in vitro and in silico biophysical studies. The compounds with alkyl chain lengths of four or six carbons showed a low MIC 50 against Escherichia coli and Bacillus subtilis. Our investigations into the mechanism of their action revealed that phosphatidylethanolamine in the bacterial plasma membrane plays an important role in their antibacterial activity., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Thermochemolysis of seven nucleobases-adenine, thymine, uracil, cytosine, guanine, xanthine, and hypoxanthine-in tetramethylammonium hydroxide (TMAH) was studied individually by pyrolysis gas chromatography mass spectrometry in the frame of the Mars surface exploration. The analyses were performed under conditions relevant to the Sample Analysis at Mars (SAM) instrument of the Mars Curiosity Rover and the Mars Organic Molecule Analyzer (MOMA) instrument of the ExoMars Rover. The thermochemolysis products of each nucleobase were identified and the reaction mechanisms studied. The thermochemolysis temperature was optimized and the limit of detection and quantification of each nucleobase were also investigated. Results indicate that 600°C is the optimal thermochemolysis temperature for all seven nucleobases. The methylated products trimethyl-adenine, 1, 3-dimethyl-thymine, 1, 3-dimethyl-uracil, trimethyl-cytosine, 1, 3, 7-trimethyl-xanthine (caffeine), and dimethyl-hypoxanthine, respectively, are the most stable forms of adenine, thymine, uracil, cytosine, guanine, and xanthine, and hypoxanthine in TMAH solutions. The limits of detection for adenine, thymine, and uracil were 0.075 nmol; the limits of detection for guanine, cytosine, and hypoxanthine were higher, at 0.40, 0.55, and 0.75 nmol, respectively. These experiments allowed to well constrain the analytical capabilities of the thermochemolysis experiments that will be performed on Mars to detect nucleobases., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Whereas freeze-drying is a widely used method to produce porous hydrogel scaffolds, the mechanisms of pore formation involved in this process remained poorly characterized. To explore this, we focused on a cross-linked polysaccharide-based hydrogel developed for bone tissue engineering. Scaffolds were first swollen in 0.025% NaCl then freeze-dried at low cooling rate, i.e. -0.1 °C min -1 , and finally swollen in aqueous solvents of increasing ionic strength. We found that scaffold's porous structure is strongly conditioned by the nucleation of ice. Electron cryo-microscopy of frozen scaffolds demonstrates that each pore results from the growth of one to a few ice grains. Most crystals were formed by secondary nucleation since very few nucleating sites were initially present in each scaffold (0.1 nuclei cm -3  °C -1 ). The polymer chains are rejected in the intergranular space and form a macro-network. Its characteristic length scale coincides with the ice grain size (160 μm) and is several orders of magnitude greater than the mesh size (90 nm) of the cross-linked network. After sublimation, the ice grains are replaced by macro-pores of 280 μm mean size and the resulting dry structure is highly porous, i.e. 93%, as measured by high-resolution X-ray tomography. In the swollen state, the scaffold mean pore size decreases in aqueous solvent of increasing ionic strength (120 µm in 0.025% NaCl and 54 µm in DBPS) but the porosity remains the same, i.e. 29% regardless of the solvent. Finally, cell seeding of dried scaffolds demonstrates that the pores are adequately interconnected to allow homogenous cell distribution. STATEMENT OF SIGNIFICANCE: The fabrication of hydrogel scaffolds is an important research area in tissue engineering. Hydrogels are textured to provide a 3D-framework that is favorable for cell proliferation and/or differentiation. Optimum hydrogel pore size depends on its biological application. Producing porous hydrogels is commonly achieved through freeze-drying. However, the mechanisms of pore formation remain to be fully understood. We carefully analyzed scaffolds of a cross-linked polysaccharide-based hydrogel developed for bone tissue engineering, using state-of-the-art microscopic techniques. Our experimental results evidenced the shaping of hydrogel during the freezing step, through a specific ice-templating mechanism. These findings will guide the strategies for controlling the porous structure of hydrogel scaffolds., (Copyright © 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

The discovery of molecules that can inhibit the action of phytopathogens is essential to find alternative to current pesticides. Pectin methylesterases (PME), enzymes that fine-tune the degree of methylesterification of plant cell wall pectins, play a key role in the pathogenicity of fungi or bacteria. Here we report the synthesis of new lactoside derivatives and their analysis as potential PME inhibitors using three plants and one fungal PME. Because of its structure, abundance and reduced cost, lactose was chosen as a case study. Lactoside derivatives were obtained by TEMPO-mediated oxidation of methyl lactoside, followed by an esterification procedure. Three derivatives were synthesized: sodium (methyl-lactosid)uronate, methyl (methyl-lactosid)uronate and butyl (methyl-lactosid)uronate. The inhibition of the plant and pathogen enzyme activities by lactoside derivatives was measured in vitro, showing the importance of the substitution on lactose: methyl (methyl-lactosid)uronate was more efficient than butyl (methyl-lactosid)uronate. These results were confirmed by docking analysis showing the difference in the interaction between lactoside derivatives and PME proteins. In conclusion, this study identified novel inhibitors of pectin remodeling enzymes., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this work, we present a new PDE model of the growth of Postia placenta, a species of brown rot fungus. The formulation was derived mainly from the biological mechanisms embedded in our discrete model, validated against experimental data. In order to mimic the growth mechanisms, we propose a new reaction-diffusion formulation, based on three variables: the concentration of tips, the branch density and the total hyphal density. The evolution of tips obeys a reaction-diffusion model, with constant diffusivity, while the evolution of the two other variables results from time integrals. The numerical solution is in excellent agreement with the averaged radial tip/hyphal densities of the mycelial network obtained by the discrete model. Thanks to the efficient exponential Euler method with Krylov subspace approximation, the solution needs only 3.5 s of CPU time to simulate 104-day of mycelium growth, in comparison with 8 hours for the discrete model. The great reduction of the RAM memory and computing time gives the possibility to upscale the simulation. The novelty of the PDE system is that the spatial colonization is formulated as a diffusion mechanism, which is self-standing, contrary to models based on an advection term. The continuous model can also reproduce the radial densities when the growth parameters in the discrete model are varied to adapt to different growth conditions. The correlation constructed between the two models provides us a tool for mutual insights between local biological mechanisms to the global biomass distribution, especially when analyzing experimental data., (Copyright © 2019. Published by Elsevier Ltd.)

Exposure to airborne particulate matter (PM) has significant effects on human health mainly leading to cardio-respiratory diseases. However very few data are available regarding the impact of PM on the skin, so to better understand the impact of fine particle (PM 0.3-2.5 ) on both inflammatory response and epidermal structure, we exposed a reconstructed human epidermis (RHE) to several doses of PM collected in Cotonou (Benin, West Africa). After 24 h of exposure, inflammatory response, histological observations, and gene expression related to oxidative stress, antioxidant defense and structural damages were determined. No PM-linked changes in tissue morphology or membrane integrity were observable. PM was however cytotoxic in a dose dependent manner. An inflammatory response appeared as shown by the increase in IL-1α and IL-8 cytokine productions. PM also induced oxidative stress, leading to an increase in 4-HNE immunostaining and to the up-regulation of HMOX1, MT1G and MT1E. Finally, PM had a negative impact on fundamental skin functions such as tissue anchorage, cell differentiation, cornification / skin desquamation and apoptosis. Our data show that airborne fine particles have an adverse effect on skin integrity, most probably leading to accelerated ageing., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Pectinases represent about one fifth of the enzyme worldwide market due their wide range of biotechnological applications. Current commercial pectinases are exclusively obtained from microbial sources, but here we report a pectin methylesterase (Sl-PME) and an endo-polygalacturonase (Sl-EPG) bioprospected from the sugarcane weevil, Sphenophorus levis, which revealed good potential for industrial applications. Sl-PME and Sl-EPG were overexpressed in Pichia pastoris, purified and enzymatically characterized. Sl-EPG presents optimal activity at pH 4-5 and 50 °C, showing that it can be used for juice extraction and clarification. On the other hand, Sl-PME presents optimal activity at pH 6-8 and 40 °C, and thus, suitable for both acidic and alkaline processing, such as coffee and tea fermentation. Sl-EPG shows V max  = 3.23 mM/min, K M  = 2.4 g/L and k cat  = 418.6 s -1 . While Sl-PME shows V max  = 0.14 mM/min, K M  = 4.1 g/L and k cat  = 1.7 s -1 . A PG inhibitor (PGIP2) weakly interfered in the Sl-EPG activity and Sl-PME was not affected by a usual PME inhibitor. Moreover, these enzymes manifested synergistic action towards methylesterified pectin. Here, we propose these enzymes as novel alternative tools for the current commercial pectinases., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This work provides a model and the associated set of parameters allowing for microalgae population growth computation under intermittent lightning. Han's model is coupled with a simple microalgae growth model to yield a relationship between illumination and population growth. The model parameters were obtained by fitting a dataset available in literature using Particle Swarm Optimization method. In their work, authors grew microalgae in excess of nutrients under flashing conditions. Light/dark cycles used for these experimentations are quite close to those found in photobioreactor, i.e. ranging from several seconds to one minute. In this work, in addition to producing the set of parameters, Particle Swarm Optimization robustness was assessed. To do so, two different swarm initialization techniques were used, i.e. uniform and random distribution throughout the search-space. Both yielded the same results. In addition, swarm distribution analysis reveals that the swarm converges to a unique minimum. Thus, the produced set of parameters can be trustfully used to link light intensity to population growth rate. Furthermore, the set is capable to describe photodamages effects on population growth. Hence, accounting for light overexposure effect on algal growth., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Anthropogenic inputs of trace elements (TE) into soils constitute a major public and environmental health problem. Bioavailability of TE is strongly related to the soil physicochemical parameters and thus to the ecosystem type. In order to test whether soil parameters influence the response of the bacterial community to TE pollution, we collected soil samples across contrasting ecosystems (hardwood, coniferous and hydromorphic soils), which have been contaminated in TE and especially lead (Pb) over several decades due to nearby industrial smelting activities. Bacterial community composition was analysed using high throughput amplicon sequencing and compared to the soil physicochemical parameters. Multivariate analyses of the pedological and biological data revealed that the bacterial community composition was affected by ecosystem type in the first place. An influence of the contamination level was also evidenced within each ecosystem. Despite the important variability in bacterial community structure, we found that specific bacterial groups such as γ-Proteobacteria, Verrucomicrobia and Chlamydiae showed a consistent response to Pb content across contrasting ecosystems. Verrucomicrobia were less abundant at high contamination level whereas Chlamydiae and γ-Proteobacteria were more abundant. We conclude that such groups and ratio's thereof can be considered as relevant bioindicators of Pb contamination., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Aided phytostabilization using coal fly ashes (CFAs) is an interesting technique to clean-up polluted soils and valorizing industrial wastes. In this context, our work aims to study the effect of two CFAs: silico-aluminous (CFA1) and sulfo-calcic (CFA2) ones, 10 years after their addition, on the phytostabilization of a highly Cd (cadmium), Pb (lead) and Zn (zinc) contaminated agricultural soil, with four forest tree species: Robinia pseudoacacia, Alnus glutinosa, Acer pseudoplatanus and Salix alba. To assess the effect of CFAs on trees, leaf fatty acid composition, malondialdehyde (MDA), oxidized and reduced glutathione contents ratio (GSSG: GSH), 8-hydroxy-2'-deoxyguanosine (8-OHdG), Peroxidase (PO) and Superoxide dismutase (SOD) activities were examined. Our results showed that CFA amendments decreased the CaCl 2- extractable fraction of Cd and Zn from the soil. However, no significant effect was observed on metal trace element (MTE) concentrations in leaves. Fatty acid percentages were only affected by the addition of sulfo-calcic CFA. The most affected species were A. glutinosa and R. pseudoacacia in which C16:0, C18:0 and C18:2 percentages increased significantly whereas the C18:3 decreased. The addition of sulfo-calcic CFA induced the antioxidant systems response in tree leaves. An increase of SOD and POD activities in leaves of trees planted on the CFA2-amended plot was recorded. Conversely, silico-aluminous CFA generated a reduction of lipid and DNA oxidation associated with the absence or low induction of anti-oxidative processes. Our study evidenced oxidative stress alleviation in tree leaves due to CFA amendments. MTE mobility in contaminated soil and their accumulation in leaves differed with the nature of CFA amendments and the selected tree species., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Smelting activities are one of the most common sources of trace elements in the environment. The aim of this study was to determine the lead distribution in upper horizons (0-5 and 5-10cm) of acidic soils in the vicinity of a lead-acid battery recycling plant in northern France. The combination of chemical methods (sequential extractions), physical methods (Raman microspectroscopy and scanning electron microscopy with an energy dispersive spectrometer) and multi-surface complexation modelling enabled an assessment of the behaviour of Pb. Regardless of the studied soil, none of the Pb-bearing phases commonly identified in similarly polluted environments (e.g., anglesite) were observed. Lead was mainly associated with organic matter and manganese oxides. The association of Pb with these soil constituents can be interpreted as evidence of Pb redistribution in the studied soils following smelter particle deposition., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Bio-based organic acids are promising renewable carbon sources for the chemical industry. However energy-consuming purification processes are used, like distillation or crystallization, to reach high purities required in some applications. That is why preparative chromatography was studied as an alternative separation technique. In a previous work dealing with the purification of lactic, succinic and citric acids, the Langmuir model was insufficient to explain the elution profiles obtained with a strong anionic resin. Consequently the Langmuir model was coupled with a usual ion-exchange model to take into account the retention of their conjugate bases (<2%), which are commonly neglected at low pH (<1.5). Elution simulations with both uptake mechanisms fitted very well with experimental pulse tests. Only two parameters were optimized (equilibrium constant of acid uptake and ion-exchange selectivity coefficient of conjugate base) and their value were coherent with experimental and resin suppliers' data. These results confirmed that the singular tailing and apparent delay observed with succinic and citric acids can be explained by the high affinity of succinate and citrate for resin cationic sites. The model was implemented in a preparative chromatography simulation program in order to optimize operating parameters of our pilot-scale ISMB unit (Improved Simulated Moving Bed). The comparison with experimental ISMB profiles was conclusive., (Copyright © 2016 Elsevier B.V. All rights reserved.)