Laboratoire Sols et Environnement

Environmental, economic, and safety challenges have provoked packaging scientists and producers to partially substitute petrochemical-based polymers with biodegradable ones. The general purpose of this review is to introduce poly-lactic acid (PLA), a compostable, biodegradable thermoplastic made from renewable sources. PLA properties and modifications via different methods, like using modifiers, blending, copolymerizing, and physical treatments, are mentioned; these are rarely discussed together in other reviews. Industrial processing methods for producing different PLA films, wrappings, laminates, containers (bottles and cups), are presented. The capabilities of PLA for being a strong active packaging material in different areas requiring antimicrobial and antioxidant characteristics are discussed. Consequently, applications of nanomaterials in combination with PLA structures for creating new PLA nanocomposites with greater abilities are also covered. These approaches may modify PLA weaknesses for some food packaging applications. Nanotechnology approaches are being broadened in food science, especially in packaging material science with high performances and low concentrations and prices, so this category of nano-research is estimated to be revolutionary in food packaging science in the near future. The linkage of a 100% bio-originated material and nanomaterials opens new windows for becoming independent, primarily, of petrochemical-based polymers and, secondarily, for answering environmental and health concerns will undoubtedly be growing with time.

This paper addresses the problem of stability analysis and control synthesis of switched systems in the discrete-time domain. The approach followed in this paper looks at the existence of a switched quadratic Lyapunov function to check asymptotic stability of the switched system under consideration. Two different linear matrix inequality-based conditions allow to check the existence of such a Lyapunov function. The first one is classical while the second is new and uses a slack variable, which makes it useful for design problems. These two conditions are proved to be equivalent for stability analysis. Investigating the static output feedback control problem, we show that the second condition is, in this case, less conservative. The reduction of the conservatism is illustrated by a numerical evaluation.

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See also the Commentary on this article by Jaffré et al., 218 : 397–400 .

Abstract The current concern for fat intake in western countries has raised the question of the individual fatty acid (FA) impact on health. This important issue has strengthened the awareness of nutritionists and food manufacturers for the control of the FA profile of food products. The aim of this review is to provide a classification of the FA profiles of 80 vegetable oil sources, according to their nutritional potential. The first part of the review focuses on lipoprotein metabolism, and on the impact of each dietary FA on blood lipid composition (LDL‐cholesterol, HDL‐cholesterol and circulating triacylglycerols). In the second part of the review, the oil sources are clustered by similar FA profiles, and the classification is discussed with regard to the individual FA action on blood lipid composition. Apart from the major vegetable seeds, the clustering highlighted some interesting nutritional oil sources containing mainly α‐linolenic acid (camelina, linseed, perilla and stock oils), or interesting amounts of the two essential FA (purslane, chia, raspberry seed, sea buckthorn seed and salicorn oils). Furthermore, this classification provides a useful tool for the formulation of the FA profile of food products.

During the hydraulic-fracturing experiment in the German Continental Deep Drilling Borehole (KTB) in December 1994, microseismic activity was induced. Here we develop a technique for estimating permeability using the spatio-temporal distribution of the fluid-injection-induced seismic emission. The values we have obtained for the KTB experiment (0.25 × 10−16 to 1.0 × 10−16 1.0 × 10−16 m2) are in a very good agreement with the previous hydraulic-type permeability estimates from KTB deep-observatory studies. In addition, our estimates of the hydraulic diffusivity support the previously calculated value for the upper crust, which is of the order of 1 m2 s-1. However, this estimate now relates to the depth range 7.5–9 km.

Increased environmental concerns over the use of certain synthetic packaging and coatings in combination with consumer demands for both higher quality and longer shelf life have led to increased interest in alternative packaging materials research. Naturally renewable biopolymers can be used as barrier coatings on paper packaging materials. These biopolymer coatings may retard unwanted moisture transfer in food products, are good oxygen and oil barriers, are biodegradable, and have potential to replace current synthetic paper and paperboard coatings. Incorporation of antimicrobial agents in coatings to produce active paper packaging materials provides an attractive option for protecting food from microorganism development and spread. The barrier, mechanical, and other properties of biopolymer-coated paper are reviewed. Existing and potential applications for bioactive coatings on paper packaging materials are discussed with examples.

Although urban and suburban soils are used for many purposes, some of them relevant to agricultural and forest sciences, that these intensively managed and disturbed soils have not been extensively investigated up to now is suggested by the white areas representing most urban zones on soil survey maps. Because urban soils are often developed on composite materials derived from previous uses and exogenous sources, spatial heterogeneity is a typical feature. Their evolution is controlled almost exclusively by humans, who impose very rapid transformation cycles compared with those occurring in less disturbed areas. However, there is a continuum from the natural soils to the extensively disturbed soils, and their basic functions are essentially the same. As a result of their origin and uses, urban soils may contain pollutants, the location, characteristics, and potential evolution of which must be established clearly to ensure safe land uses. These soils can be investigated with the traditional soil survey approach when the techniques are adapted properly to the urban context. A multidisciplinary approach is necessary to ensure that urban soils are well understood in order to ensure their optimum use.

Phytomining technology employs hyperaccumulator plants to take up metal in harvestable plant biomass. Harvesting, drying and incineration of the biomass generates a high-grade bio-ore. We propose that "agromining" (a variant of phytomining) could provide local communities with an alternative type of agriculture on degraded lands; farming not for food crops, but for metals such as nickel (Ni). However, two decades after its inception and numerous successful experiments, commercial phytomining has not yet become a reality. To build the case for the minerals industry, a large-scale demonstration is needed to identify operational risks and provide "real-life" evidence for profitability.

Cadmium is a non-essential trace metal, which is highly toxic to nearly all living organisms. Soil pollution causes Cd contamination of crops, thereby rendering plant products responsible for the chronic low level Cd over-exposure of numerous populations in the world. For this reason, Cd accumulation in plants has been studied for about five decades now. The research first focused on the relationships between plant and soil Cd levels, on the factors of the metal availability in soil, as well as the root uptake processes. Cd distribution in plant organs was also investigated, first using a macroscopic and eco-physiological approach, and then with the help of molecular biology tools, at both tissue and cell scales. Cadmium has no biological function and hijacks the transport pathways of micronutrients such as Fe, Mn, or Zn, in order to enter the plant through the roots and be distributed to all its organs. The study of the genes that control the influx and efflux of the Cd2+ ion in the cytosol, vacuoles, and vascular tissues has significantly contributed to the understanding of the metal root uptake and of its transfer to the aerial parts. However, the mechanisms responsible for its distribution to the different above-ground tissues and specially to fruits and seeds have yet to be clarified. This review summarizes current knowledge in order to present a detailed overview of Cd transport and storage, from the rhizosphere to the different organs and tissues of the plant.

Summary Biochar, the solid product of biomass pyrolysis, can be used as a soil amendment to stabilize metals in contaminated soils. The effects of biochar on the mobility of metals in soils are, however, poorly understood. To identify the predominant processes, we focused on (i) a possible kinetic limitation by transport in biochar particles, (ii) the evolution of biochar mineral phases and (iii) the effect of biochar on soil pH . Batch experiments were conducted to measure the sorption kinetics of copper ( Cu ), cadmium ( Cd ) and nickel ( Ni ) and the sorption‐desorption isotherms for lead ( Pb ), Cu , Cd , zinc ( Zn ) and Ni in a wood‐derived biochar. Sorption data were then compared with extraction test results using biochar with one acidic and one basic soil contaminated by Zn , Cd and Pb . Kinetic results showed that biochar particle sizes controlled metal sorption rate despite a similar specific surface area, which indicated a limitation by intra‐particle diffusion. Isotherms showed a partially reversible sorption to biochar following the order Pb > Cu > Cd ≥ Zn > Ni , which we explained primarily by the (co)precipitation of metals or their adsorption on specific biochar mineral phases. Effective metal immobilization was observed with biochar in both contaminated soils but could not be predicted from the sorption isotherms. This immobilization appeared to be governed by the soil pH increase, which induced a greater retention of metals on soil particles. Short‐term effects of biochar on contaminated soils may therefore be controlled by diffusion in biochar particles and by soil alkalinization processes.

Polycyclic aromatic hydrocarbons (PAHs) are possible contaminants in some former industrial sites, representing a potential risk to human health if these sites are converted to residential areas. This work was conducted to determine whether PAHs present in contaminated soils are transferred to edible parts of selected vegetables. Soils were sampled from a former gasworks and a private garden, exhibiting a range of PAH concentrations (4 to 53 to 172 to 1263 and 2526 mg PAHs kg-1 of dry soil), and pot experiments were conducted in a greenhouse with lettuce (Lactuca sativa L. var. Reine de Mai), potato (Solanum tuberosum L. var. Belle de Fontenay), and carrot (Daucus carota L. var. Nantaise). At harvest, above- and below ground biomass were determined and the PAH concentrations in soil were measured. In parallel, plates were placed in the greenhouse to estimate the average PAH-dust deposition. Results showed that the presence of PAHs in soils had no detrimental effect on plant growth. Polycyclic aromatic hydrocarbons were detected in all plants grown in contaminated soils. However, their concentration was low compared with the initial soil concentration, and the bioconcentration factors were low (i.e., ranging from 13.4 x 10(-4) in potato and carrot pulp to 2 x 10(-2) in potato and carrot leaves). Except in peeled potatoes, the PAH concentration in vegetables increased with the PAH concentration in soils. The PAH distribution profiles in plant tissues and in soils suggested that root uptake was the main pathway for high molecular weight PAHs. On the opposite, lower molecular weight PAHs were probably taken up from the atmosphere through the leaves as well as by roots.

is exceptionally rare globally, and known principally from the Copperbelt of Central Africa. Cobalt accumulation is also observed in a limited number of nickel (Ni) hyperaccumulator plants occurring on ultramafic soils around the world. None of the putative Cu or Co hyperaccumulator plants appears to comply with the fundamental principle of hyperaccumulation, as foliar Cu-Co accumulation is strongly dose-dependent. Abnormally high plant tissue Cu concentrations occur only when plants are exposed to high soil Cu with a low root to shoot translocation factor. Most Cu-tolerant plants are Excluders sensu Baker and therefore setting nominal threshold values for Cu hyperaccumulation is not informative. Abnormal accumulation of Co occurs under similar circumstances in the Copperbelt of Central Africa as well as sporadically in Ni hyperaccumulator plants on ultramafic soils; however, Co-tolerant plants behave physiologically as Indicators sensu Baker. Practical application of Cu-Co accumulator plants in phytomining is limited due to their dose-dependent accumulation characteristics, although for Co field trials may be warranted on highly Co-contaminated mineral wastes because of its relatively high metal value.

Hyperaccumulator plants are the material basis for phytoextraction research and for practical applications in decontaminating polluted soils and industrial wastes. China's high biodiversity and substantial mineral resources make it a global hotspot for hyperaccumulator plant species. Intensive screening efforts over the past 20 years by researchers working in China have led to the discovery of many different hyperaccumulators for a range of elements. In this review, we present the state of knowledge on all currently reported hyperaccumulator species from China, including Cardamine hupingshanensis (selenium, Se), Dicranopteris dichotoma (rare earth elements, REEs), Elsholtzia splendens (copper, Cu), Phytolacca americana (manganese, Mn), Pteris vittata (arsenic, As), Sedum alfredii, and Sedum plumbizincicola (cadmium/zinc, Cd/Zn). This review covers aspects of the ecophysiology and molecular biology of tolerance and hyperaccumulation for each element. The major scientific advances resulting from the study of hyperaccumulator plants in China are summarized and synthesized.

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Soils are extremely rich in biodiversity, and soil organisms play pivotal roles in supporting terrestrial life, but the role that individual plants and plant communities play in influencing the diversity and functioning of soil food webs remains highly debated. Plants, as primary producers and providers of resources to the soil food web, are of vital importance for the composition, structure, and functioning of soil communities. However, whether natural soil food webs that are completely open to immigration and emigration differ underneath individual plants remains unknown. In a biodiversity restoration experiment we first compared the soil nematode communities of 228 individual plants belonging to eight herbaceous species. We included grass, leguminous, and non-leguminous species. Each individual plant grew intermingled with other species, but all plant species had a different nematode community. Moreover, nematode communities were more similar when plant individuals were growing in the same as compared to different plant communities, and these effects were most apparent for the groups of bacterivorous, carnivorous, and omnivorous nematodes. Subsequently, we analyzed the composition, structure, and functioning of the complete soil food webs of 58 individual plants, belonging to two of the plant species, Lotus corniculatus (Fabaceae) and Plantago lanceolata (Plantaginaceae). We isolated and identified more than 150 taxa/groups of soil organisms. The soil community composition and structure of the entire food webs were influenced both by the species identity of the plant individual and the surrounding plant community. Unexpectedly, plant identity had the strongest effects on decomposing soil organisms, widely believed to be generalist feeders. In contrast, quantitative food web modeling showed that the composition of the plant community influenced nitrogen mineralization under individual plants, but that plant species identity did not affect nitrogen or carbon mineralization or food web stability. Hence, the composition and structure of entire soil food webs vary at the scale of individual plants and are strongly influenced by the species identity of the plant. However, the ecosystem functions these food webs provide are determined by the identity of the entire plant community.

The antimicrobial, insecticidal, and hemolytic properties of peptides isolated from the venom of the predatory ant Pachycondyla goeldii, a member of the subfamily Ponerinae, were investigated. Fifteen novel peptides, named ponericins, exhibiting antibacterial and insecticidal properties were purified, and their amino acid sequences were characterized. According to their primary structure similarities, they can be classified into three families: ponericin G, W, and L. Ponericins share high sequence similarities with known peptides: ponericins G with cecropin-like peptides, ponericins W with gaegurins and melittin, and ponericins L with dermaseptins. Ten peptides were synthesized for further analysis. Their antimicrobial activities against Gram-positive and Gram-negative bacteria strains were analyzed together with their insecticidal activities against cricket larvae and their hemolytic activities. Interestingly, within each of the three families, several peptides present differences in their biological activities. The comparison of the structural features of ponericins with those of well-studied peptides suggests that the ponericins may adopt an amphipathic α-helical structure in polar environments, such as cell membranes. In the venom, the estimated peptide concentrations appear to be compatible with an antibacterial activity in vivo. This suggests that in the ant colony, the peptides exhibit a defensive role against microbial pathogens arising from prey introduction and/or ingestion.P82414P82415P82416P82417P82418P82419P82420P82421P82422P82423P82424P82425P82426P82427P82428 The antimicrobial, insecticidal, and hemolytic properties of peptides isolated from the venom of the predatory ant Pachycondyla goeldii, a member of the subfamily Ponerinae, were investigated. Fifteen novel peptides, named ponericins, exhibiting antibacterial and insecticidal properties were purified, and their amino acid sequences were characterized. According to their primary structure similarities, they can be classified into three families: ponericin G, W, and L. Ponericins share high sequence similarities with known peptides: ponericins G with cecropin-like peptides, ponericins W with gaegurins and melittin, and ponericins L with dermaseptins. Ten peptides were synthesized for further analysis. Their antimicrobial activities against Gram-positive and Gram-negative bacteria strains were analyzed together with their insecticidal activities against cricket larvae and their hemolytic activities. Interestingly, within each of the three families, several peptides present differences in their biological activities. The comparison of the structural features of ponericins with those of well-studied peptides suggests that the ponericins may adopt an amphipathic α-helical structure in polar environments, such as cell membranes. In the venom, the estimated peptide concentrations appear to be compatible with an antibacterial activity in vivo. This suggests that in the ant colony, the peptides exhibit a defensive role against microbial pathogens arising from prey introduction and/or ingestion.P82414P82415P82416P82417P82418P82419P82420P82421P82422P82423P82424P82425P82426P82427P82428 high pressure liquid chromatography minimal inhibitory concentration trifluoroethanol Social insects have developed a number of defensive systems that prevent the development of disease within colonies. For example, bee propolis and royal jelly present antimicrobial properties (1Fujiwara S. Imai J. Fujiwara M. Yaeshima T. Kawashima T. Kobayashi K. J. Biol. Chem. 1990; 265: 11333-11337Abstract Full Text PDF PubMed Google Scholar, 2Fernandes A. Lopes C.A.M. Sforcin J.M. Funari S.R.C. J. Venom. Anim. Toxins. 1996; 3: 287-294Crossref Google Scholar), and the fecal pellets of termites inhibit the development of fungal pathogens (3Rosengaus R.B. Guldin M.R. Traniello J.F.A. J. Chem. Ecol. 1998; 24: 1697-1706Crossref Scopus (102) Google Scholar). Within ants, most species possess metapleural glands on the thorax whose secretions, spread over the ants and throughout the nest, have a broad spectrum of antimicrobial action (4Hölldobler B. Engel-Siegel H. Psyche. 1984; 91: 201-224Crossref Scopus (105) Google Scholar, 5Maschwitz U. Koob K. Schildknecht H. J. Insect Physiol. 1970; 16: 387-404Crossref Scopus (107) Google Scholar, 6Veal D.A. Trimble J.E. Beattie A.J. J. Appl. Bacteriol. 1992; 72: 188-194Crossref PubMed Scopus (57) Google Scholar, 7Mackintosh J.A. Flood J.A. Veal D.A. Beattie A.J. Austr. J. Entomol. 1999; 38: 124-126Crossref Scopus (6) Google Scholar). The mandibular gland secretions of some army ant species also have a dual defensive role against both predators and microbial attacks of brood (8Brown C.A. Watkins J.F. Eldridge D.W. J. Kansas Entomol. Soc. 1979; 52: 119-122Google Scholar). If these mechanisms control the proliferation of many bacteria and fungi in the nesting environment, the introduction of pathogens may also arise from alimentation, especially prey. Among ants, predators stricto sensu are overrepresented within the subfamily Ponerinae (9Hölldobler B. Wilson E.O. The Ants. Springer-Verlag, Berlin1990Crossref Google Scholar). Most of these species capture almost every encountered prey using their venom (10Orivel J. Souchal A. Cerdan P. Dejean A. Sociobiology. 2000; 35: 131-140Google Scholar), which contains peptides (and proteins) (9Hölldobler B. Wilson E.O. The Ants. Springer-Verlag, Berlin1990Crossref Google Scholar, 11Blum M.S. Hermann H.R. Bettini S. Arthropod Venoms. Springer-Verlag, Berlin1978: 801-869Crossref Google Scholar, 12Schmidt J.O. Piek T. Venoms of the Hymenoptera: Biochemical, Pharmacological and Behavioural Aspects. Academic Press, London1986: 425-508Crossref Google Scholar). Because these prey are then brought back to the nest immediately after immobilization, their potential infection by bacteria, fungi, or viruses may seriously affect the survival of ant colonies or induce extensive damages because of the high population density combined with the close genetic relationship of the individuals. The antibacterial property of ant venom has only been demonstrated in the fire ant, Solenopsis invicta, in whose venom alkaloids inhibit the growth of both Gram-positive and Gram-negative bacteria and presumably act as a brood antibiotic (12Schmidt J.O. Piek T. Venoms of the Hymenoptera: Biochemical, Pharmacological and Behavioural Aspects. Academic Press, London1986: 425-508Crossref Google Scholar, 13Jouvenaz D.P. Blum M.S. MacConnell J.G. Antimicrob. Agents Chemother. 1972; 2: 291-293Crossref PubMed Scopus (72) Google Scholar). Venoms of the wasp,Vespa crabro, honey bees, and various snakes contain antimicrobial peptides, but their functions have not been investigated (14Oren Z. Shai Y. Biochemistry. 1997; 36: 1826-1835Crossref PubMed Scopus (370) Google Scholar, 15Krishnakumari V. Nagaraj R. J. Peptide Res. 1997; 50: 88-93Crossref PubMed Scopus (62) Google Scholar, 16Juvvadi P. Vunnam S. Merrifield R.B. J. Am. Chem. Soc. 1996; 118: 8989-8997Crossref Scopus (104) Google Scholar, 17Blaylock R.S.M. Toxicon. 2000; 38: 1529-1534Crossref PubMed Scopus (26) Google Scholar). Finally, lycotoxins isolated from spider venom are the only antimicrobial peptides in venom for which a preventive role against infections arising from prey ingestion has been demonstrated (18Yan L. Adams M.E. J. Biol. Chem. 1998; 273: 2059-2066Abstract Full Text Full Text PDF PubMed Scopus (152) Google Scholar). Here we investigate the possible role of the venom of a predatory ant species in the prevention of microbial disease. The antimicrobial, insecticidal, and hemolytic properties of the venom of the arboreal ponerine ant, Pachycondyla goeldii, were studied. In total, 15 novel peptides, named ponericins, were purified, and their primary structures were fully characterized through amino acid sequencing and matrix-assisted laser ionization/desorption time-of-flight mass spectrometry analyses. According to their amino acid sequences, ponericins were classified into three families named ponericin G, W, and L. Ten peptides were synthesized to perform detailed analyses of their biological activities. The relationships of these peptides with known antimicrobial peptides are discussed. Whole venom reservoirs were dissected from P. goeldiiants collected in Petit Saut, French Guiana. After rinsing in water, they were stored at −20 °C until processed. The venom reservoirs were disrupted by ultrasonic waves in a 30% acetonitrile, 0.2% trifluoroacetic acid solution (10 μl/venom reservoir), and empty reservoirs and membranes were discarded by centrifugation. Whole venom was injected into a C18 reversed-phase column (5 μm, particle size; 220 × 2.1-mm column; Vydac), and separations were performed at a flow rate of 200 μl/min. Peptide elution was monitored at 215 nm. Collected fractions were vacuum-dried and tested for biological activity. First, the venom was separated into four fractions with a gradient consisting of 10–80% solvent B (80% acetonitrile in 0.1% trifluoroacetic acid) for 60 min. Solvent A was 0.1% aqueous trifluoroacetic acid. Second, the venom was further purified on the same column with a biphasic gradient of 10–25% solvent B for 10 min and 25–55% solvent B for 75 min to improve the separation of the peptides contained in the active fraction. The purified peptides were analyzed by matrix-assisted laser ionization/desorption time-of-flight (Voyager Elite; PerSeptive Biosystems, Inc., Framingham, MA) mass spectrometry as described by Seon et al. (19Seon A.A. Pierre T.N. Redeker V. Lacombe C. Delfour A. Nicolas P. Amiche M. J. Biol. Chem. 2000; 275: 5934-5940Abstract Full Text Full Text PDF PubMed Scopus (24) Google Scholar). Peptides were sequenced by automated Edman degradation using a Procise pulse-liquid protein sequencer (model 494; PerkinElmer Life Sciences). About 30–60 pmol of peptide were dried and solubilized in 10 μl of 0.1 m ammonium acetate buffer, pH 5.5. Carboxyl-terminal sequences were determined by digestion with carboxypeptidase Y and mass spectrometry analysis of the digestion products as described by Seon et al. (19Seon A.A. Pierre T.N. Redeker V. Lacombe C. Delfour A. Nicolas P. Amiche M. J. Biol. Chem. 2000; 275: 5934-5940Abstract Full Text Full Text PDF PubMed Scopus (24) Google Scholar). Ten peptides were synthesized by Fmoc (N-(9-fluorenyl)methoxycarbonyl) chemistry and purified by Synt:em Peptides and were to the isolated to some ponericin was synthesized in a with the The peptide was and at the the for of for Because and peptides present the same in their sequence for and for together with differences or but have activity the peptide was further analyzed to an of the biological activity of their in the and hemolytic action of 10 peptides from P. at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested at the tested each the tested concentration was and the to the of the of at the tested in a For each the tested concentration was and the to the of the of venom and an of each were tested for their antibacterial activity against Gram-negative and Gram-positive activity was determined by the in were with 10 μl of the After at were by the peptides were tested against a of Gram-negative and Gram-positive microbial the and fungi in activity was determined by the A of and with was with a of the at and into in were with μl of the were at °C to the of the inhibitory and for at °C or on the activity was also by the The fungal colonies were into the close to a with the and from growth of the fungal colonies after of was as fungal The minimal inhibitory concentration of the peptides and was determined by liquid and growth on the strains in In the growth the were determined by a from an concentration of by in a buffer, pH activity was performed as described In the liquid growth μl of a of bacteria were to μl of growth was in by an in after at °C or The concentrations tested for each peptide were in the of The are as the concentration at which bacteria and the concentration that growth P. C. P. J. Biol. Chem. Full Text PDF PubMed Google Scholar). B from the from honey bee venom, and from the of the were as control antibiotic peptides in the growth action of ponericins and are as the the concentration tested at which the bacteria and the that growth growth growth action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested melittin, and were as peptides in the growth are as the the concentration tested at which the bacteria and the that growth action was at the concentration tested in a melittin, and were as peptides in the growth A of was with of or in were with μl of the peptide solution and at °C to the of the hemolytic After at and were of each peptide or a of of each of the 10 peptides was solubilized in an peptide were injected into of cricket 10 or P. of an or a dried solution of acetonitrile and trifluoroacetic acid in a The to the of of the larvae after was by analysis A of the Press, Scholar). The were in a using a The four peptides, ponericins and were solubilized in with and trifluoroethanol at at concentrations of and The were and with a a and spectrum was from The and were the same and then from the The structure was from each spectrum using the analysis P. PubMed Scopus Google Scholar). antibacterial of the venom of P. action against both Gram-positive and Gram-negative strains at a of The venom was separated on a reversed-phase into four of which only an antibacterial activity against the of the peptides in demonstrated that of the collected antibacterial properties The active peptides present in were analyzed by matrix-assisted laser ionization/desorption time-of-flight mass or were further studied. In total, 15 peptides were characterized at the of their amino acid sequences using Edman The amino acid sequence was also possible for peptides present in For some of the analyzed peptides, carboxypeptidase Y were to or of the amino acid. The of the with the was as a control for each sequence peptides can be classified into three families to their primary structures The peptides were named ponericins G, W, or L to the most amino acid. Within each most of the peptides share a of sequence with each to or for ponericins G, W, or The sequence similarities were using and Ponericins and present the sequence with the of the ponericin G and W families to for and and from to for were classified in the families because they some sequence features with the further investigate the antibacterial spectrum and insecticidal activity of each 10 of these 15 peptides to from each were synthesized as and Whole venom was active against the tested microbial strains the fungi Among the the most Gram-positive bacteria were B. B. and the most Gram-negative The 10 peptides four of antibacterial action at a concentration of Ponericins and an action to that of venom and were active against the tested bacteria and the The to the peptides and For the of the growth against Gram-positive bacteria were also to those with venom, but at the tested these peptides were active against most of the Gram-negative Within was the only that not affect the The of peptides and was active against most of the Gram-positive strains but against the Gram-negative with the of P. and Finally, ponericin only a of the tested be that of the peptides were against the fungal as for peptides and were for further analyses. member of each peptide a activity spectrum was for which was active against only a Their were determined in both liquid and growth against Gram-positive and Gram-negative strains or by most of the peptides In the liquid growth and a activity against most of the and were In the growth were at the of peptide in a the same of were with a action of peptide against most of the tested the comparison of their in the growth with those of melittin, and as peptides that their antimicrobial activity or for The hemolytic activity of the venom and the 10 peptides was tested on both and at the same concentration as the antimicrobial activity spectrum the were the most Whole venom and three peptides and of both and and were active and hemolytic activity only against The peptides not exhibit hemolytic activity. The insecticidal properties of P. venom were only in C. 10 peptides insecticidal properties against A. were active against and with Among these four peptides, and were the only that P. the of against ants was a possible of these ants against their action injected of the 10 peptides on the and ant of P. of the 10 action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested action was at the concentration tested in a The concentration of each of the 10 peptides from to in the venom The from the growth in which the tested concentrations of each were and that most of the strains were that the antibacterial peptide in concentration to exhibit a antibacterial activity in the and concentration of the 10 synthesized peptides present in venom of P. of peptide venom of of ponericin was from the comparison of with the of the peptide of peptide present in venom was determined by the of the fractions to each peptide to the of a known of The concentration of each peptide was with a of the venom of by the to an The of ponericin was from the comparison of with the of the peptide in a The of peptide present in venom was determined by the of the fractions to each peptide to the of a known of The concentration of each peptide was with a of the venom of by the to an some structural features of the ponericins with known antibacterial peptides for which extensive structural have been we analyzed the of four peptides in and in The four peptides in as as in The for ponericin are as in In water, the are of a or structure with a nm. The in the of a solvent the of water, the of a high with a at and at and nm. The analysis of the in in a over for four peptides This the on the and of antibacterial peptides from ant 15 peptides, named ponericins and from the venom of the ponerine ant P. goeldii, present sequences not in were classified into three families to their primary structure ponericins G, W, and L. the of peptides, ponericins G, of action can be and have a action against the microbial strains and are also and are only active against some Gram-positive bacteria and and present insecticidal Ponericins G share sequence with using a of antimicrobial peptides that have been isolated from only families, and PubMed Scopus Google Scholar). the of the ponericins G the isolated from that can be as cecropin-like those isolated from C. M. J. S. A. P. J. Biol. 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ABSTRACT The heavy metal hyperaccumulator Thlaspi caerulescens is widespread in France on many kinds of sites and substrates, including Zn/Pb/Cd mine and smelter wastes, Ni-rich serpentine outcrops and a variety of nonmetalliferous soils. Thlaspi caerulescens is remarkable among the metallophytes of France because it accumulates Zn to high concentrations (almost always >0.1%, and often >1% in the dry matter) regardless of the total Zn concentration of the substrate. The extraordinary uptake of Zn from soils of normal Zn concentration draws attention to the need for studies of the mechanisms by which such mobilization and uptake can occur. Different populations of Thlaspi caerulescens in France show considerable variation in their ability to accumulate Cd; individuals in some populations contain as much as 0.1 to 0.4% Cd, the highest levels recorded in vascular plants. The hyperaccumulation of Ni (sometimes exceeding 1%) from serpentine soils in France is also noteworthy. Despite the generally low biomass, some very large individuals occur, giving good potential for selective breeding to improve the value of Thlaspi caerulescens for phytoremediation, especially of Cd. The high Zn uptake from all kinds of soils is a property shared by the related T. brachypetalum, and T. alpinum shows dual Zn- and Ni uptake, depending on the substrate. The extent to which other species of Thlaspi occurring in France exhibit metal accumulation is also discussed.

Urban compost application in agroecosystems enhances soil fertility but can also be a source of (micro)plastics, which are not completely removed during the composting process. Knowledge of the fate of these plastics in regularly-amended soils is thus an issue for the environmental management of these soils. The aims of this study were 1) to develop a method combining soil fractionation, microscopic observation and chemical characterization to follow the fate of plastics in soils and 2) to apply this method on a long-term experimental field, where municipal solid waste composts were applied every other year during 10 years. The presence of plastics was investigated within compost and soil fractions using morphological and analytical characterization by transmission electronic microscopy (TEM-EDX) and pyrolysis coupled to gas chromatography and mass spectrometry (Py/GC/MS). Specific features of plastics allowed us to distinguish these polymers from soil organic matter even in the <200 µm soil fractions. Ti and Ba detection associated with these features, as they are initially added during the polymer production, also constituted plastic tracers within organo-mineral fractions. Plastic fragments as detected by TEM were less abundant in the fine soil fractions compared to the coarsest ones. The abundance of styrene produced upon pyrolysis, used as a molecular tracer of plastics, also decreased relative to produced toluene according to the same particle size gradient. Our results evidenced that plastics and microplastics were present in the soil that was amended for 10 years with compost, while not in the control soil. MPs were mostly observed as individualized particles, present in the coarsest fractions as well as some of the fine soil fractions, but they were little associated with the soil matrix. They mostly did not show any degradation features such as microbial lysis. We thus suggest that their evolution in soil was mainly due to fragmentation. Our methodological approach provides tools to monitor the fate of microplastics over time and specify the contribution of such contaminants in soil amended with bio-based products.

SUMMARY A sequential alkali extraction procedure followed by ultrafiltration and quantitative 31 P nuclear magnetic resonance (NMR) spectroscopy was used to examine organic phosphorus in a Brown Chernozem, and an adjacent Gleysol developed under native prairie vegetation, and a Grey Luvisol formed under aspen forest in Saskatchewan, Canada. Differences in the nature of organic P in the native soils were related to moisture status and vegetation. In the grassland soils, a greater proportion of orthophosphate diester P was found in the bottom‐slope Gleysol. This difference was partly attributed to less favourable conditions for mineralization in the bottom slope soil compared with the mid‐slope Brown Chernozem. Teichoic acid P occurred only in the native Grey Luvisol (NMR δ p.p.m. 0.36‐0.95) under boreal forest and not under native grassland. At all three sites, soils under long‐term cultivation were also examined and while orthophosphate monoester P (83.4‐94.6% total Po), orthophosphate diester P (3.9–8.7% total Po) and teichoic acid P (12.7% total Po in forested Grey Luvisol) were detected in native soils, only orthophosphate monoester P was found in the corresponding soils that had been cultivated for 70–80 years. These findings suggest that orthophosphate diester P and teichoic acid P are more readily mineralized in the soil environment than orthophosphate monoester P forms.