Etude de la fertilite potentielle des eaux du lac de Parentis-Biscarrosse a l'aide de bio-essais avec les algues

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Using bibliometrics to analyze the state of art of pesticide use in vineyard agrosystems: a review

International audienceThe production of wine dates to ancient civilization and has heavily influenced different landscapes around the globe. Nowadays, wine is still an important sector in terms of land use and income source in many countries, more specifically in the European Mediterranean region. However, to control pests and regulate wine growth, the extensive use of pesticides is common. The effects and persistence of agrochemicals in the environment is well known and defined in scientific literature as well as the environmental and human health risks of these compounds. The purpose of this review was to do a state of art of worldwide production of academic literature using bibliometric principles and analysis to identify thematic areas of this type of agriculture, and its challenges in a changing world. For this review, the focus is on current practices to see what may evolve for more sustainable viticulture. It was found that the three main producers of wine, i.e., Spain, France, and Italy, are also three top producers of scientific literature on this topic. The use of bibliometric methodologies defined the main thematic areas on this subject as follows: soil-plant transfer of agrochemicals, heavy metal accumulation in vineyard soils, management practices in viticulture, water pollution transport, effects of viticulture on the living part of soil, sustainable alternatives to pesticides. We found that Spain, France, and Italy work the most on developing sustainable alternatives for agricultural practices; however, sustainable alternatives and practices were also the least developed thematic in general

Biological Removal and Fate Assessment of Diclofenac Using <i>Bacillus subtilis</i> and <i>Brevibacillus laterosporus</i> Strains and Ecotoxicological Effects of Diclofenac and 4′-Hydroxy-diclofenac

Since bacterial consortia involved in conventional wastewater treatment processes are not efficient in removing diclofenac (DCF), an emerging pollutant frequently detected in water bodies, the identification of microorganisms able to metabolise this pharmaceutical compound is relevant. Thus, DCF removal was investigated using bacteria isolated from aqueous stock solutions of this micropollutant and identified as Bacillus and Brevibacillus species using 16S rRNA gene sequencing. A 100% DCF removal was achieved after 17 hours of experiment at 20°C in a nutrient medium; the biodegradation kinetic followed a pseudo-first order (kbiol = 11 L·gSS−1·d−1). Quantitative assessment of DCF removal showed that its main route was biotic degradation. The main degradation product of DCF, 4′-hydroxy-diclofenac (4′-OH-DCF), was identified using liquid chromatography-electrospray ionisation high-resolution mass spectrometry. Since the ecotoxicological impact of 4′-hydroxy-diclofenac was not reported in the literature, the ecotoxicity of DCF and its metabolite were tentatively evaluated using Vibrio fischeri bioassays. Results from these tests showed that this metabolite is not more toxic than its parent compound and may hopefully be an intermediate product in the DCF transformation. Indeed, no significant difference in ecotoxicity was observed after 30 min between DCF (50 should be writtten in subscript all along the manuscript in EC50 = 23 ± 4 mg·L−1) and 4′-hydroxy-diclofenac (EC50 = 19 ± 2 mg·L−1). Besides, the study highlighted a limit of the Microtox® bioassay, which is largely used to assess ecotoxicity. The bioluminescence of Vibrio fischeri was impacted due to the production of microbial activity and the occurrence of some carbon source in the studied medium.</jats:p

Biological Removal and Fate Assessment of Diclofenac Using Bacillus subtilis and Brevibacillus laterosporus Strains and Ecotoxicological Effects of Diclofenac and 4′-Hydroxy-diclofenac

Since bacterial consortia involved in conventional wastewater treatment processes are not efficient in removing diclofenac (DCF), an emerging pollutant frequently detected in water bodies, the identification of microorganisms able to metabolise this pharmaceutical compound is relevant. Thus, DCF removal was investigated using bacteria isolated from aqueous stock solutions of this micropollutant and identified as Bacillus and Brevibacillus species using 16S rRNA gene sequencing. A 100% DCF removal was achieved after 17 hours of experiment at 20°C in a nutrient medium; the biodegradation kinetic followed a pseudo-first order (kbiol = 11 L·gSS−1·d−1). Quantitative assessment of DCF removal showed that its main route was biotic degradation. The main degradation product of DCF, 4′-hydroxy-diclofenac (4′-OH-DCF), was identified using liquid chromatography-electrospray ionisation high-resolution mass spectrometry. Since the ecotoxicological impact of 4′-hydroxy-diclofenac was not reported in the literature, the ecotoxicity of DCF and its metabolite were tentatively evaluated using Vibrio fischeri bioassays. Results from these tests showed that this metabolite is not more toxic than its parent compound and may hopefully be an intermediate product in the DCF transformation. Indeed, no significant difference in ecotoxicity was observed after 30 min between DCF (50 should be writtten in subscript all along the manuscript in EC50 = 23 ± 4 mg·L−1) and 4′-hydroxy-diclofenac (EC50 = 19 ± 2 mg·L−1). Besides, the study highlighted a limit of the Microtox® bioassay, which is largely used to assess ecotoxicity. The bioluminescence of Vibrio fischeri was impacted due to the production of microbial activity and the occurrence of some carbon source in the studied medium

Evaluation of an integrated constructed wetland to manage pig manure under Mediterranean climate

International audiencePig manure is a complex mixture with excessive nutrients such as ammonium, microbial pathogens and may contain contaminants such as antibiotics. Conventional pig manure management practices caused water contamination. Sludge treatment wetland has been evaluated to determine its potential use under Mediterranean climate aiming at a parsimonious use of water and preventing water contamination, two major steps to preserve water resources in the Mediterranean Basin. Preliminary NH 4-N degradation was tested using aeration process and/or addition of commercial bacterial products. Aeration alone appeared to be sufficient to ensure nitrogen transformation of the pig manure at lab small-scale (10 L) and medium-scale (300 L). Selected plant species e.g., Carex hispida for use in the integrated constructed wetland tolerated the nitrogen content after aeration enabling their use in a treatment vertical bed

Current status and future trends of microbial and nematode-based biopesticides for biocontrol of crop pathogens

International audienceThe increasing public demand to avoid the use of synthetic pesticides and fertilizers in agricultural production systems, causing serious environmental damages, has challenged industry to develop new and effective solutions to manage and control phytopathogens. Biopesticides, particularly microbial-based biopesticides, are a promising new alternative with high biodegradability, specificity, suitability for incorporation into integrated pest management practices, low likelihood of resistance development, and practically no known human health risks. However: expensive production methods, narrow action spectra, susceptibility to environmental conditions, short shelf life, poor storage stability, legislation registry constraints, and general lack of knowledge are slowing down their adoption. In addition to regulatory framework revisions and improved training initiatives, improved preservation methods, thoughtfully designed formulations, and field test validations are needed to offer new microbial- and nematode-based biopesticides with improved efficacy and increased shelf-life. During the last several years, substantial advancements in biopesticide production have been developed. The novelty part of this review written in 2023 is to summarize (i) mechanisms of action of beneficial microorganisms used to increase crop performance and (ii) successful formulation including commercial products for the biological control of phytopathogens based on microorganisms, nematode and/or metabolite

Statistical Experimental Design as a New Approach to Optimize a Solid-State Fermentation Substrate for the Production of Spores and Bioactive Compounds from Trichoderma asperellum

International audienceManaging organic agricultural wastes is a challenge in today’s modern agriculture, where the production of different agricultural goods leads to the generation of large amounts of waste, for example, olive pomace and vine shoot in Mediterranean Europe. The discovery of a cost-effective and environment-friendly way to valorize such types of waste in Mediterranean Europe is encouraged by the European Union regulation. As an opportunity, organic agricultural waste could be used as culture media for solid-state fermentation (SSF) for fungal strains. This methodology represents a great opportunity to produce secondary metabolites like 6-pentyl-alpha-pyrone (6-PP), a lactone compound with antifungal properties against phytopathogens, produced by Trichoderma spp. Therefore, to reach adequate yields of 6-PP, lytic enzymes, and spores, optimization using specific agricultural cheap local wastes from Southeastern France is in order. The present study was designed to show the applicability of an experimental admixture design to find the optimal formulation that favors the production of 6-PP. To conclude, the optimized formulation of 6-PP production by Trichoderma under SSF contains 18% wheat bran, 23% potato flakes, 20% olive pomace, 14% olive oil, 24% oatmeal, and 40% vine shoots

Coastal environments shape chemical and microbial properties of forest litters in circum Mediterranean region

International audienceThis study explores how chemical and microbial properties of litters can be affected by coastal environments across the Mediterranean basin. A litterbag experiment including Pinus halepensis Mill. and Pistacia lentiscus L., collected from both inland and coastal areas was set up in France, Greece and Algeria. Control litterbags were left in their sampling sites and a transfer of litterbags from inland to coastal area was performed to test whether the effect of the specific constraints of coastal environments varies according to the country and the litter type. After 10 months, litter chemical composition (CP/MAS 13 C-NMR) and microbial activities (cellulase, respiration, Biolog) and structure (TRFLP) were analysed. Coastal conditions led to various responses: i) litter aromaticity differed in the coastal zones depending on the country (high in Greek coastal area, low in Algerian coastal zone), ii) less functionally-diversified microbial communities were found in Greek coastal area compared to French and Algerian coasts, iii) genetic diversity and richness were strongly impacted after transfer to the coastal zone whatever the country. The type of litter shaped microbial communities: i) at a local scale i.e. in either coastal or inland area, catabolic profiles and cellulase activities varied with the plant species, ii) at a regional scale, the effect of coastal conditions differed with the plant species (basal respiration, Shannon-Weaver index, catabolic diversity H', cellulases and catabolic profiles). Thus, litter microbial properties differed in coastal environments across the Mediterranean basin and plant litter type plays a major role in microbial properties at large spatial scale

Challenges in viticulture practices in a changing environment: Can green waste amendment benefit soil properties of vineyards in the Mediterranean?

International audienceIn Southeastern France, viticulture is of great social, cultural, and economic importance. This sector is threatened by climate change particularly in the Mediterranean (longer droughts and more frequent heat waves) where soils are poor in organic matter and weakly developed. Since organic amendment can strongly modify soil properties and consequently the final products (grapes and wine), the effects of sustainable practices on soil characteristics have to be carefully assessed. This seasonal field survey focuses on the effects green waste amendment (GWA), i.e. semi-composted green wastes, have on vineyard soil functionality. The effects of GWA were compared with those of grass cover (GC), known as a sustainable practice. Soils were collected in vineyards under organic practices (Bouches-du-Rhône and Var, France) over four seasons and physico-chemical (Total C and N, pHwater, pHKCL, EC, WHC, copper content and soil organic carbon SOC) and biological (microbial respiration and biomass, microbial catabolic structure, earthworm abundance and biomass) properties were characterized. Both practices were beneficial to soil physicochemical properties. For example, under both practices, higher (2 fold) Total N and SOC on late spring were observed. Both GWA and GC favored soil microbial communities, with microbial respiration having doubled and tripled on late spring. Similar results were observed for microbial biomass and both bacterial and fungal catabolic diversities (increased approximately by half) over summer. These benefits were particularly prominent during drought season (June and August), and probably linked to a shift in microbial communities as revealed by catabolic profiles. GWA also favored abundance and biomass of earthworm during winter. These findings reveal the potential GWA to counteract the effect of tillage, to mitigate the stress from drought and to improve overall soil functionality in vineyards