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Editorial. L’agroécologie, une science, un concept, des pratiques culturales, un mouvement politique. Bref historique
No full textInternational audienceLe terme « agroécologie » s’adresse à la fois à une science, un concept, des pratiques culturales et des mouvements politiques. Il existe de nombreuses définitions de l’agroécologie qui varient d’une institution et d’un pays à l’autre. À la fin des années 1920, la tentative de fusionner l’agronomie et l’écologie est née avec le développement du domaine de l’écologie des cultures dont la principale préoccupation était d’associer des conditions optimales de culture avec la géographie des territoires. L’agronome américain B.M. Bensin est le premier à avoir publié le terme « agroécologie » en 1928. Jusque dans les années 60, le terme agroécologie faisait uniquement référence à une discipline purement scientifique. Ensuite, différentes branches de l’agroécologie se sont développées avec, notamment en 1969, la définition par E.P. Odum du concept d’agroécosystèmes, un écosystème domestiqué et géré par l’homme. L’agroécologie en tant que pratique agricole est apparue dans les années 1980. En 1995, M. Altieri propose de définir l’agroécologie comme « l’application des concepts et principes de l’écologie à la conception et à la gestion d’agroécosystèmes durables ». Depuis les années 2000, le caractère transdisciplinaire de l’agroécologie, qui allie sciences naturelles et sciences sociales, a pris de plus en plus d’importance. Le présent chapitre propose un aperçu de l’évolution des concepts, pratiques et sciences de l’agroécologie sur plus d’un siècle.Qu’est-ce que l’agroécologie ?Depuis sa première utilisation dans une publication par l’agronome américain d’origine russe B.M. Bensin en 1928, de nombreuses définitions du terme « agroécologie » se sont succédé, suscitant ainsi de multiples débats
Insights into Species Preservation: Cryobanking of Rabbit Somatic and Pluripotent Stem Cells
No full textInternational audienceInduced pluripotent stem cells (iPSCs) are obtained by genetically reprogramming adult somatic cells via the overexpression of specific pluripotent genes. The resulting cells possess the same differentiation properties as blastocyst-stage embryonic stem cells (ESCs) and can be used to produce new individuals by embryonic complementation, nuclear transfer cloning, or in vitro fertilization after differentiation into male or female gametes. Therefore, iPSCs are highly valuable for preserving biodiversity and, together with somatic cells, can enlarge the pool of reproductive samples for cryobanking. In this study, we subjected rabbit iPSCs (rbiPSCs) and rabbit ear tissues to several cryopreservation conditions with the aim of defining safe and non-toxic slow-freezing protocols. We compared a commercial synthetic medium (STEM ALPHA.CRYO3) with a biological medium based on fetal bovine serum (FBS) together with low (0-5%) and high (10%) concentrations of dimethyl sulfoxide (DMSO). Our data demonstrated the efficacy of a CRYO3-based medium containing 4% DMSO for the cryopreservation of skin tissues and rbiPSCs. Specifically, this medium provided similar or even better biological results than the commonly used freezing medium composed of FBS and 10% DMSO. The results of this study therefore represent an encouraging first step towards the use of iPSCs for species preservation
Analysis of Scientific and Press Articles Related to Cultured Meat for a Better Understanding of Its Perception
No full textInternational audienceCultured meat is presented by its advocates as a good alternative for consumers who want to be more ethically minded but who do not wish to change their diet. This novel food has become an emerging topic in both the scientific field and the press media. From a bibliometric analysis of scientific publications and on a sociometric analysis of the mainstream press, the aim of this study was to identify potential differences between the scientific view and the public perception. This research analyzed the publications indexed by SCI-EXPANDED in the Web of Science Core Collection database owned by Clarivate Analytics, for scientific literature analysis, and indexed by the Factiva database, for the press media. A total of 327 scientific publications were analyzed according to year of publication and country and institution of origin, also including coauthorships, co-citations, and scientific fields' and journals' networks. A knowledge mapping using VOSviewer was used to study the literature in the field. Based on Factiva, 12,900 press articles dealing with artificial meat, mainly in English, have been found through public databases. The main conclusion is that cultured meat is mainly developing in the USA and the UK, with other countries, such as China, observing the trend for potential future applications. Scientific articles seemed initially to focus mainly on technical aspects of artificial meat and more recently on health value, consumer's acceptance, and sustainability. However, the potential environment-friendly effects of this novel food are more and more studied or described in scientific or press articles
Biopreservation of emulsified food and cosmetic products by synergistic action of probiotics and plant extracts: a Franco-Bulgarian perspective
No full textInternational audienceIn the context of growing interest for functional foods and cosmetic products, emulsified products such as dressings or lotions have been proposed to deliver probiotics and plant extracts with interesting biological (e. g. anti-inflammatory) properties due to their daily consumption or application on skin, respectively. Besides these positive effects, emulsified products containing water are often prone to microbial growth justifying thus the addition of preservatives such as parabens in their formulation. Safety concerns regarding some synthetic preservatives have stimulated the development of natural antimicrobial ingredients (namely from plant or microbial origin) for the preservation of food or cosmetic products. Besides direct addition of antimicrobial biomolecules, the addition of living bioprotective bacteria such as probiotic lactic acid bacteria (LAB) is a promising approach. Franco-Bulgarian ESCAPE project ambition is to identify synergistic combinations of such probiotic LAB and plant extracts for the preservation of food or cosmetic emulsions. The methodology and the relevant scientific questions (application of hurdle technology principles, selection of plant extracts not affecting LAB growth/viability and antimicrobial activity, distribution of LAB and antimicrobial metabolites in the different phases of emulsions, effect of LAB and plant extracts on emulsions stability…) to tackle this objective are presented and discussed
Use of Lactococcus lactis Subsp. Lactis Strains to Inhibit the Development of Pathogens
No full textInternational audienceBovine mastitis affects the udder health and thus causing significant economic losses. Probiotic products based on the use of lactic acid bacteria (LAB) to limit pathogens multiplication and pre-infection risks can be an interesting alternative to post infection allopathic treatment with antibiotics. Lactococcus lactis is one of the most important bacteria used in dairy technology. In this work, a total of 21 Lactococcus lactis subsp. lactis strains, 20 from goat milk whey and one strain from cow milk were used to evaluate their antibacterial activity against four pathogenic germs responsible for mastitis: Escherichia coli, Staphylococcus aureus, Streptococcus uberis and Streptococcus agalac-tiae. The nisin-producing cow milk strain was active against St. uberis and Str. agalactiae using the well diffusion method. For the strains isolated from goat milk whey, no antimicrobial effect was observed against these pathogens. However, a different approach based on the growth of pathogenic bacteria interacting with the Lactococcus lactis strains in a minimum medium was used to study the barrier effect of LAB. The Lactococcus lactis strains S1 and S2 from goat milk whey depleted the growth of Sa. aureus, St. uberis and E. coli during 8 h and stopped the development of St. agalactiae
A multi-method approach for the integrative assessment of soil functions: Application on a coastal mountainous site of the Philippines
No full textInternational audienceThe projected increase of the world's population and the sustainability challenges the agricultural sector is facing, call for the enhancement of multi-functionality in agriculture in order to simultaneously provide food while meeting environmental targets. Here, we use the Functional Land Management (FLM) framework to assess the supply of and the demand for soil functions to inform agri-environmental policy for Udalo, a mountainous site in the Philippines. As many emerging communities in developing nations, Udalo is on the cusp of rapid development due to the construction of a major road increasing its accessibility and attractiveness for land investment. We assessed the supply of four soil functions in relation to six land-use types and four slope categories. The function "productivity" was assessed by interviews with 128 farmers, "habitat for biodiversity" by a vegetation survey, and "soil conservation" and "water conservation" via a literature review. The demand for functions was first assessed from the "top-down" policy perspective via interviews and reviews of policy targets, then complemented by integrating the local "bottom-up" demands for functions. These were assessed by applying a Q methodology, providing insights in the prioritisation of functions from the perspective of 22 local actors. Maps of supply and demands were generated for each function: supply maps by overlaying land use and slope category, top-down demand maps from administrative zoning/land-use plans, and bottom-up demand maps from local actors designation of geomorphological areas. Our results revealed contrasting demands for functions, as well as a heterogeneous spatial distribution of supply and demands. Discrepancies emerged (i) between supply and demand, (ii) between bottom-up (local) demands and the top-down (policy driven) demand, and (iii) among local actors perspectives. Our study indicates that discrepancies are not necessarily conflicting, but can uncover pathways for defining compromises, representing attainable policy entry points. Not one single development model can meet the needs of every stakeholder; however, a combination of land uses and management strategies can meet divergent interests and allow for optimisation of functions. This integrative approach of FLM provides a socially embedded biophysical analysis and is a valuable tool for the design of customized land-use and agri-environmental policies
Lecture d'actualité : Des arguments scientifiques face aux interrogations à propos de l'élevage Présentation de l'ouvrage collectif « L'élevage pour l'agroécologie et une alimentation durable »
No full textInternational audienceThe book "Livestock for agro-ecology and sustainable food" is the result of a collaboration between many researchers and professionals. In this book, they analyze issues related to livestock farming and produce objective knowledge to enlighten the debates on this societal subject. Intended for all stakeholders concerned (farmers, professionals, students, teachers, public decision-makers, consumers and citizens), its aim is to propose avenues for progress and help support public policy. The book, briefly treated in this article, is divided into two main parts: 1) Livestock farming today and societal issues, and 2) Prospects for the evolution of livestock farming.Fruit de la collaboration de nombreux chercheurs et professionnels, l’ouvrage « L’élevage pour l’agroécologie et une alimentation durable » analyse les questions liées à l’élevage et produit des connaissances permettant d’objectiver les débats autour de ce sujet de société. Destiné à toutes les parties prenantes concernés (éleveurs, industriels, étudiants, enseignants, décideurs publics, consommateurs et citoyens), il a pour objectif de proposer des pistes de progrès et de contribuer à éclairer les politiques publiques. L’ouvrage, dont les thèmes traités sont succinctement abordés dans cet article, a été structuré en deux grandes parties : 1) L’élevage aujourd’hui et les questionnements sociétaux, 2) Les perspectives d’évolution de l’élevage
Valorisation de sous-produits végétaux par fermentation pour la production de composés à valeur ajoutée : Production d’acide L-lactique par fermentation de pulpe de carottes
No full textSustainable development and waste management issues are increasingly being considered in our societies. In this context, it is necessary to develop research to enrich scientific knowledge and enabling the development of efficient valorisation systems. Among the valorisation ways for the recycling of plant by-products from the food industry, fermentation can be used for the production of value-added compounds. My Ph D thesis project was carried out with the support of five food companies who wish to investigate specific valorisation routes for their by-products: Charles et Alice, Florette, Panzani, Philibert Savours and Pierre Martinet. The corresponding by-products are apple skins, salad peelings, wheat bran, wheat germ sourdough, and carrot pulp, respectively. First, matrix-specific physico-chemical (pH, water content, water activity (aW)), biochemical (nitrogen fractions, titratable acidity), and biological (microbial flora of the raw products) characteristics were determined. Coupled with spontaneous fermentation trials, the results enabled the selection of carrot pulp as a reference matrix, for further experiments. Incubation parameters of the spontaneous fermentation of carrot pulp were then varied according to a factorial experimental design. The results made it possible to select the fermentation conditions for the other four by-products. Acidity measurements (pH and titratable acidity) and monitoring of microbial flora over time showed the fermentability of by-products. For carrot pulp, the selected culture parameters (grinding of raw material, temperature, percentage of water and refreshments) and the levels set did not favour the production of molecules of interest among those monitored: phenolic compounds, organic acids, and volatile compounds. A screening allowed to isolate a L-lactic acid producing Lactobacillus strain from carrot pulp. The selected Lactobacillus paracasei A1L strain showed its ability to produce L-lactic acid in higher quantities than in spontaneous fermentation, however this concentration remains too low for an industrial application (maximum quantity produced = 0,974 g/L). Trials built according to a D-optimal experimental design tested the effect of temperature, pH, enzyme addition (hemicellulase and protease) and inoculum load. The results show that L-lactic acid production is favoured at a temperature of 25°C, an initial pH of 8, and a 10E+8 CFU/mL amount of microorganisms inoculated. The knowledge acquired on the dynamics of spontaneous fermentation or fermentation after inoculation, are elements that will allow to adapt the fermentation conditions in the futureLes enjeux de développement durable et de gestion des déchets sont de plus en plus considérés dans nos sociétés. Dans ce contexte, il est nécessaire de développer des recherches dans le but d’enrichir les connaissances scientifiques, et permettre de développer des systèmes de valorisation efficients. Parmi les voies de valorisation pour le recyclage des sous-produits végétaux, issus de l’industrie agroalimentaire, la fermentation peut être utilisée pour la production de métabolites à valeur ajoutée. Le projet dans le cadre duquel j’ai préparé ma thèse a été mené avec l’appui de cinq industriels du secteur agroalimentaire qui souhaitaient travailler sur la valorisation spécifique de leurs sous-produits végétaux : Charles et Alice, Florette, Panzani, Philibert Savours et Pierre Martinet. Les sous-produits associés sont respectivement des peaux de pommes, des épluchures de salades, du son de blé, du levain de germe de blé et de la pulpe de carottes. Dans un premier temps, des caractéristiques physico-chimiques (pH, teneur en eau, aw), biochimiques (acidité titrable, fractions azotées), et biologiques (flores microbiennes des produits bruts) de chacune de ces 5 matrices ont été déterminées. Couplé à des essais de fermentation spontanée, les résultats ont dans un premier temps permis de sélectionner une matrice de référence, la pulpe de carottes. La fermentation spontanée des sous-produits a été étudiée en faisant varier les paramètres d’incubation, selon un plan d’expérience factoriel, pour la matrice modèle. Les observations réalisées ont permis de sélectionner les conditions de fermentation des quatre autres sous-produits. Les mesures d’acidité (pH et acidité titrable) et le suivi de flores microbiennes au cours du temps ont montré la fermentescibilité des sous-produits. Pour la pulpe de carotte, les paramètres de culture choisis (broyage, température, pourcentage d’eau et rafraîchis) et les niveaux fixés, n’ont pas permis de favoriser la production de molécules d’intérêt parmi celles suivies : les composés phénoliques, les acides organiques et les composés volatils. En accord avec les partenaires du projet, la troisième partie avait pour objectif de sélectionner une souche de Lactobacillus, à partir de la matrice modèle, pour produire de l’acide L-lactique. La souche de Lactobacillus paracasei A1L sélectionnée a montré sa capacité à produire de l’acide L-lactique dans des quantités plus importantes qu’en fermentation spontanée, bien que celles-ci restent faibles pour envisager une application industrielle (quantité maximale produite = 0,974 g/L). Les essais réalisés selon un plan d’expérience D-optimal ont permis d’évaluer les effets de la température, du pH, de l’ajout d’enzymes (hémicellulase et protéase) et du taux d’ensemencement. Les résultats montrent que la production d’acide L-lactique est favorisée à une température de 25°C, un pH initial de 8 et une quantité de microorganismes ensemencée de 10E+8 UFC/mL. Au terme du projet, les connaissances acquises sur les dynamiques de fermentation, spontanée ou dirigée, sont des éléments qui permettront d’adapter les conditions de fermentatio
Cryopreservation d'embryons bovins dans un milieu chimiquement défini
No full textInternational audienceEmbryo cryopreservation media often contain an animal-derived component, such as bovine serum albumin (BSA) or fetal calf serum. However, the industry is faced with the issue of composition variability between batches and, most importantly, the risk of pathogen transmission. The aim of this study was to compare the effectiveness of two embryo cryopreservation ethylene glycol-based media: IMV’s freezing medium with BSA (IMV Technologies) and a chemically defined medium containing STEMALPHA.CRYO3, called CRYO3 (Ref 5617, Stem Alpha). CRYO3 is produced according to EU good manufacturing practice, ensuring the composition and quality of the product. Bovine morulae were collected in vivo and split into two groups to be slow frozen in both media. All results were analysed with chi-squared tests with Yates’s correction. For the in vitro approach of this study, frozen morulae (n ¼ 86) were thawed, cultured in medium (1:1:1 mixture of RPMI, Dulbecco’s modified Eagle’s medium, and Ham’s F10) at 38.58C with 5% CO2, and monitored every 24 h for 72 h to evaluate survival and expansion rates. Survival rate was higher in the CRYO3 group than in the BSA group (74 and 50%, respectively; P , 0.05). Expansion and hatching rates followed the same trend: 38 and 14%, respectively, at 48 h (P , 0.05) and 40 and 18% at 72 h (P , 0.05). For the in vivo approach of this study, frozen morulae (n ¼ 123) were thawed and transferred on the field to evaluate pregnancy and calving rates. Field results showed no significant difference between CRYO3 and the BSA-based medium for pregnancy rates (73 and 63%; P ¼ 0.3006) nor for the delivery rates (64 and 55%; P ¼ 0.3614).The trial was conducted with different AI teams and in 10 commercial herds, thus adding robustness to the data. This study has shown that CRYO3 can replace BSA in an ethylene glycol cryopreservation medium for in vivo-produced bovine embryos. Therefore, this product eliminates some sanitary risk in embryo commerce, which is a concern in an international context