Comparison of explant responses treated with leachate and leonardite sources of humic substances during in vitro rooting of woody plants.

As heterogeneous mixtures of compounds resulting from the physical, chemical and microbiological transformations of organic residues, humic substances (HS) are mostly recognized for their biostimulation of plant growth that firstly involve the root development and architecture before further putative improvement of nutrients uptakes. To avoid the interferences currently reported from external origins, the successive steps of rooting have been carried out using shoots and isolated leaves of birch and alder vitro-plants. Extracts issued from landfill leachate (LHS) has been compared to a stable formulation from leonardite ("Humifirst" 12% humic acid 3% and fulvic acid) commercialized by TRADECORP company's (HHS). Chemical analysis showed that LHS source typically contain much higher N (mainly as ammonium (93%) and chloride concentration than HHS. Used at low concentration (10 ppm) during root induction/initiation phase, both HS sources may be slightly unfavorable to the root formation (21% of reduction in primary root number) of alder but not of birch. While, in root elongation phase, there is an increase in the primary root length and lateral root number. The direct effects of HS on in vitro root development vary from one species to another depending on the root treatment stage. Results showed that both explants type response are equivalent in the development of a complete rooting system

Preliminary evaluation of antimicrobial activity of some chemicals on in vitro apple shoots infected by 'Candidatus Phytoplasma mali'.

peer reviewe

Tissue Resources for the Functional Annotation of Animal Genomes

In order to generate an atlas of the functional elements driving genome expression in domestic animals, the Functional Annotation of Animal Genome (FAANG) strategy was to sample many tissues from a few animals of different species, sexes, ages, and production stages. This article presents the collection of tissue samples for four species produced by two pilot projects, at INRAE (National Research Institute for Agriculture, Food and Environment) and the University of California, Davis. There were three mammals (cattle, goat, and pig) and one bird (chicken). It describes the metadata characterizing these reference sets (1) for animals with origin and selection history, physiological status, and environmental conditions; (2) for samples with collection site and tissue/cell processing; (3) for quality control; and (4) for storage and further distribution. Three sets are identified: set 1 comprises tissues for which collection can be standardized and for which representative aliquots can be easily distributed (liver, spleen, lung, heart, fat depot, skin, muscle, and peripheral blood mononuclear cells); set 2 comprises tissues requiring special protocols because of their cellular heterogeneity (brain, digestive tract, secretory organs, gonads and gametes, reproductive tract, immune tissues, cartilage); set 3 comprises specific cell preparations (immune cells, tracheal epithelial cells). Dedicated sampling protocols were established and uploaded in https://data.faang.org/protocol/samples. Specificities between mammals and chicken are described when relevant. A total of 73 different tissues or tissue sections were collected, and 21 are common to the four species. Having a common set of tissues will facilitate the transfer of knowledge within and between species and will contribute to decrease animal experimentation. Combining data on the same samples will facilitate data integration. Quality control was performed on some tissues with RNA extraction and RNA quality control. More than 5,000 samples have been stored with unique identifiers, and more than 4,000 were uploaded onto the Biosamples database, provided that standard ontologies were available to describe the sample. Many tissues have already been used to implement FAANG assays, with published results. All samples are available without restriction for further assays. The requesting procedure is described. Members of FAANG are encouraged to apply a range of molecular assays to characterize the functional status of collected samples and share their results, in line with the FAIR (Findable, Accessible, Interoperable, and Reusable) data principles

Valorization and properties of landfill leachates humic substances

Des expérimentations ont été menées au laboratoire, avec des substances humiques (SH) extraites de lixiviats de Centre d’Enfouissement Technique et une formulation stable de SH (12 % d’acides humiques et 3% d’acides fulviques) commercialisée par la firme TRADECORP s.a. (Espagne) sous l’appellation « Humifirst », en vue d’en étudier leurs effets sur le développement du système racinaire de vitroplants de bouleau et d’aulne en absences d’interférences. Les résultats obtenus montrent qu‘un traitement à faible concentration (10 ppm) pendant la phase d’induction/initiation peut se révéler légèrement défavorable à la formation de racines chez l’aulne mais pas chez le bouleau, tandis qu’en phase d’élongation racinaire, il y a augmentation du nombre de racines par plantule uniquement chez le bouleau. A 100 ppm de SH de lixiviats en phase d’élongation, il y a inhibition totale de l’enracinement chez l’aulne et réduction de la densité des racines latérales chez le bouleau. Dans ces conditions, les pousses de bouleau croissent pourtant davantage. Ces observations se distinguent de celles d’Humifirst qui n’a pas d’effet significatif et pas d’inhibition. Les effets directs des substances humiques de lixiviats sur le développement racinaire et celui des plantules varient d’une espèce végétale à l’autre en fonction de la concentration.Experiments were conducted in the laboratory with humic substances (HS) extracted from Landfill leachate and stable HS formulation called "Humifirst" (12% humic acid 3% and fulvic acid) from TRADECORP company's (Spain), in order to study their effects on root system development of birch and alder vitroplants in absence of interferences. The results obtained show that treatment with a low concentration (10 ppm) during induction/initiation phase may be slightly unfavorable to the formation of roots in alder but not in birch. While, in root elongation phase, there is an increase in the number of roots per shoot only in birch. Applied at 100 ppm during elongation phase, leachate HS inhibit completely rooting in alder and reduce lateral root density in birch. Under these conditions, the birch shoots grow yet more. These observations differ from those of Humifirst, which has no significant effect and no inhibition. The direct effects of leachate HS on root development and shoot growth vary from one species to another depending on the concentration

Biodegradation of Polycyclic Aromatic Hydrocarbons in Mangrove Sediments Under Different Strategies: Natural Attenuation, Biostimulation, and Bioaugmentation with Rhodococcus erythropolis T902.1

Polycyclic aromatic hydrocarbons (PAHs) are pollutants that occur in mangrove sediments. Their removal by bacteria often depends on specific characteristics as the number of benzene rings they possess and their solubility. Their removal also depends on environmental factors, such as pH, temperature, oxygen, and the ability of the endogenous or exogenous microflora to metabolize hydrocarbons.With the aim of treating mangrove sediments polluted by hydrocarbons in a biological way, a biodegradation experiment was conducted using mangrove sediments artificially contaminated with a mixture of four PAHs. The study used Rhodococcus erythropolis as an exogenous bacterial strain in order to assess the biodegradation of the PAH mixture by natural attenuation, biostimulation, bioaugmentation, and a combination of biostimulation and bioaugmentation. The results showed that the last three treatments were more efficient than natural attenuation. The biostimulation/bioaugmentation combination proved to be the most effective PAH degradation treatment

Characterization and Evaluation of the Potential of a Diesel-Degrading Bacterial Consortium Isolated from Fresh Mangrove Sediment

Hydrocarbons are ubiquitous and persistent organic pollutants in the environment. In wetlands and marine environments, particularly in mangrove ecosystems, their increase and significant accumulation result from human activities such as oil and gas exploration and exploitation operations. Remediation of these ecosystems requires the development of adequate and effective strategies. Natural attenuation, biostimulation, and bioaugmentation are all biological soil treatment techniques that can be adapted to mangroves. Our experiments were performed on samples of fresh mangrove sediments from the Cameroon estuary and mainly from the Wouri River in Cameroon. This study aims to assess the degradation potential of a bacterial consortium isolated from mangrove sediment. The principle of our bioremediation experiments is based on a series of tests designed to evaluate the potential of an active indigenous microflora and three exogenous pure strains, to degrade diesel with/without adding nutrients. The experiments were conducted in laboratory flasks and a greenhouse in microcosms. In one case, as in the other, the endogenous microflora showed that it was able to degrade diesel. Under stress of the pollutant, the endogenous microflora fits well enough in the middle to enable metabolism of the pollutant. However, the Rhodococcus strain was more effective over time. The degradation rate was 77 and 90%in the vials containing the sterile sediments and non-sterile sediments, respectively. The results are comparable with those obtained in the microcosms in a greenhouse where only the endogenous microflora were used. The results of this study show that mangrove sediment contains an active microflora that can metabolize diesel. Indigenous and active microflora show an interesting potential for diesel degradation

FRACTURES OUVERTES DE JAMBE REVUE DES CAS DE 1977 A 1978

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Recherches de lignées aromatiques d’Abies par hybridation somatique

L’objectif du projet de recherche est d’associer les caractéristiques de croissance d’A. nordmanniana aux propriétés aromatiques d’autres espèces d’Abies en suivant la voie de la fusion somatique. Les travaux de recherche en culture "in vitro" sont menés au laboratoire de l’Unité de Génie biologique du Département "Science du Vivant" du CRAW (section 1) tandis que les analyses relatives à la détermination des profils aromatiques sont réalisées dans le laboratoire de l'Unité chimie générale et organique de l'Université de Liège-Gembloux Agro- Bio-Tech (section 2). Les deux Unités de recherche ont poursuivi leurs activités en parfaite collaboration. La première a tenté de restituer ou garder les propriétés embryogènes au travers de protoplastes provenant de lignées embryogènes d’A. nordmanniana, d’induire l’embryogenèse somatique sur des tissus d’embryons zygotiques d’autres Abies aromatiques et de réaliser des fusions somatiques en associant des protoplastes à des cellules de têtes d’embryons. La seconde s’occupait de caractériser les composés aromatiques, de suivre leur évolution selon période de végétation, de distinguer les espèces entre elles selon le profil aromatique de leurs graines tandis qu’en parallèle, elle mettait au point les techniques d’analyses en conditions aseptiques sur des lignées embryogènes d’A. nordmanniana d’origines génétiques différentes et sur les masses issues de fusions potentielles intra ou interspécifiques avec A. balsamea.Recherches de lignées aromatiques d’Abies par hybridation somatique - aspects aromatiques (D31-1301 - section 2

Effect of humic substances on in vitro rooting of alder (Alnus glutinosa (L.) Gaertn) and birch (Betula pendula Roth)

Humic substances (HS) are organic compounds resulting from the physical, chemical and microbiological transformations of organic residues. Present everywhere in the nature; they are taking part in basic functionalities in any ecosystems involving soils, sediments, water and landfills. They are heterogeneous and complex carbon macromolecules. Our study aims to compare the effect of HS from différent sources on in vitro rooting of woody plants

The Effect of Nutrients on the Degradation of Hydrocarbons in Mangrove Ecosystems by Microorganisms

peer reviewedMangrove ecosystems are areas prone to various types of pollution, especially hydrocarbons. These hydrocarbons mostly stem from human activities such as spills coming from offshore oil operations, runoff from surrounding urban areas or atmospheric deposition. This pollution causes the decline of mangroves, which results in an imbalance in the functioning of this particular ecosystem with damages to the microbiota. Biodegradation allows to restore these ecosystems. This biodegradation can only be effective in specific environmental conditions. The presence of nutrients, which stimulate bacterial growth and promote biodegradation, is a key parameter to be considered. During this experiment, we achieved biodegradation tests to assess the effect of nitrogen and phosphorus on the process. The results showed that the biodegradation rates were strongly bound to the presence of nutrients. The degradation rates depended on the medium. The treatment that reached the best rate of degradation of diesel after 10 days was the one using 20% of a nutrient solution (MSM) containing nitrogen and phosphorus. This treatment led to a maximal degradation of 84.7% ± 4.7% obtained in the flasks containing 20% of a nutrient solution (MSM) containing nitrogen and phosphorus