Antimycotoxigenic and antifungal activities of Citrullus colocynthis seeds against Aspergillus flavus and Aspergillus ochraceus contaminating wheat stored

Plant extracts and their constituents have a long history as antifungal agents, but their use in biotechnology as preservatives, due to the increasing resistance of fungi to fungicides, has been rarely reported. The aim of this study was to assess in vitro antifungal and antimycotoxigenic power of methanolic and aqueous extracts of Citrullus colocynthis seeds, an aromatic and medicinal plant, of Algerian flora, against two toxigenic species of the genera Aspergillus responsible of contamination of wheat stored. The antifungal and antimycotoxigenic activity of methanolic and aqueous extracts were screened against Aspergillus ochraceus and Aspergillus flavus. Dillution method was used to investigate the antimicrobial and antimycotoxigenic activity. These bioassays are preceded by a phytochemical screening. The phytochemical analysis of seeds extracts revealed the presence of some chemical groups (polyphenols, steroids and alkaloids) which can express the desired activities. The results suggest that the extracts showed a very good antifungal activity against A. ochraceus, but for A. flavus any antifungal activity was recorded. The extracts have good antiochratoxigenic power in liquid medium. This evaluation confirms that the extracts of C. colocynthis seeds used at low concentration may have significant potential for biological control of fungi and theirs toxins.Keywords: Citrullus colocynthis, methanolic extract, aqueous extract, phytochemical screening, antifungal activity, antimycotoxigenic activity, antiochratoxigenic activity

Toxicology, biosynthesis, bio-control of aflatoxin and new methods of detection

Mycotoxins and their derivatives since their discoveries and until the present time are behind unspecified economic and medical damages. Aflatoxins are classified according to their physical–chemical and toxicological characters in the most dangerous row of the mycotoxins. These aflatoxins are in part responsible, of irreversible medical disasters that are not easily manageable such as cancer of the liver and kidneys, and in the other part, of losses in the stored cereal products. Based on these crucial findings, monitoring of this toxin became imperative in post-harvest food products, during storage, during transformation chain and even during the long phases of conservation. Vigilance of this toxin is delivered by detection methods using very advanced technologies to respond in the shortest possible times. In addition, the knowledge of factors supporting the biosynthesis of aflatoxins such as the temperature, moisture content, concentration of nitrogen and carbon, and the molecules responsible for the genetic control of the synthesis will be reflected later in the choice of bio-control techniques. This control is currently based on new strategies using the bioactives substances of the plants, the lactic bacteria and some strains of actinomycetes that have good inhibiting activity against aflatoxins with fewer side effects on Man. On the other hand, this brief review summarizes the results of new studies demonstrating the toxicity of the toxin, new detection methods and bio-control

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RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF

An ethnopharmacological survey of plants used in traditional diabetes treatment in south-eastern Algeria (Ouargla province)

International audienceAn ethnopharmacological survey was performed in the Ouargla region (northeast of Algerian Sahara) to document ethnomedicinal knowledge and to catalogue the medicinal plants used to treat diabetes mellitus. We conducted in-person interviews of 289 diabetic patients, 25 herbalists and 10 healers in eight different areas of the Ouargla region. The results indicate that phytotherapy was always practiced to treat disease (60.90%), especially diabetes. Among the type 2 diabetes interviewees, 58 patients (44.27%) used only medicinal plants. Seventy-nine percent of plant users (176) were satisfied with herbal medicine i.e. 74% of the men and only 45.90% of the women. This could be explained by a high education level for the women. A total of 67 plant species that belong to 32 families were mentioned and were used to prepare 130 different formulations for treating diabetes and foot ulcers. Among the 13 most frequently cited species, only 3 were cultivated. More than 34 of the species are wild septentrional Sahara species. Thirteen species (19.40%) are endemic; three of them are reported for the first time as hypoglycaemic plants: Matricaria pubescens, Oudneya africana and Rhanterium adpressum. For nine species, we could not locate experimental data on anti-diabetic activity. Sixty six species are used to treat diabetes, while fifty one are used to treat symptoms that might be related to diabetes (especially foot ulcers). Anvillea radiata, Ammodaucus leucotrichus, Artemisia herba-alba and Citrullus colocynthis have the highest values of relative frequency citation (RFC), informant consensus factor (Fic) and use value (UV). They are the most used plant to decrease level of blood glucose and to treat foot ulcer. The new endemic plant species highlighted in the study could reveal an interest for further phytochemical and pharmacological studie

Structure and composition of the wax of the date palm, Phoenixdactylifera L., from the septentrional Sahara

International audienceThe date palm, Phoenix dactylifera L. is an important economic species in arid regions of the septentrional Sahara. As this species survives under drastic conditions, the waxes of the leaf, as a strategy in response to stress, were the focus of these studies. From a structural point of view, the cuticle is overlaid with crys-talloid waxes corresponding to epicuticular wax. The majority of these waxes were polygonal rodletsforming rings around the stomata, corresponding to the ‘Strelitzia Type’. The effects of intense erosion were observed on the oldest leaves. From a chemical aspect, the wax primarily comprised n-alkanes(65.0% of the total wax), the most abundant of which is n-hentriacontane (24.3% of the n-alkanes). In the polar fraction, the triterpenoids represented the highest percent (19.6% of the total wax). The widely distributed ursolic acid and betulin were the most important triterpenoids identified, and the two othercompounds were sterols. Betulin is an uncommon triterpenoid. According to previous studies, we hypoth-esized that the two main classes, n-alkanes and triterpenoids, are involved in formation of the rodlet wax structure. Fatty acids, aliphatic alcohols and ketones were also identified. A homologous series ofaliphatics were describe

Effet de la pollution atmosphérique par les hydrocarbures sur le lichen Xanthoria parietina (L.) Th (Teloschistaceae) dans la zone de Hassi Messaoud (Sahara septentrional algérien

International audienceThis work is focused on bio-detection air pollution by hydrocarbons in the area of Hassi Messaoud Ouargla region (Northern Sahara Algerian East). Lichens collected on their support in the northeast of Algeria (Annaba), are used as a biological model to assess the effects of this pollution transplantation for 75 days. The levels of soluble compounds in hexane (CSH) at the lichen transplants increase and then decrease during the exposure time. With respect to the chlorophyll content, it decreases as the sampling period. The changes observed over time could have originated two causes of air pollution on the one hand and dehydration thalli under the effect of the temperature of the other areas.Le présent travail porte sur la bio-détection de la pollution atmosphérique par les hydrocarbures dans la zone de Hassi Messaoud située dans la région de Ouargla (Sahara septentrional Est algérien). Les lichens prélevés sur leur support dans le nord-est de l’Algérie (Annaba), sont utilisés comme modèle biologique pour évaluer les effets de cette pollution par transplantation pendant 75 jours. Les teneurs en composés solubles dans l’hexane (CSH) au niveau des transplants lichéniques augmentent puis diminuent au cours du temps d’exposition. La teneur en chlorophylle diminue en fonction de la période d'échantillonnage. Les modifications observées au cours du temps pourraient avoir pour origine deux causes, la pollution atmosphérique d’une part et la déshydratation des thalles sous l’effet de la température du milieu d’autre part

RNAi-based system a new tool for insects’ control

One of the molecular devices practised recently has been the fusion of RNA interference (RNAi) into some agricultural products. It is a definite genetic controlling system recognized in eukaryotes. Through this system, certain exogenous pathogens are neutralized by deactivating the expression of target genes. The decisive factor for the progress of this gene defence machinery is the double-stranded RNA (dsRNA). The effectiveness and specificity of the RNAi tool in gene silencing have been approved with great precision in small-scale guide tests. The development of this molecular tool as bioinsecticides has started to attract the biotechnology industries. Once the safety and certainty actions respecting the regulatory framework are established by researchers and biotechnology industries for crop protection, for example, sustainability and particularity of defence, develop new resistant cultivars against plant pests, and removal of all unexpected effects on the environment, genetically modified crops incorporating dsRNA can be marketed. The current chapter discusses the RNAi tool and its role in protecting crops from insect pest attacks, dsRNA transfer methods in plant cells, and critical points affecting the achievement of the molecular tool. Finally, some environmental risks identified in the small-scale guide tests are discussed

Petroleum degradation by endophytic Streptomyces spp. isolated from plants grown in contaminated soil of southern Algeria

Petroleum hydrocarbons are well known by their high toxicity and recalcitrant properties. Their increasing utilization around worldwide led to environmental contamination. Phytoremediation using plant-associated microbe is an interesting approach for petroleum degradation and actinobacteria have a great potential for that. For this purpose, our study aimed to isolate, characterize, and assess the ability of endophytic actinobacteria to degrade crude petroleum, as well as to produce plant growth promoting traits. Seventeen endophytic actinobacteria were isolated from roots of plants grown naturally in sandy contaminated soil. Among them, six isolates were selected on the basis of their tolerance to petroleum on solid minimal medium and characterized by 16S rDNA gene sequencing. All petroleum-tolerant isolates belonged to the Streptomyces genus. Determination by crude oil degradation by gas chromatorgraph-flame ionization detector revealed that five strains could use petroleum as sole carbon and energy source and the petroleum removal achieved up to 98% after 7 days of incubation. These isolates displayed an important role in the degradation of the n-alkanes (C6-C30), aromatic and polycyclic aromatic hydrocarbons. All strains showed a wide range of plant growth promoting features such as siderophores, phosphate solubilization, 1-aminocyclopropane-1-carboxylate deaminase, nitrogen fixation and indole-3-acetic acid production as well as biosurfactant production. This is the first study highlighting the petroleum degradation ability and plant growth promoting attributes of endophytic Streptomyces. The finding suggests that the endophytic actinobacteria isolated are promising candidates for improving phytoremediation efficiency of petroleum contaminated soil.Fil: Baoune, Hafida. No especifíca;Fil: Ould El Hadj-Khelil, Aminata. No especifíca;Fil: Pucci, Graciela. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Sineli, Pedro Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Loucif, Lotfi. No especifíca;Fil: Polti, Marta Alejandra. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentin

Bioremediation of petroleum-contaminated soils using Streptomyces sp. Hlh1

Purpose Bioremediation using microorganisms is a promising strategy to remediate soil with petroleum hydrocarbons.Streptomycessp. Hlh1, an endophytic strain, has previously demonstrated the ability to degrade crude petroleum in liquid culture.To apply this strain at field scale, it is necessary to test its ability to colonize the soil, compete with native microbiota, and removethe petroleum hydrocarbons under unfavorable conditions. Herein, a study was conducted to evaluate the performance ofStreptomyces sp. Hlh1 to remove crude petroleum from contaminated sterilized and non-sterilized soils.Materials and methods Soils samples, contaminated with 2%, 5%, and 10% of petroleum, were inoculated with Streptomycessp.Hlh1, and incubated at 30 °C for 4 weeks. At the end of bioremediation assays, the pollutant concentrations were determined byGas chromatography flame ionization detector and the degradation rates were also calculated. The survival of the strain in the soilwas estimated and the toxicity of metabolites was evaluated on Lactuca sativa.Results and discussion Streptomyces sp. Hlh1 was able to grow and remove total petroleum hydrocarbons (TPH), n-alkanes, andaromatic hydrocarbons found in soil samples. In sterilized soil samples, Streptomyces sp. Hlh1 removed up to 40% of TPH at aninitial concentration of 10%. Whereas, the maximum TPH removal reached was 55% in non-sterilized soil at an initial concentration of 2%. In addition, it was observed that the degradation of aromatic hydrocarbons was more active than n-alkanes. Thestrain grew well and produced high biomass in contaminated soil. Lettuce seedling was found to be the adequate bioindicator toassess the toxicity of petroleum end products. Streptomyces sp. Hlh1 performed a successful bioremediation, which was confirmed through the phytotoxicity test.Conclusions The study shows the first insight of the contribution of free endophytic actinobacterial strain in the bioremediation ofpetroleum-contaminated soil; therefore, it suggests that Streptomyces sp. Hl1 can be usefully exploited at field scale.Fil: Baoune, Hafida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Université Kasdi Merbah Ouragla; ArgeliaFil: Aparicio, Juan Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Pucci, Graciela. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Ould El Hadj-Khelil, Aminata. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Université Kasdi Merbah Ouragla; ArgeliaFil: Polti, Marta Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentin

Genetic characterisation of carbapenem-resistant Gram-negative bacteria isolated from the University Hospital Mohamed Boudiaf in Ouargla, southern Algeria

International audienceObjectives: The aim of this study was to investigate the molecular epidemiology and the genetic support of carbapenem-resistant Enterobacteriaceae and Acinetobacter spp. isolates collected in the University Hospital of Ouargla, southern Algeria. Methods: A total of 99 Gram-negative bacteria (GNB) were collected from stool samples of colonised patients and from inanimate surfaces in the hospital environment between December 2014 and August 2015. Selected Enterobacteriaceae and Acinetobacter spp. isolates with reduced susceptibility to carbapenems were subjected to phenotypic study, including antibiotic susceptibility testing according to CA-SFM-EUCAST 2015 guidelines and modified Carba NP test. Genes encoding carbapenemases, extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases were screened by PCR and sequencing. Clonal relatedness was determined by multilocus sequencing typing (MLST). Results: Of the 99 GNB isolates, 10 (10.1%) showed reduced susceptibility to carbapenems were studied further, including 7 Acinetobacter baumannii, 1 Acinetobacter nosocomialis, 1 Escherichia coli and 1 Klebsiella pneumoniae. PCR and sequencing showed that four A. baumannii isolates and the single A. nosocomialis isolate harboured blaNDM-1. In addition, blaOXA-23 was observed in three A. baumannii isolates, and blaOXA-48 was detected in the two Enterobacteriaceae isolates. MLST assigned the K. pneumoniae to ST999 and the E. coli to ST38. The seven A. baumannii isolates belonged to ST85 and ST2. Conclusions: This study describes the epidemiology of carbapenemases produced by Enterobacteriaceae and Acinetobacter spp. in southern Algeria and reports the first description of metallo-beta-lactamase NDM1-producing A. nosocomialis in Algeria. (C) 2016 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved