Physico-chemical characterization of the essential oil of Origanum majorana (L.) cultivated in a semi-arid bioclimatic stage (South-east Algeria)

The essential oils (EO) are complex volatile natural compounds,  characterized by a strong odor, produced by the plants as secondary metabolites. The composition of these last is strongly influenced by intrinsic factors twinned with the extrinsic factors such as technology, the cultivation techniques, the édapho-climatic conditions of the culture  medium, like those of the storage of vegetable drug, the techniques of treatment, etc… The extraction of essential oils (EO) of marjoram (O. majorana), by the method of hydro-distillation made it possible to obtain an average essential oil yield of about 0.61% of which the density is low. The chemical characterization by gas chromatography highlighted the wealth of this oil in Bornéol (15.50%) and Cineol (11.33%).Keywords: essential oil (EO); O. majorana L.; cineol; bornéol; Gas chromatography; secondary metabolite

Assessment of the effects of the control of grazing system in grazed arid steppic rangelands in Algeria

Face à la dégradation dont souffre la steppe en Algérie, la mise en repos, introduite récemment, représente un moyen efficace de contrôle et de gestion des écosystèmes pâturés des parcours steppiques arides de cette région. Trois sites ont été étudiés en vue d’évaluer dans chacun d’eux les effets de l’exclusion du pâturage suivie d’une gestion en pâturage contrôlé par rapport à un usage libre. La composition et la diversité floristique de la végétation, l’état de surface du sol et la qualité fourragère des espaces contrôlés, montrent une amélioration par rapport aux terrains pâturés librement. La nécessité d’un tel aménagement dans les parcours steppiques arides ainsi que la méthode d’échantillonnage dans ce genre d’évaluation sont discutéesFacing the degradation that the steppe in Algeria suffered, the grazing system using deferred grazing, introduced recently, is an effective means to control and manage the grazed ecosystems of steppic rangelands. Three sites have been studied to assess in each of them, the effects of the managed grazing on ecosystem in comparison to the free grazed ones. The composition and plant species diversity, surface soil conditions and forage quality in controlled areas, showed improvement compared with the freely grazed land. In the present work and usually regarding similar assessment tasks, conditions and sampling design are dictated by a request made much later after the grazing management set-up. The need of such a management in the arid rangelands and the sampling method are discusse

Physicochemical characteristics and pollen spectrum of some north-east Algerian honeys.

The qualities of seventeen honey samples harvested from the North-East areas of Algeria were evaluated by determining the pollen spectrum, pollen number quantity and physicochemical attributes. Pollen analysis can therefore be useful to determine the geographical and botanical origin of honeys. The following determinations were carried out: pH, density, acidity (free, lactone and total), moisture, electrical conductivity,  hydroxymethylfurfural, diastase activity, apparent sucrose, and proteins.The results obtained in the present study show the variability of chemical composition of the honey samples. It proved that nine natural honeys are of blossoming origin; suitable for consumption and that one (T5 conferred Bougous) can be used with fine dietetics, it is very rich in pollen which is regarded as protein source. The remainder, eight honeys, were not in conformity with the International Regulatory Standards, their sugar contents (Sucrose) and hydroxymethylfurfural exceeded the InternationalRegulatory Standards Review by the International Honey Commission, this was probably due to use of syrup for the over-feeding the bees during the spring. The sample Bouhachana (G1) had high water content (more than 20%), low density and electrical conductivity higher than 5 μS/cm, which makes it likely to undergo fermentation and degradation. Honeys of Guerguour (T1), Boutheldja (T2) and Bouhadjar (T3) had pH lower than the European standards concerning the quality control of the foodstuffs (exp. honey). These samples are fragile; so we cannot preserve them for a long period. The palynological analysis (qualitative and quantitative) of the harvested samples in the area, showed the absence of a honey obtained from only one melliferous plant. All honeys are polyfloral exits of theseveral plant species visited by the worker bees during their blossoming periods. Three families are the most represented in the groups of pollen of accompaniment (the secondary pollen ranged between 16-45%) and the pollen considered as rare (minor pollen 3-15%) in the counted total number of the pollen grains in 10 grams of honey. These forager honey families are: Myrtaceae presented by the Eucalyptus, Papilionaceae presented by Hedysarum coronarium which is a forager plant characterized by a very vast surface of development, and Rosaceae represented byorchard and forest species.The pollen grain number counted in honeys is very significant (between 80 000 and 24 832 000pollen grain), what makes it possible to classify the samples analyzed among the categories rich in pollen

Essais de régénération artificielle par semis de la subéraie de Numidie orientale.

La régénération naturelle du chêne-liège par semis, se heurte à de nombreux problèmes aussi bien biotiques qu'abiotiques. Des essais de semis «in situ» ont été effectués pour tester l'efficacité de certaines techniques, s'inspirant de travaux sur le changement de la morphologie du système racinaire de certaines essences forestières à enracinement pivotant. Les résultats obtenus sont concluants, à savoir : le crochetage du sol est primordial pour la réussite du semis direct de chêne-liège et qu'en son absence, la pré-germination des glands et, à un moindre titre, la décapitation du pivot, avant la mise en terre, peuvent s'avérer assez bénéfiques

Essais de régénération artificielle par semis de la subéraie de Numidie orientale.

International audienceLa régénération naturelle du chêne-liège par semis, se heurte à de nombreux problèmes aussi bien biotiques qu'abiotiques. Des essais de semis «in situ» ont été effectués pour tester l'efficacité de certaines techniques, s'inspirant de travaux sur le changement de la morphologie du système racinaire de certaines essences forestières à enracinement pivotant. Les résultats obtenus sont concluants, à savoir : le crochetage du sol est primordial pour la réussite du semis direct de chêne-liège et qu'en son absence, la pré-germination des glands et, à un moindre titre, la décapitation du pivot, avant la mise en terre, peuvent s'avérer assez bénéfiques

Contribution à l’étude microbiologique des eaux de l’oued Medjerda dans l’extrême Est Algérien : Souk Ahras

La Medjerda constitue l’un des plus importants oueds de l’Est algérien. Les analyses de la flore microbienne des eaux procurées de six stations pendant les périodes humides et sèches de l’année 2009 ont montré que la notion de saison a une influence certaine sur la concentration en germes. Malgré la forte charge en bactéries indicatrices de la  contamination fécale (germes totaux, coliformes fécaux, streptocoques fécaux et Clostridium sulfito-réducteurs), les germes pathogènes du genre Salmonella n'ont pas été détectés. L'existence éventuelle de ces germes à l'état viable mais non cultivable constituerait un risque particulier du fait que les bactéries survivant à cet état ne sont pas détectables par les  techniques de culture classique. Par ailleurs, les levures et les moisissures sont présentes dans tous les sites étudiés, ce qui rejoint nos conclusions concernant les germes précédemment étudiés. Nos résultats montrent une dégradation importante dans la qualité des eaux de l’oued Medjerda notamment dans les sites 3 (cité Zarouria) et 4 (cité hospitalière).Mots clés : Oued Medjerda – Eau – Environnement – Pollution - Qualité microbiologique.Medjerda is one of the most important oueds in eastern Algeria. During the late wet and dry periods of the year 2009, the microbiological water quality of six stations was studied and showed that the concept of season has some effects on increasing concentration of germs during the dry season compared to the wet season. Despite the heavy load of faecal indicator bacteria (Plate Count, fecal coliforms, faecal streptococci and sulphite-reducing Clostridium), pathogens of Salmonella genus were not detected. The probable existence of these organisms in a viable state but non- cultivable constitutes a particular risk because the bacteria surviving in this state are not detectable by conventional culture techniques. Moreover, the yeasts and molds are present in all sites which join our conclusions regarding the seeds previously studied. The results show a significant impairment of Medjerda water quality especially in sites 3(Zarouria street) and 4 (Hospital street).Keywords : Oued Medjerda – Water – Environment – Pollution - Microbiological quality

EVALUATION DES EFFETS DU CONTROLE DE PATURAGE DANS DES PARCOURS STEPPIQUES ARIDES EN ALGERIE

National audienceAssessment of the effects of the control of grazing system in grazed arid steppic rangelands in Algeria. Facing the degradation that the steppe in Algeria suffered, the grazing system using deferred grazing, introduced recently, is an effective means to control and manage the grazed ecosystems of steppic rangelands. Three sites have been studied to assess in each of them, the effects of the managed grazing on ecosystem in comparison to the free grazed ones. The composition and plant species diversity, surface soil conditions and forage quality in controlled areas, showed improvement compared with the freely grazed land. In the present work and usually regarding similar assessment tasks, conditions and sampling design are dictated by a request made much later after the grazing management set-up. The need of such a management in the arid rangelands and the sampling method are discussed

EVALUATION DES EFFETS DU CONTROLE DE PATURAGE DANS DES PARCOURS STEPPIQUES ARIDES EN ALGERIE

National audienceAssessment of the effects of the control of grazing system in grazed arid steppic rangelands in Algeria. Facing the degradation that the steppe in Algeria suffered, the grazing system using deferred grazing, introduced recently, is an effective means to control and manage the grazed ecosystems of steppic rangelands. Three sites have been studied to assess in each of them, the effects of the managed grazing on ecosystem in comparison to the free grazed ones. The composition and plant species diversity, surface soil conditions and forage quality in controlled areas, showed improvement compared with the freely grazed land. In the present work and usually regarding similar assessment tasks, conditions and sampling design are dictated by a request made much later after the grazing management set-up. The need of such a management in the arid rangelands and the sampling method are discussed

Physicochemical Characteristics And Pollen Spectrum Of Some North-East Algerian Honeys

The qualities of seventeen honey samples harvested from the North-East areas of Algeria were evaluated by determining the pollen spectrum, pollen number quantity and physicochemical attributes. Pollen analysis can therefore be useful to determine the geographical and botanical origin of honeys. The following determinations were carried out: pH, density, acidity (free, lactone and total), moisture, electrical conductivity, hydroxymethylfurfural, diastase activity, apparent sucrose, and proteins. The results obtained in the present study show the variability of chemical composition of the honey samples. It proved that nine natural honeys are of blossoming origin; suitable for consumption and that one (T5 conferred Bougous) can be used with fine dietetics, it is very rich in pollen which is regarded as protein source. The remainder, eight honeys, were not in conformity with the International Regulatory Standards, their sugar contents (Sucrose) and hydroxymethylfurfural exceeded the International Regulatory Standards Review by the International Honey Commission, this was probably due to use of syrup for the over-feeding the bees during the spring. The sample Bouhachana (G1) had high water content (more than 20%), low density and electrical conductivity higher than 5 µS/cm, which makes it likely to undergo fermentation and degradation. Honeys of Guerguour (T1), Boutheldja (T2) and Bouhadjar (T3) had pH lower than the European standards concerning the quality control of the foodstuffs (exp. honey). These samples are fragile; so we cannot preserve them for a long period. The palynological analysis (qualitative and quantitative) of the harvested samples in the area, showed the absence of a honey obtained from only one melliferous plant. All honeys are polyfloral exits of the several plant species visited by the worker bees during their blossoming periods. Three families are the most represented in the groups of pollen of accompaniment (the secondary pollen ranged between 16-45%) and the pollen considered as rare (minor pollen 3-15%) in the counted total number of the pollen grains in 10 grams of honey. These forager honey families are: Myrtaceae presented by the Eucalyptus, Papilionaceae presented by Hedysarum coronarium which is a forager plant characterized by a very vast surface of development, and Rosaceae represented by orchard and forest species.The pollen grain number counted in honeys is very significant (between 80 000 and 24 832 000pollen grain), what makes it possible to classify the samples analyzed among the categories rich in pollen

A case of false positive cardiac troponin I in CANOMAD syndrome.

International audienc