Plant growth promoting rhizobacteria: Beneficial effects for healthy and sustainable agriculture

It is unanimously admitted that the chemical fertilizers and pesticides used in modern agriculture create a real environmental and public health problems. One of the promising solutions to substitute these agrochemicals products is the use of bio-resources, including plant growth promoting rhizobacteria (PGPR). The PGPR focused more and more scientific attention in recent decades. These rhizospheric bacteria colonize actively the root system of plants and improve their growth and yield. The PGPR use different mechanisms of action to promote plant growth. These mechanisms were grouped into three clusters according to the PGPR effects on plant physiology. These groups are as follow: (i) biofertilization including biological fixation of atmospheric nitrogen, phosphate solubilization, siderophores production and exopolysaccharides production; (ii) phytostimulation including production of indole acetic acid, gibberellins, cytokinins and ethylene; and (ii) biocontrol including induction of systemic resistance, competition for iron, nutrient and space, production of antibiotics, lytic enzymes, hydrogen cyanide and volatile compounds. In view of the latest advances in PGPR biotechnology, this paper proposes to do the review on PGPR in rhizosphere and describes the different mechanisms used by PGPR to promote the plants growth and health. In prospect to a healthy and sustainable agriculture, respectful of environment, the PGPR approach revealed as one of the best alternatives.Keywords: Rhizosphere, plant growth promoting rhizobacteria (PGPR), root colonization, biofertilization, biocontrol, biostimulation, interaction plant-microorganisms, sustainable agricultur

Essai d’isolement de Campylobacter dans la viande de volaille en République du Bénin

La viande de volaille importée occupe une place importante dans l’alimentation béninoise. Elle est le plus souvent mise en cause dans les cas de toxi-infections alimentaires. De ce fait, elle devrait être sujette à uncontrôle de tous les microorganismes de toxi-infections afin de préserver la santé des consommateurs. Mais il s’avère que Campylobacter, qui de plus en plus est indexé, ne fait pas partie de la gamme des bactériesrecherchées pour la qualification sanitaire des aliments au Bénin. Cette situation serait due aux probables difficultés liées à l’isolement de ce germe. La présente étude a essayé d’isoler par culture cette bactérie afin de prouver que sa recherche en microbiologie alimentaire est possible. Cela pourrait permettre de commencer par l’inclure dans les diagnostics ultérieurs. Pour ce faire, 30 échantillons de viande de volaille importée ont fait l’objet d’analyse au Laboratoire de Microbiologie du Ministère de la Santé. Sur les 30 échantillons, Campylobacter a été isolé dans 6, soit un taux de contamination de 20%. En somme, Campylobacter peut être isolé par culture dans notre contexte.Mots clés : Campylobacter, viande de volaille, maladies alimentaires, Bénin.

PHYTOCHEMISTRY AND BIOLOGICAL ACTIVITIES OF CRATEVA ADANSONII EXTRACTS

Objective: This study aims to search the secondary metabolites of Crateva adansonii (leaves and bark) and evaluate some biological activities (antimicrobial, antioxidant and cytotoxicity's property) of these extracts.Methods: The phytochemical screening was made with standard method. Agar diffusion method was used for antibacterial activity coupled with Minimum Inhibitory Concentration (MIC) and Bactericidal (MBC) determination. The antifungal test was performed by the mycelial development reduction method. DPPH method was used to evaluate the extracts antioxidant activity. Artemia salina larvae were use as support to evaluate the toxicity of the extracts.Results: The results of the phytochemical screening reveal the presence of polyphenols, triterpenoids, and glycosides in the both organs (leaves and bark) of C. adansonii. All the extracts have low activity on the reference strains with a larger diameter of 17±00 mm (S. oralis). Only the ethanolic and hydroethanolic leaf's extracts inhibited respectively 20% and 10%, of the clinical strain S. aureus. The ethyl acetate leaf's extract shows the best antifungal activity (89,19%) with A. clavatus. All extracts present dose-dependent antiradical properties and are non-toxic for the cells of Artemia salina. C. adansonii bark extracts had the best reducing power (23,80±0, 137 mmol/g EqAA EAA) of the DPPH radical.Conclusion: C. adansonii is therefore an active principle source for the development of drugs to antimicrobial and antioxidant activitie

State of the Art and Contribution to the Documentation on Fishing, Aquaculture and on the Microbiological Profile of Clarias gariepinus and Oreochromis niloticus Two Species of Fish Reared in the Whedos of the Upper Ouémé Delta in the Republic of Benin

Fish is an important source of animal protein in Africa and is used in the composition of several national dishes. This literature review examines fishing, aquaculture and fish reared in the whèdos of the upper Ouémé delta in Benin. It addresses socio-economic aspects, nutritional importance and traditional fish preservation technology. The sources of information used are publications, books, reports of dissertations and theses and technical notes. It was found that Clarias gariepinus and Oreochromis niloticus, among others, are two species of fish most often raised in the whèdos of the Ouémé River in Benin.  These fish adapt to large variations of ecological factors of the aquatic environment found everywhere in Africa and reproduce easily in captivity, which favors their breeding in ponds. These species present multiple fish farming qualities: resistance to high densities, resistance to diseases and low oxygen levels, easy adaptation to artificial feeding and high growth. Microbiological contamination of fish flesh occurs only after capture and can be endogenous or exogenous contamination. Generally, several processes are used to overcome this problem of contamination of fish. Hot smoking and drying are very often used. The lack of hygiene in the traditional technology of smoking fish sometimes favor a considerable microbial contamination of the obtained products. Thus, contaminated fish can be the cause of foodborne diseases such as food poisoning. Most of the pathogenic strains responsible for these diseases are resistant to certain antibiotics

State of the Art and Contribution to the Documentation on Fishing, Aquaculture and on the Microbiological Profile of Clarias gariepinus and Oreochromis niloticus Two Species of Fish Reared in the Whedos of the Upper Ouémé Delta in the Republic of Benin

Fish is an important source of animal protein in Africa and is used in the composition of several national dishes. This literature review examines fishing, aquaculture and fish reared in the whèdos of the upper Ouémé delta in Benin. It addresses socio-economic aspects, nutritional importance and traditional fish preservation technology. The sources of information used are publications, books, reports of dissertations and theses and technical notes. It was found that Clarias gariepinus and Oreochromis niloticus, among others, are two species of fish most often raised in the whèdos of the Ouémé River in Benin.  These fish adapt to large variations of ecological factors of the aquatic environment found everywhere in Africa and reproduce easily in captivity, which favors their breeding in ponds. These species present multiple fish farming qualities: resistance to high densities, resistance to diseases and low oxygen levels, easy adaptation to artificial feeding and high growth. Microbiological contamination of fish flesh occurs only after capture and can be endogenous or exogenous contamination. Generally, several processes are used to overcome this problem of contamination of fish. Hot smoking and drying are very often used. The lack of hygiene in the traditional technology of smoking fish sometimes favor a considerable microbial contamination of the obtained products. Thus, contaminated fish can be the cause of foodborne diseases such as food poisoning. Most of the pathogenic strains responsible for these diseases are resistant to certain antibiotics

State of the Art and Contribution to the Documentation on Fishing, Aquaculture and on the Microbiological Profile of Clarias Gariepinus and Oreochromis Niloticus Two Species of Fish Reared in the Whedos of the Upper Ouémé Delta in the Republic of Benin

Fish is an important source of animal protein in Africa and is used in the composition of several national dishes. This literature review examines fishing, aquaculture and fish reared in the whèdos of the upper Ouémé delta in Benin. It addresses socio-economic aspects, nutritional importance and traditional fish preservation technology. The sources of information used are publications, books, reports of dissertations and theses and technical notes. It was found that Clarias gariepinus and Oreochromis niloticus, among others, are two species of fish most often raised in the whèdos of the Ouémé River in Benin. These fish adapt to large variations of ecological factors of the aquatic environment found everywhere in Africa and reproduce easily in captivity, which favors their breeding in ponds. These species present multiple fish farming qualities: resistance to high densities, resistance to diseases and low oxygen levels, easy adaptation to artificial feeding and high growth. Microbiological contamination of fish flesh occurs only after capture and can be endogenous or exogenous contamination. Generally, several processes are used to overcome this problem of contamination of fish. Hot smoking and drying are very often used. The lack of hygiene in the traditional technology of smoking fish sometimes favor a considerable microbial contamination of the obtained products. Thus, contaminated fish can be the cause of foodborne diseases such as food poisoning. Most of the pathogenic strains responsible for these diseases are resistant to certain antibiotics

Prévalence et rôle des lipides dans l’avènement de l’obésité au Bénin

Le recueil des mesures anthropométriques des étudiants de l’Institut National Médico-Social (INMES) au Bénin nous a permis de calculer l’Indice de Masse Corporelle de cette population, seul indicateur pour évaluer l’état nutritionnel des adultes de point de vue énergétique. Au terme de cette évaluation, il ressort que la prévalence de l’obésité est plus élevée chez les femmes (9,81%) que chez les hommes (0,8%). L’indice de Masse Corporelle (IMC) médian est estimé à 23,03 chez les femmes contre 21,45 chez les hommes. Pour savoir les causes éventuelles de l’obésité, nous avons prélevé le sang de 41 étudiants supposés obèses et 92 ensurpoids et avons dosé les paramètres biologiques comme Cholestérol Total, Cholestérol-HDL, Cholestérol-LDL et Triglycérides. Il ressort de cette étude que, sur les quatre (04) composants lipidiques dosés, seul letaux de cholestérol-LDL est élevé au sein de cette population avec une valeur médiane de 1,52 g/l. Aussi, nous constatons une disparité dans les paramètres dosés. Par ailleurs, presque le quart (25%) des individus ensurpoids ou obèses ont une lipidémie normale. D’après nos résultats, c’est le métabolisme de Cholestérol-LDL qui est perturbé et que l’état d’obésité serait lié à d’autres facteurs tels que génétiques, hormonaux et autres

L’avenir des dispositifs d’éducation non formelle

Chaque pays doit identifier son « réseau d’apprentissage », car le système éducatif ne se réduit pas à la « forme scolaire ». Outre l’éducation formelle, il comprend l’éducation non formelle et informelle. En Afrique francophone tout particulièrement (mais pas seulement), l’éducation non formelle est indispensable, face aux insuffisances du système formel tant en efficacité interne qu’externe. Il s’agit donc de revoir l’architecture du système éducatif, en passant du paradigme de la scolarisation obligatoire au droit à l’apprentissage tout au long de la vie.Each country must identify its “learning network” because the education system is not limited to “school”. Besides formal education, it includes non-formal and informal education. In French-speaking Africa in particular (but not exclusively), non-formal education is essential in the face of the inadequacies of the formal system, both in terms of internal and external efficiency. It is therefore a matter of reviewing the architecture of the education system, moving from the paradigm of compulsory schooling to the right to lifelong learning.Cada país debe identificar su “red de aprendizaje”, ya que el sistema educativo no se reduce a la “forma escolar”. Aparte de la educación formal, abarca también la educación no formal y la educación informal. En África francófona en particular –pero no solamente– la educación no formal es imprescindible frente a las insuficiencias del sistema formal tanto en eficacidad interna como externa. Se trata pues de revisar la arquitectura del sistema educativo, pasando del paradigma de la escolarización obligatoria al derecho al aprendizaje a lo largo de la vida

ANTIMICROBIAL, ANTIOXIDANT, CYTOTOXIC ACTIVITIES AND PHYTOCHEMICAL ASSESSMENT OF COLA ACUMINATA USED IN BENIN

Objective: The aim of this study was to make a phytochemical screening and measure some biological activities of Cola acuminata's seeds and leaves extracts.Methods: The secondary metabolite was detected by the method based on coloring and precipitation differential reactions. The antibacterial and antifungal activities were assessed in vitro by the macrodillution and solid medium agar diffusion method. 2,2-diphényl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods were used to evaluate the antioxidant activity of the tested extracts of which larval cytotoxicity was studied.Results: Our data revealed that the seeds contain more polyphenols than the leaves. The seeds extracts displayed a good antibacterial activity against both reference strains and food Staphylococcus strains. The inhibition diameters varied from 7±2.82 to 21.5±4.94 mm. The smallest Minimum Inhibitory Concentrations (MIC) on the food strains (0.08 mg/ml) is twice less than the reference strains one (0.15 mg/ml), this observation is contrary to the Minimum Bactericidal concentrations (MBC). Susceptibility of fungal strains varies according to the extracts (p = 0.0016). The seeds ethyl acetate extracts had the best antioxidant activity with DPPH and ABTS methods. The Lethal Doses (LD50) showed that no extract was toxic.Conclusion: Cola acuminata seeds are richer than the leaves in compounds with biological activities. These two organs have interesting antimicrobial, antifungal and antioxidant activity variables depending to the extracts. The seeds have better biological activity than the leaves.Â

Mold Occurrence in Fresh Chilli Pepper (Capsicum spp.) Harvested Directly in the Field in Benin Republic

Introduction: The chilli pepper (Capsicum spp.), ranked among the world's leading spices or food additives, is now Benin'ssecond most-important vegetable crop after tomatoes. Unfortunately, chilli peppers are likely to be contaminated with mold which produces dangerous mycotoxins due to cultural practices, transport, and post-harvest storage. Objective: The purpose of this study is to isolate and identify the molds that contaminate chilli pepper varieties in open fields according to the cultivation methods used in the Republic of Benin. Materials and Methods: A total of 240 samples of three varieties of chilli peppers were taken directly from six districts of Benin. The molds were isolated and purified on a PDA (Potato Dextrose Agar) medium for identification. The identification focused on the morphological and cultural characteristics of isolated strains. Results: Nine (9) fungal genera from different taxonomic groups were detected. The genera that have been represented are Aspergillus (34%), Fusarium (21%), Penicillium (16%), Alternaria (7%), Cladosporium (7%), Mucor (7%), Scytalidium (4%), Trichophyton (3%), and Rhizopus(1%). Conclusion: The present study shows that chilli pepper is being contaminated in Benin. The genera Aspergillus, Fusarium, Penicillium, and Alternaria are respectively the main toxinogenic molds that contaminate peppers in the field. The mold control in chilli pepper against pathogenic agents became urgently required to reduce a consumer disease caused by chilli pepper in Benin