Phenotypic characters of yeasts isolated from kpete-kpete, a traditional starter of a Benin opaque sorghum beer

Opaque sorghum beers are the most consumed African alcoholic beverages. Tchoukoutou is one of the Benin opaque sorghum beers. Its fermentation process is carried out using a traditional starter called kpete-kpete. The present study characterized and identified the yeasts isolated from kpete-kpete. A total of 24 samples of kpete-kpete were collected from eight different commercial processing sites in Northern Benin. The mean values of the pH, titrable acidity, dry matter content and refractive index for all samples were respectively 3.58; 0.07% as lactic acid; 16.61% and 7.0. The mean counts of yeasts was 9.24 log cfu/ml. Based on their phenotypic characters and their assimilation profiles, 49 yeasts were isolated and found to belong to five genera with seven species. Seventy one percent (71%) of the isolates were identified as Saccharomyces cerevisiae.Key words: Sorghum beer, tchoukoutou, kpete-kpete, yeast, Saccharomyces cerevisiae

Variations of Wave Energy Power in Shoaling Zone of Benin Coastal Zone

Today, we observe at the population level, that the improvement in comfort is accompanied by an increase in the electrical energy required. The predicted exhaustion of fossil energy resources maintains some speculation. Their unequal geographical distribution justifies the energy dependence of Benin overlooked from outside. So it is urgent to explore the various sources of renewable energy available to Benin. In this work, using measurements made ​​by the Millennium Challenge Account (MCA-Benin) as part of the extension of the port of Cotonou, with Boussinesq equations (Peregrine) and Stokes waves dispersion relation, we characterized the variations of various swell parameters (height, wavelength, velocities) in the shoaling zone on the study site and proceeded to estimate variations in wave energy power from deep waters to the bathymetric breaking point. Finally, the zone with high energy power (where the conversion of this energy into electrical energy would be profitable) of these waves is highlighted on the site, the local water depth at the point of breaking waves is evaluated and results obtained allowed to justify the very energetic character take by these swells on this coast when they are close to the beach

Simulation du potentiel energetique de la houle au port autonome de cotonou

La situation énergétique au Bénin est caractérisée par un faible taux d'accès à l'électricité et une dépendance quasi-totale vis à vis de l'extérieur en énergie électrique. Dans le Golfe de Guinée, on observe une dégradation de la bande côtière due à l'énergie mécanique des vagues qui abordent la côte. Une solution avantageuse pour le Bénin et la Sous-région est la récupération et la transformation de l'énergie des vagues en énergie électrique. Les houles sont des vagues adultes qui se propagent librement à l'interface atmosphère-océan. Dans le Golfe de Guinée, elles ont une allure presque sinusoïdale. Le présent travail les assimile à des houles d'Airy. En admettant que cet écoulement est irrotationnel, nous avons procéder à la mise en équations du problème. L'exploitation de l'équation de Navier Stokes et des différentes équations établies, ont permis d'évaluer les potentiels de vitesses des houles et l'élévation verticale du niveau de la mer. A partir de ces deux paramètres fondamentaux et utilisant les mesures faites par le Millénium Challenge Account (MCA-Bénin) en 2011 dans le cadre du projet d'extension du Port Autonome de Cotonou, nous avons fait une évaluation du potentiel énergétique de la houle sur la côte du Bénin.Mots clés : houle; Golfe de Guinée; potentiel énergétique; relation de dispersion des vagues; bathymétrie; zone côtière

Simulation du potentiel energetique des courants marins internes au port autonome de cotonou en Republique du Benin et son impact sur le fond marin

La région du Golfe de Guinée, a un grand retard sur le plan énergétique alors qu’elle dispose d’énormes potentialités en énergies renouvelables jusqu'ici non exploités parfois méconnues. Dans l'océan en plus des houles on observe souvent des courants marins internes générés par ces dernières. Dans le présent travail, nous considérons la houle et le gradient de salinité de la mer comme les causes majeures des courants marins internes. A partir de l'équation de Navier-Stokes, nous avons déterminé la masse volumique fluctuante et la relation de dispersion de ces courants marins internes. L'étude de la trajectoire d'une particule d’eau mise en mouvement par la houle a permis de déterminer l'évolution de sa vitesse dans le plan vertical. Les résultats obtenus appliqués aux données issues de la campagne de mesures effectuée par le Millenium Challenge Account (MCA- Bénin) dans le cadre du projet d’extension du port autonome de Cotonou, ont permis d'évaluer le potentiel énergétique de ces courants marins internes au port autonome de Cotonou (Bénin). Il ressort de l’analyse de ces résultats que ces courants constituent l’un des facteurs majeur de la dégradation de nos côtes.Mots-clés: Potentiel énergétique; courants marins internes; dégradation du fond marin; hauteur des vagues ; érosion côtière

Waves forcing climate on Benin coast, and the link with climatic index, Gulf of Guinea (West Africa)

Benin's coastline is currently undergoing very marked erosion. This erosion is the consequence of the impact of swells from the South Atlantic and is accentuated by human development. These swells, from weak to moderate energies, drive Benin's coastline evolution. Although crucial, the characteristics of this forcing are not accurately defined. From instantaneous outputs of ERA40 and ERA-Interim's sea state parameters, the annual and seasonal average of significant wave height (Hs), peak period (Tp) and direction (Dir) were determined to characterize wave forcing and extreme event on Benin Coast after a validation using the data of the ALIZEE buoy installed 6 km off the coast of Benin in December, 2015. Hindcast data analysis indicates an important if increasing trend of Hs and Tp. A weak trend of peak direction towards the South West clockwise is observed between 1957 and 2016. The intra-annual variability of Hs shows a marked seasonality, the first one characterized by strong swells from April to October and the second one by moderate swells from October to April. Offshore wave height is positively correlated with AMO (Atlantic Multidecanal Oscillation)

Variations of wave energy power in shoaling zone of Benin coastal zone

Today, we observe at the population level, that the improvement in comfort is accompanied by an increase in the electrical energy required. The predicted exhaustion of fossil energy resources maintains some speculation. Their unequal geographical distribution justifies the energy dependence of Benin overlooked from outside. So it is urgent to explore the various sources of renewable energy available to Benin. In this work, using measurements made ​​by the Millennium Challenge Account (MCA-Benin) as part of the extension of the port of Cotonou, with Boussinesq equations (Peregrine) and Stokes waves dispersion relation, we characterized the variations of various swell parameters (height, wavelength, velocities) in the shoaling zone on the study site and proceeded to estimate variations in wave energy power from deep waters to the bathymetric breaking point. Finally, the zone with high energy power (where the conversion of this energy into electrical energy would be profitable) of these waves is highlighted on the site, the local water depth at the point of breaking waves is evaluated and results obtained allowed to justify the very energetic character take by these swells on this coast when they are close to the beach.</p