Isolement des bactéries lactiques à partir des produits laitiers traditionnels Marocains et formulation d’un lait fermenté proche du Kéfir

Les bactéries lactiques par leur biodiversité sont largement utilisées dans l’industrie agroalimentaire. L’objectif de cette étude est donc l’isolement des bactéries lactiques à partir de lben et jben marocains, l’étude de la vitesse d’acidification des isolats en culture pure et en culture mixte afin de trouver la meilleure combinaison à caractère acidifiant très rapide et très élevé et son utilisation pour formuler une boisson lactée fermentée proche du Kéfir. Les résultats montrent que les isolats obtenus appartiennent aux genres Lactobacillus, Lactococcus et Leuconostoc, que les Lactobacillus et les Lactococcus isolés en culture pure provoquent tous une diminution du pH du lait de 6,5 à 4,2 au bout de 24 heures de fermentation et que la souche Lb4 du genre Lactobacillus possède une forte propriété acidifiante. Cette souche a été utilisée en combinaison avec les Leuconostoc et les Lactococcus (CM1, CM2, CM3) et a donné une vitesse d’acidification plus rapide et un pH plus bas. Une boisson lactée fermentée proche du Kéfir qui est une boisson très reconnue par ses effets sanitaires et thérapeutiques est alors produite grâce à cette dernière combinaison et à l’ajout des levures (saccharomycess cerevisiae) et des bactéries acétiques (Acetobacter). Le résultat de ce travail a noté une bonne appréciation du nouveau produit par le jury de dégustation et une forte ressemblance au Kéfir qui est un produit d’origine Russe.Mots-clés: bactéries lactiques, Lactobacillus, Leuconostoc, Lactococcus, Lben, Jben, Kéfir. Isolation of lactic acid bacteria from traditional Moroccan dairy products and formulation of a loved fermented milk KefirLactic acid bacteria for their biodiversity and their therapeutic properties are widely used in the food industry. the interest of this study is the isolation of lactic acid bacteria from Lben and Jben Moroccan studying the acidification rate of isolates in pure culture and in mixed culture in order to find the best combination for fast acidifying character and very expensive and its use to make a fermented milk close Kefir . The results show that the isolates belong to the genera Lactobacillus, Lactococcus and Leuconostoc, Lactobacillus and the isolated pure culture Lactococcus all cause a decrease in pH of the milk to 6.5 to 4.2 after 24 hours fermentation and the LB4 strain of Lactobacillus has a strong acidifying property. This strain was used in combination with Lactococcus and Leuconostoc (CM1, CM2, CM3) gave a faster speed of acidification and a low pH. A fermented milk drink close Kefir is a highly recognized by its health and therapeutic effects beverage is then produced by the latter combination and the addition of yeast (saccharomycess cerevisiae) and acetic acid bacteria (Acetobacter). The result of this work has been a good appreciation of the new product by the tasting panel and a strong resemblance to Kefir is a Russian original product.Keywords: lactic acid bacteria, Lactobacillus, Leuconostoc, Lactococcus, Lben, Jben, Kefir

On the Suitability of Almond Shells for the Manufacture of a Natural Low-Cost Bioadsorbent to Remove Brilliant Green: Kinetics and Equilibrium Isotherms Study

Almond production generates a large number of coproducts, but the farmer’s interest mainly focuses on the nutritional and commercial aspects of the kernel for getting the best return from their harvests. Thus, almond coproducts such as almond shells that represent more than 70% of biomass remain underexplored. In this work, the suitability of almond shell powder (ASP) as a natural low-cost adsorbent was evaluated in the adsorption of brilliant green dye (BG), which is known as a chemical pollutant. Brunauer–Emmett–Teller (BET) method, for the determination of specific surface area, Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) techniques were performed to characterize the ASP adsorbent. The batch adsorption kinetic study for the removal of BG dye was carried out by varying pH, temperature, initial concentration of the dye, bioadsorbent dose, and contact time. It was found that 98% of BG dye is removed under the following optimal experimental conditions: ASP bioadsorbent dose of 1 g/L at T = 25°C, pH = 6.8, and C0 = 1 g/L, which proves that ASP can be used as an excellent low-cost bioadsorbent for the removal of BG dye from wastewater. The experimental isotherm data were analyzed using Freundlich and Langmuir models. The results show the best correlation with single-layer adsorption, and the adsorption kinetics seems to follow a pseudo-second-order model

Valorization of Date Pits as an Effective Biosorbent for Remazol Brilliant Blue Adsorption from Aqueous Solution

In this work, the adsorption of Remazol Brilliant Blue (RBB) over raw date pits (RDPs) as an inexpensive adsorbent has been examined. In addition, all parameters such as the adsorbent mass, solution pH, RDP particle size, RBB initial concentration, and temperature on the adsorption of RBB influencing the adsorption procedure were studied to provide fundamental information of the adsorption equilibrium. The characterization of RDP material is investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). Based on the calculation, the kinetic rate of the adsorption was well modeled by pseudo-second-order and Langmuir isotherm. Surface functional groups of RDP have substantially been influenced by the adsorption characteristics of RBB. The capacity of the adsorption has achieved 105 mg/g and a removal efficiency of 90.4% at 1.5 g/L RDP mass, 40 mg/L initial dye concentration, pH 2, temperature of 328 K, 40 µm particle size, and contact time of 50 min. The capacity of the adsorption could reach 198 mg/g by increasing the ionic strength of RBB solution. Desorption tests showed that RDP adsorbent has the disadvantage of losing efficiency while reusing for many cycles. However, it still abundant and inexpensive. Therefore, RDP can be used as a potential low-cost bioabsorbent for the elimination of RBB from wastewater