Differentiation of entomopathogenic fungus Beauveria bassiana (Ascomycetes: Hypocreales) isolates by PCR-RFLP

The entomopathogenic fungus Beauveria bassiana is a promising biological control agent of several insect pests in agriculture. Molecular approaches (PCR, DNA sequence analysis and PCR-RFLP) were used in our research as tools for the identification of different B. bassiana isolates. Our work consisted in identifying the 18S, ITS1, 5.8S, ITS2 and 28S regions of B. bassiana ribosomal DNA. The DNA sequences of the amplified regions showed that the 18S rDNA is the most conserved unit, with a high homology (99.5%) between the isolates studied, while the 3’ end of the 28S rDNA has a great variability, which makes it possible to differentiate the isolates. The PCR-RFLP method was used to monitor isolates of B. bassiana and distinguish them in a target pest, Lygus lineolaris. This method involved two main steps. First, PCR was used to amplify a region of the 28S gene of B. bassiana. Second, this PCR product was digested using restriction endonucleases, and the fragments produced were compared using gel electrophoresis. Because of the high specificity and sensitivity of PCR-RFLP, it was possible to discriminate between B. bassiana isolates using spores scraped from the surface of an infected insect as samples.Le champignon entomopathogène Beauveria bassiana suscite de plus en plus d’intérêt en recherche et constitue une avenue intéressante en lutte biologique contre plusieurs insectes ravageurs en agriculture. Différentes approches (PCR, analyse des séquences d’ADN et PCR-RFLP) ont été utilisées lors de cette étude comme outils moléculaires d’identification de différents isolats de B. bassiana. Notre travail a consisté à identifier les régions 18S, ITS1, 5.8S, ITS2 et 28S de l’ADN ribosomal de B. bassiana. Les séquences d’ADN des régions amplifiées ont démontré que la région 18S de l’ADNr était la sous-unité la plus conservée, avec une homologie de 99,5 % entre les isolats étudiés, tandis que l’extrémité 3’ du gène 28S a accumulé beaucoup de variabilité et peut donc être utilisée pour différencier les isolats de B. bassiana. La technique PCR-RFLP a été utilisée pour réaliser le suivi d’isolats de B. bassiana chez un ravageur ciblé, Lygus lineolaris, et pour les distinguer. Cette méthode comprenait deux étapes. Premièrement, la PCR était utilisée pour amplifier une région du gène 28S de B. bassiana. Deuxièmement, ce produit de PCR était digéré à l’aide des endonucléases de restriction et les fragments produits ont été comparés en utilisant l’électrophorèse sur gel. En raison de la grande spécificité et sensibilité de la PCR-RFLP, il a été possible de différencier les isolats de B. bassiana en utilisant comme échantillons des spores prélevées à la surface d’un insecte infecté

Improving the Quality and Safety of Barley by Controlled Homolactic Fermentation with Lactic Acid Bacteria

Fermentation by lactic acid bacteria can improve the nutritional and hygienic quality of barley, as well as its organoleptic properties. The aim of this study was to select a suitable lactic ferment to add value to barley through a controlled homolactic fermentation process, which can be used to produce a natural base product for broiler feed. Four different combinations of lactic strains were tested for their acidifying power, antibacterial activity, and fermentation performanceThe mixed culture of homolactic ferment FS4, composed of Lactobacillus plantarum (SC1), Pediococcus spp (SC4), and Lactococcus lactis ssp (SC5), showed the best result in terms of pH reduction, acidity production, and inhibition of spoilage bacteria. The in vivo application of the ferment FS4 on barley resulted in a decrease in pH to 4.12 after 15 days of fermentation, and an improvement in its hygienic quality, with the possibility of also enhancing its nutritional quality. This study demonstrated that FS4 is a suitable lactic ferment for valorizing barley through a controlled homolactic fermentation process, which can be used to produce a natural base product for animal feed with improved quality and safety

Factors Affecting the Quality of Canola Grains and Their Implications for Grain-Based Foods

International audienceCanola, Brassica napus L., is a major oilseed crop that has various uses in the food, feed, and industrial sectors. It is one of the most widely produced and consumed oilseeds in the world because of its high oil content and favorable fatty acid composition. Canola grains and their derived products, such as canola oil, meal, flour, and bakery products, have a high potential for food applications as they offer various nutritional and functional benefits. However, they are affected by various factors during the production cycle, post-harvest processing, and storage. These factors may compromise their quality and quantity by affecting their chemical composition, physical properties, functional characteristics, and sensory attributes. Therefore, it is important to optimize the production and processing methods of canola grains and their derived products to ensure their safety, stability, and suitability for different food applications. This literature review provides a comprehensive overview of how these factors affect the quality of canola grains and their derived products. The review also suggests future research needs and challenges for enhancing canola quality and its utilization in food

Environmental-Friendly Adsorbent Composite Based on Hydroxyapatite/Hydroxypropyl Methyl-Cellulose for Removal of Cationic Dyes from an Aqueous Solution

International audienceThe aim of this study is to develop a new, efficient, and inexpensive natural-based adsorbent with high efficacy for the cationic dye methylene blue (MB). A natural-based nanocomposite based on hydroxyapatite (HAp) and hydroxypropyl methylcellulose (HPMC) was selected for this purpose. It was synthesized by the dissolution/reprecipitation method. A film with a homogeneous and smooth surface composed of nanoparticles was prepared from the nanocomposite. HPMC and HAp biopolymers were selected due to their compatibility, biodegradability, and non-toxicity. Total reflectance infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and calorimetric/thermal gravimetric (DSC/TGA) analysis results revealed the existence of strong physical interaction between the composite components. Scanning electron microscopy (SEM) observations show a composite sheet with a homogenous and smooth surface, indicating excellent compatibility between HPMC and HAp in the composite. The nanocomposite was evaluated as an adsorbent for organic dyes in an aqueous solution. The effects of solution pH, initial MB concentration, composite concentration, and adsorption time on the adsorption efficiency were evaluated. The highest adsorption rate was seen as 52.0 mg of MB/g composite. The adsorption rate reached equilibrium in about 20 min. Fitting of the adsorption data to the Langmuir and Freundlich adsorption models was investigated. Results showed that the adsorption process follows the Langmuir isotherm model. The kinetic study results revealed that the adsorption process was pseudo-second-order. The herein composite is an excellent alternative for use as contemporary industrial-scale adsorbents