29 research outputs found

    Preliminary evaluation of the status of olive-infecting viruses in Morocco

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    Olive is one of the most ancient and important fruit tree crops in Morocco. Olive trees are affected by at least 15 viruses belonging to eight genera. Most of these viruses were isolated from symptomless trees and/or reported in a very limited number of trees. In order to check for the presence of olive-infecting viruses in Morocco, a preliminary survey was conducted during March-April 2014 and a total of 105 samples (cv. Picholine marocaine) were randomly collected from 15 commercial orchards located in three important olive-growing regions: Béni Mellal, Marrakech and Meknès. Samples were tested by RT-PCR, using specific primers, to search for the presence of eight olive viruses: Olive latent virus 1 (OLV-1), Olive latent virus 2 (OLV-2), Strawberry latent ringspot virus (SLRSV), Cucumber mosaic virus (CMV), Arabis mosaic virus (ArMV), Cherry leaf roll virus (CLRV), Olive latent ringspot virus (OLRSV) and Olive leaf yellowing-associated virus (OLYaV). About one third (34.3%) of the trees were infected. In particular, the closterovirus OLYaV was the most widespread, as it was detected in 16.2% of the samples, followed by the necrovirus OLV-1 (8.6%), the oleavirus OLV-2 (3.8%), the cucumovirus CMV (2.8%), the sadwavirus SLRV (1.9%), and the nepovirus ArMV (0.9%). The fact that these infections are mostly latent and the increasing of national demand for propagation material of high sanitary standard call for the implementation of a cleanup using both heat therapy and in vitro propagation for the establishment of olive foundation blocks. Key-words: Olive trees, olive-infecting viruses, Morocc

    The Occurrence of Major Viruses Infecting Zucchini Squash (Cucurbita pepo L.) in Morocco

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    Zucchini squash, Cucurbita pepo L., is one of the most economically important vegetable crops in Morocco. Virus diseases are a major factor in limiting production of zucchini squash in the country. During the growing seasons 2015, 2016 and 2017, the main areas of field-grown cucurbit production in Morocco (Loukkos, Gharb, Bouznika, Doukkala and Souss) were surveyed for the occurrence and distribution of viruses of zucchini squash. A total of 38 commercial fields were visited and inspected for symptoms of virus diseases and 415 leaf samples were collected from plants showing virus-like symptoms for laboratory analyses. ELISA technique was used to detect the following viruses: Zucchini yellow mosaic virus (ZYMV), Squash mosaic virus (SqMV), Cucumber mosaic virus (CMV), Papaya ringspot virus-watermelon strain (PRSV-W) and Cucurbit aphid-borne yellows virus (CABYV). The obtained results showed that virus diseases were widely distributed in the country with an infection rate of 77.6%, especially in the region of Loukkos where 85% of the tested plants were infected by at least one virus. To the best of our knowledge, this isthe first study on the occurrence and geographical distribution of viruses infecting zucchini squash in Morocco. This study provides valuable information, which could be beneficial and of great interest for the researchers, growers and the plant protection services for planning future strategies to control virus diseases of zucchini squash in Morocco

    Real-time monitoring device “panigraph” for bread fermentation with an Arduino-based data acquisition and management system

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    Monitoring and evaluating fermentative performance of sourdough used in bakery products typically involves discontinuous, destructive and costly analyses, resulting in substantial data that is expensive to exploit using conventional methods. The performance of sourdough is determined by its capacity to efficiently leaven the dough in the briefest timeframe possible, while simultaneously reducing the pH to an optimal level. This pH reduction facilitates the activity of enzymes, notably phytases, which break down phytates. Additionally, sourdough has the ability to generate ethanol, a crucial element contributing to the flavor and shelf life of the bread. A new, low-cost, non-destructive device has been developed with a system for real-time data acquisition, monitoring, visualization, as well as data processing, consolidation, and storage, thus simplifying the study of sourdough performance. Multiple specific sensors were integrated into an Arduino Uno board and placed in a connected fermentation chamber controlled by computer-installed software. The developed device enables real-time monitoring of critical parameters during sourdough fermentation. These include dough rising DRC (cm), gas release (CO2, ethanol) (ppmv or ml), pH, conductivity (uS/cm), moisture (%) and dough mass loss (g). Additionally, it measures temperature (°C), air humidity (%) and pressure (mbar) within the fermentation chamber. The device generates graphs, facilitating visual comparisons of sourdough fermentative performance. This graphical representation makes it easy to determine the end of fermentation. The developed application facilitated the management and utilization of the sourdough database. The device enables researchers to save time, reagents and equipment that are usually dedicated to such analyses. It achieves this by offering continuous and simultaneous monitoring of various sourdough fermentation parameters, allowing for an assessment of their fermenting capacity. Keywords: Sourdough, bread, fermentative capacity, data acquisition, monitorin

    Synbiotics and their Antioxidant Properties, Mechanisms, and Benefits on Human and Animal Health: A Narrative Review

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    peer reviewedAntioxidants are often associated with a variety of anti-aging compounds that can ensure human and animal health longevity. Foods and diet supplements from animals and plants are the common exogenous sources of antioxidants. However, microbial-based products, including probiotics and their derivatives, have been recognized for their antioxidant properties through numerous studies and clinical trials. While the number of publications on probiotic antioxidant capacities and action mechanisms is expanding, that of synbiotics combining probiotics with prebiotics is still emerging. Here, the antioxidant metabolites and properties of synbiotics, their modes of action, and their different effects on human and animal health are reviewed and discussed. Synbiotics can generate almost unlimited possibilities of antioxidant compounds, which may have superior performance compared to those of their components through additive or complementary effects, and especially by synergistic actions. Either combined with antioxidant prebiotics or not, probiotics can convert these substrates to generate antioxidant compounds with superior activities. Such synbiotic-based new routes for supplying natural antioxidants appear relevant and promising in human and animal health prevention and treatment. A better understanding of various component interactions within synbiotics is key to generating a higher quality, quantity, and bioavailability of antioxidants from these biotic sources.1. No poverty2. Zero hunger3. Good health and well-being9. Industry, innovation and infrastructure17. Partnerships for the goal

    Value addition of some Moroccan regional products by liquid fermentation: production of date and apple vinegars

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    Six strains of acetic acid bacteria were isolated from Moroccan local products and evaluated for their industrial vinegar production potential. Two of them, namely AF01 and CV01, isolated from apple (Malus domestica) and cactus (Opuntia ficus-indica) fruits, respectively, were selected and investigated for their thermoresistant and thermophilic properties. A biochemical and molecular study based on a 16SrDNA gene sequence analysis confirmed that the two isolated strains belong to Acetobacter pasteurianus with 99 % of homology. Their growth and acetic acid production capacity were compared with (1) the thermoresistant reference strain A. senegalensis isolated from mango (Senegal) and (2) other, wild acetic strains belonging to A. pasteurianus (LMG 1632, LMG 1607, LMG 1701, DSM 2324 and DSM 4491). The two strains showed very good growth and noticeable acetic acid production ability at high temperatures (38 to 41°C). A thermophilic character was noted for AF01 strain. Indeed, this bacterium grew better at 38 than at 30°C. Subsequently, a semi-continuous fermentation was performed in a 20L Bioreactor for both selected strains. A total amount of 7.64% and 10.08% acetic acid was achieved at the end of fermentation, respectively for AF01 and CV01 strains. Process fermentation of CV01 strain was marked by the ability to produce gluconic acid during acetic fermentation. Finally, an enzymatic study was carried out on the selected strains AF01 and CV01 to confirm the tolerance of their enzymes responsible for acetic fermentation process to high temperature. Results clearly showed that the two strains exhibited high ADH and ALDH enzyme activity at either 30 or 38 °C as compared to the mesophilic reference strain LMG 1632 which exhibited marked thermal inactivation rate. It is concluded that the two selected strains are well-suited to industrial use for vinegar production in Morocco

    Maîtrise de la fermentation alcoolique sous stress éthanolique, thermique et osmotique de la souche Saccharomyces cerevisiae YS-DN1 en vue de la préparation du vinaigre de fruits

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    The purpose of the present study is to isolate, identify and characterize new yeast species of industrial interest. A total of 54 strains were isolated and identified from agricultural raw products and from by-products of the food industry. Among these, four strains were selected, purified and tested for their ability to perform efficient fermentation on Bouslikhène date juice. After the sequencing of the 18S gene of the ribosomal DNA, the two strains YS-DN1 and YS-M isolated respectively from dates and molasses have been identified belonging to Saccharomyces cerevisiae species. In addition, the other two strains, YS-OMP and YS-G isolated from olives and grapes belonged to Kluyveromyces marxianus (78% homology) and Candida utilis (89% homology) species, respectively. In addition, YS-DN1 strain showed the highest performance in terms of ethanol production in comparison with two other industrial reference strains. YS-DN1 strain was the only one that was able to grow at a temperature ranged from 35 to 40°C in the presence of a high alcoholic concentration and aggressive osmotic pressure condition. Finally, production of the cellular biomass of YS-DN1 strain was improved by optimization of temperature, Brix and pH fixed respectively at 29.75°C, 15.7% and 4.15. These values allowed to obtain a maximum of cells of about 8.4x10 8 UFC/ml. It was concluded that this strain is well suited for fruit vinegar production at a large-scale. Keywords: Isolation, Yeasts, Fermentation, Vinegar, Optimization, Dates, StressorsLa présente étude a pour but d’isoler, d’identifier et de caractériser de nouvelles souches de levures d’intérêt industriel. Un total de 54 levures ont été isolées et identifiées à partir de produits agricoles brutes et de sous-produits de l’industrie agro-alimentaire. Parmi ces isolats, quatre souches ont été retenues, purifiées et testées pour leur performance de fermentation sur un jus de dattes de variété Bouslikhène. D’après le séquençage du gène 18S de l’ADN ribosomal, les deux souches YS-DN1 et YS-M isolées respectivement à partir des dattes et de la mélasse ont été identifiées appartenant à l’espèce Saccharomyces cerevisiae. Par ailleurs, les deux autres souches YS-OPM et YS-G isolées des olives et des raisins appartiennent respectivement aux espèces Kluyveromyces marxianus, avec 78 % d’homologie et Candida utilis à 89% d’homologie. D’autre part, la souche YS-DN1, s’est identifiée comme la plus performante dans la production d’éthanol en comparaison à deux autres souches industrielles de référence. La levure YS-DN1 était l’unique souche capable de croître à une température entre 35 et 40°C en présence d’un taux alcoolique élevé et une pression osmotique agressive. Finalement, la production de la biomasse cellulaire de la souche YS -DN1 a été améliorée par optimisation des facteurs température, Brix et pH fixés respectivement à 29.75°C, 15.7% et 4.15. Ces valeurs ont permis d’obtenir un maximum de cellules de l’ordre de 8.4x10 8 UFC/ml. Il a été conclu que cette souche pourrait bien s’adapter à des usages industriels pour la production du vinaigre de fruits à grande échelle. Mots clés: Isolement, levures, Fermentation, Vinaigre, Optimisation, Dattes, Stres

    Nature-based One Health approaches to urban agriculture can deliver food and nutrition security

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    peer reviewedThe increasing global human population is projected to reach 9.7 billion people by 2050. This population growth is currently linked to the trends of world-wide urbanization, growth of megacities and shifting dietary patterns. While humankind faces the daunting challenge of feeding and providing healthy lives for its teeming populations, urban agriculture holds promise for improving the quality of life in cities. Fortunately, policymakers and planners are accepting the need to support urban fringe farmers to increase the resilience of food systems while efficiently managing already strained natural resources. We argue that for urban agriculture to significantly increase food yields, it is crucial to adopt a One Health approach to agriculture and environmental stewardship. Here, we propose six nature-based and climate-smart approaches to accelerate the transition towards more sustainable food systems. These approaches include reducing the reliance on synthetic agricultural inputs, increasing biodiversity through producing locally adapted crops and livestock breeds, using probiotics and postbiotics, and adopting portable digital decision support systems. Such radical approaches to transforming food production will require cross-sectoral stakeholder engagement at international, national, and community levels to protect biodiversity and the environment whilst ensuring sustainable and nutritious diets that are culturally acceptable, accessible, and affordable for all.1. No poverty2. Zero hunger3. Good health and well-being10. Reduced inequalities11. Sustainable cities and communities12. Responsible consumption and production13. Climate action17. Partnerships for the goal

    Application of postharvest biotechnologies for the valorization of Moroccan local products using selected microorganisms involved in the fermentation of fruits: Case of vinegar fermentation

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    Dans cette étude, de nouvelles souches microbiennes (levures et bactéries acétiques) ont été isolées, sélectionnées, identifiées et caractérisées pour évaluer leur usage comme starters pour la production industrielle de vinaigre de fruits. Dans un premier temps, la levure Saccharomyces cerevisiae YS-DN1 a été isolée à partir de dattes locales et étudiée pour ces pouvoirs de fermentation des sucres et de résistance aux différents facteurs de stress (éthanolique, thermique et osmotique). Cette souche s’est distinguée comme étant la plus performante dans la production d’éthanol en comparaison à deux autres souches industrielles de référence. En effet, YS-DN1 était la seule souche capable de se développer à une température entre 35 et 40°C en présence d’un taux alcoolique élevé (>8% éthanol) et une pression osmotique agressive (>18 °Brix). Dans un deuxième temps, deux souches de bactéries acétiques CV01 et AF01, identifiées par des techniques moléculaires comme étant affiliées à l’espèce Acetobacter pasteurianus, ont été isolées respectivement de cactus et de pommes. A l’issue des caractérisations physiologiques et des cinétiques de fermentation réalisées en erlens et en bioréacteurs (6 L, 20 L et 500 L), ces deux souches ont montré des pouvoirs de thermotolérance et d’acétification notables. L’étude enzymatique réalisée sur les enzymes membranaires ADH et ALDH formant le complexe enzymatique impliqué dans le processus d’oxydation de l’éthanol a révélé que, contrairement aux souches de référence, ces enzymes maintiennent une activité normale à haute température (38°C). L’étude cinétique en bioréacteur 20 L a montré que la souche CV01 était moins sensible à la variation de la composition du milieu de fermentation et a pu produire plus d’acide acétique (10 g/L) que la souche AF01. Durant le même cycle de fermentation, la souche CV01 était notablement la seule souche capable d’orienter son mécanisme métabolique pour la production de l’acide gluconique simultanément avec l’acide acétique. Par ailleurs, la méthode des surfaces de réponse (RSM) a été utilisée pour l’optimisation de la production en biomasse de la souche CV01. Les valeurs optimales des facteurs influents, à savoir l’éthanol, l’acide acétique, le glucose et le pH, permettant d’obtenir le maximum de biomasse cellulaire (2.21 g/L) étaient de 28.18 g/L, 10.12 g/L, 15.15 g/L et 5.33, respectivement. Dans une troisième partie, la souche A. pasteurianus CV01 a été évaluée pour sa capacité à résister aux conditions de stress thermique en bioréacteur. Les résultats obtenus montrent une habilité de cette souche à contrecarrer l’augmentation excessive de température (>35°C) au cours d’un cycle de fermentation sans refroidissement. En outre, un protocole de démarrage de fermentation en mode semi-continu a été proposé et adopté pour la production de vinaigre de fruits en bioréacteur 500 L. La caractérisation aromatique du vinaigre de pomme produit à l’échelle pilote moyennant la technique de l’espace de tête – microextraction en phase solide (HS-SPME) – a permis d’identifier dans la composition de son arôme des molécules associées à des descripteurs généralement appréciés . Ces souches, caractérisées pour leur thermotolérance notable, pourront être utilisées comme starters pour la production à grande échelle de vinaigre de fruits

    Simultaneous production of acetic and gluconic acids by a thermotolerant Acetobacter strain during acetous fermentation in a bioreactor

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    The activity of bacterial strains significantly influences the quality and the taste of vinegar. Previous studies of acetic acid bacteria have primarily focused on the ability of bacterial strains to produce high amounts of acetic acid. However, few studies have examined the production of gluconic acid during acetous fermentation at high temperatures. The production of vinegar at high temperatures by two strains of acetic acid bacteria isolated from apple and cactus fruits, namely AF01 and CV01, respectively, was evaluated in this study. The simultaneous production of gluconic and acetic acids was also examined in this study. Biochemical and molecular identification based on a 16s rDNA sequence analysis confirmed that these strains can be classified as Acetobacter pasteurianus. To assess the ability of the isolated strains to grow and produce acetic acid and gluconic acid at high temperatures, a semi-continuous fermentation was performed in a 20-L bioreactor. The two strains abundantly grew at a high temperature (41°C). At the end of the fermentation, the AF01 and CV01 strains yielded acetic acid concentrations of 7.64% (w/v) and 10.08% (w/v), respectively. Interestingly, CV01 was able to simultaneously produce acetic and gluconic acids during acetic fermentation, whereas AF01 mainly produced acetic acid. In addition, CV01 was less sensitive to ethanol depletion during semi-continuous fermentation. Finally, the enzymatic study showed that the two strains exhibited high ADH and ALDH enzyme activity at 38°C compared with the mesophilic reference strain LMG 1632, which was significantly susceptible to thermal inactivation
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