Papers by Mohamed RAHOUTI
Effet du stress salin sur Verticillium albo-atrum: pathogénicité et production d'enzymes cellulolytiques in vitro
Cryptogamie Mycologie, 2003
La tomate var Marmande est hautement sensible a l'infection par l'isolat P80 de Verticill... more La tomate var Marmande est hautement sensible a l'infection par l'isolat P80 de Verticillium albo-atrum et peu sensible a l'isolat P 3 A du meme champignon. Les arrosages repetes avec une solution nutritive enrichie en NaCl (80mM) des plantes infectees entrainent une aggravation des symptomes causes par l'isolat pathogene et l'acquisition de nouvelles aptitudes pathogenes pour l'isolat peu agressif. En culture pure sur milieu CMC, l'effet de la salinite se manifeste chez les deux isolats par une legere reduction de la croissance mycelienne et une nette augmentation de l'activite carboxymethylcellulase in vitro. La correlation entre les performances de l'enzyme sous stress salin et la pathogenecite de Verticillium est discutee.
Food Control, 2013
Eighty one (81) samples of durum wheat collected from seven areas from Morocco (Khmiset, Beni Mel... more Eighty one (81) samples of durum wheat collected from seven areas from Morocco (Khmiset, Beni Mellal, Settat, FèseMeknès, SkhirateTémara, Tansift-El Haouz and RabateSalé) were surveyed for the presence of the mycotoxin deoxynivalenol (DON). Samples were extracted with water, the extracts were purified by immunoaffinity chromatography (IAC) columns and DON was then identified and quantified with liquid chromatography (LC) coupled to diode array detection (DAD). Analytical results showed that 9 out of 81 total samples (11.1%) were contaminated with DON. DON levels in positive samples ranged between 65 and 1310 mg/kg. The maximum contamination level of DON (1310 mg/kg) was found in a durum wheat sample from RabateSalé area, while the minimum value (65 mg/kg) was registered in a sample from Beni Mellal area. The mean DON level in positive samples was 502.1 AE 40.4 mg/kg. Only one previous work exists on DON contamination in Moroccan wheat samples.
Metabolism of ferulic and syringic acids by micromycetes
Microbiologica, 1990
The ability of 814 strains of Micromycetes to grow on ferulic and syringic acids was investigated... more The ability of 814 strains of Micromycetes to grow on ferulic and syringic acids was investigated. After cultivation on solid media, 106 and 108 strains were selected and cultivated in liquid synthetic medium. Chromatographic analysis allowed classification of fungi into different groups according to the consumption of phenolic compounds and the appearance of new metabolites. Finally, Paecilomyces variotii and Pestalotia palmarum were chosen and cultivated in the presence of ferulic acid in two different culture media. These two Fungi Imperfecti were able to consume the phenolic compound rapidly and completely.
Experimental Study of Physical Properties and Impact Bending Strength of Clonal Eucalyptus Wood
International Journal of Thermophysics
Etude de la toxicité des composés phénoliques modèles de la lignine vis-à-vis de 1040 souches de champignons
Revue Marocaine des Sciences Agronomiques et Vétérinaires, 2011
La toxicite de 7 composes phenoliques modeles de la lignine vis-a-vis de 1040 champignons est etu... more La toxicite de 7 composes phenoliques modeles de la lignine vis-a-vis de 1040 champignons est etudiee. La plupart des souches ont une bonne tolerance a ces composes.. Les acides protocatechique, syringique et vanillique sont les moins toxiques, alors que le phenol et le catechol sont les plus toxiques . L'acide ferulique et le gaiacol sont moyennement toxiques. Certains groupes taxonomiq1,les comme les Zygomycetes sont tres resistants a la toxicite de ces phenols; tandis que d'autres tels que les Agonomycetes le sont moins. Les champignons deporvus d'activite phenoloxydasique tolerent mieux la presence du catechol et du phenol. Quant aux autres phenols, leur toxicite ne semble pas etre modifiee par la presence ou non de ces enzymes. L'addition d'un carboxyle sur le noyau aromatique du catechol et du gaiacol diminue nettement la toxicite de ces 2 composes; alors que l'addition d'un hydroxyle au phenol ou d'un groupement ethylenique a l'acide vailil...
Comparison between the recovery rate of three concentration protocols of water samples intended for analysis by Molecular Biology: membrane filtration, filtration on gauze pad and centrifugation
Saudi Journal of Biological Sciences, 2021
The presence of microorganisms (bacteria, protozoa, viruses, etc.) in water is a crucial indicato... more The presence of microorganisms (bacteria, protozoa, viruses, etc.) in water is a crucial indicator of its quality and safety. The detection of these microorganisms by conventional and classical techniques is widely used in water quality control laboratories; nevertheless these methods have limitations in terms of rapidity and precision of results. The use of Molecular Biology has been a great evolution in the techniques of water analysis. However, the choice of the concentration protocol allowing for the best rate of microorganism recovery in a suspension remains a real challenge. The objective of this experimental study is to compare the recovery rate of three different protocols of water concentration (membrane filtration, filtration on gauze pad and centrifugation) for samples intended for analysis by polymerase chain reaction PCR. Which can then serve as a reference protocol for water quality control laboratories. The experimental results have shown that the membrane filtration protocol yields the best recovery rate and concentration of microorganisms followed by filtration on gauze pad, while the centrifugation protocol (8000g, 10 min, 22 °C) gives the lowest rate of recovery out of the three protocols. The experimental results obtained through this study allows us to contribute to the optimization and standardization of water samples concentration techniques intended for analysis by Molecular Biology.
Chemosphere, 1999
Growth of 1044 strains and species of micromycetes on 7 phenolic lignin model compounds as sole c... more Growth of 1044 strains and species of micromycetes on 7 phenolic lignin model compounds as sole carbon source has been investigated. It was found that phenol inhibited growth, followed by catechol and guaiacol. Protocatechuic, vanillic, syringic and ferulic acids allowed the highest growth. Most of the fungi grown on protocatechuic, vanillic, ferulic and syringic acids produced normal fructifications whereas fructification was perturbed on guaiacol and phenol. Guaiacol, syringic acid and catechol were the strongest pigment inducers. Generally fungi imperfecti had a good growth on phenolics, however only a limited number of Yeasts could use these compounds. It appears that the biodegradability of the phenolic compounds declined with the decrease of their water solubility.
Acta Botanica Gallica, 2006
Activite antifongique des huiles essentielles de Ocimum basilicum L. (Lamiaceae) et Cymbopogon sc... more Activite antifongique des huiles essentielles de Ocimum basilicum L. (Lamiaceae) et Cymbopogon schoenanthus (L.) Spreng. (Poaceae) sur des micromycetes influen~ant Ia germination du Ma'is et du Niebe par Koffi Apeti Gbogboci), Komlan Batawilae), Kouassi Ananici), Mireille Prince-David(1), Messanvi Gbeassore), Philippe Bouchet(4) et Koffi Akpaganae)
Journal of the Korean Wood Science and Technology, 2019
Radial and tangential water diffusion in Eucalyptus globulus wood was investigated using three ma... more Radial and tangential water diffusion in Eucalyptus globulus wood was investigated using three mature trees from a forest in Khemis Sahel (North Morocco). Absorption and desorption kinetics experiments were conducted at ambient temperature (25 °C) and 30 °C, respectively, and a relative humidity of 60%. The diffusion coefficients in the two directions were determined under imposed hygrothermal conditions; they were greater in the radial direction for the absorption as well as desorption processes. Convective drying under load, preceded by reconditioning and followed up by balancing, revealed the drying conditions that corresponded to the appropriate drying schedules for E. globulus wood. This was verified by measuring the cracks and bowsbefore and after drying of boards.
Informatics in Medicine Unlocked, 2021
COVID-19 is an infectious disease caused by the newly discovered SARS-CoV-2 virus. This virus cau... more COVID-19 is an infectious disease caused by the newly discovered SARS-CoV-2 virus. This virus causes a respiratory tract infection, symptoms include dry cough, fever, tiredness and in more severe cases, breathing difficulty. SARS-CoV-2 is an extremely contagious virus that is spreading rapidly all over the world and the scientific community is working tirelessly to find an effective treatment. This paper aims to determine the origin of this virus by comparing its nucleic acid sequence with all members of the coronaviridae family. This study uses a new approach based on the combination of three powerful techniques which are: Ngrams (For text categorization), Principal Component Analysis (For dimensionality reduction) and Random Forest algorithm (For supervised classification). The experimental results have shown that a large set of SARS-CoV-2 genomes, collected from different locations around the world, present significant similarities to those found in pangolins. This finding confirms some previous results obtained by other methods, which also suggest that pangolins should be considered as possible hosts in the emergence of the new coronavirus.
Bulletin de la Société Royale des Sciences de Liège, 2016
L’efficacité in vitro de silicate, d’hydroxyde, l’oxyde, du sulfate et d’hypochlorite de calcium... more L’efficacité in vitro de silicate, d’hydroxyde, l’oxyde, du sulfate et d’hypochlorite de calcium a été testée sur le développement des champignons responsables de la pourriture des fruits d’agrumes en post-récolte. Les composés calciques inorganiques ont été testés in vitro à 200, 400, 600, 800 et 1000 ppm contre Alternaria alternata, Aspergillus niger, Fusarium oxysporum, Penicillium digitatum, Rhizopus stolonifer, Penicillium italicum isolées à partir de deux variétés d’agrumes Clémentines et Oranges. Le silicate, l’hydroxyde et l’oxyde de calcium se sont avérés efficaces sur les isolats de F. oxysporum, d’A. alternata, d’A. niger, de P. digitatum, de R. stolonifer et de P. italicum à 1000 ppm avec des pourcentages d’inhibition compris entre 66,7% et 85,7% pour la croissance mycélienne, 62,8 et 92,4% pour la production des conidies et 82,8 et 98,8 % pour leur germination. Les champignons testés sont moyennement sensibles au sulfate de calcium alors que l’hypochlorite de calcium e...
Improvement of Harvesting Practices for Sustainable Development of Moroccan Rosemary Mediterranean’s Scrublands
Journal of Essential Oil Bearing Plants, 2017
Abstract In Morocco, rosemary stands are mainly threatened by current practices which compromise ... more Abstract In Morocco, rosemary stands are mainly threatened by current practices which compromise their sustainability. To improve harvesting practices within natural stands, an experimental design was followed during 4 years in Debdou forest, Eastern Region of Morocco, where rosemary covers large areas. Harvesting practices tested to operate rosemary at different seasons of the year influenced regeneration of leaf biomass and essential oils production. During spring, the clear-cut allowed the best resumption, the highest yield of essential oil (2.03 %), and a supported production in leaf biomass. In summer, harvesting operations must be avoided because of their negative effect on vegetal growth and essential oils yields. Harvesting half of the clumps during autumn has the advantage to keep the part of the plant that is going to flower soon at the end of autumn, thus allowing rosemary clumps to play, firstly, their nectar-producing to beekeeping role, and secondly, to ensure the production of seeds for natural regeneration. Finally, winter is a convenient period for the rejuvenation of rosemary shrubs. Therefore, the best rate of resumption was obtained by clear-cutting (179.4 %) which allows a better regeneration and an improvement of the production. The best essential oil yields extracted from leaves, by hydro-distillation, were obtained during spring. Results of a chemical analysis, by GC-MS, showed that chemical composition did not varied drastically during different seasons and these essential oils were characterized by high amounts of 1,8-cineol (51.6–54.9 %) followed by significant quantities of α-pinene (6.4–8.5 %), camphor (12.6–16.9 %) and borneol (5.3–8.6 %).
Madera y Bosques, 2020
Testing environmentaly-friendly plant essential oils for their ability to protect non-durable woo... more Testing environmentaly-friendly plant essential oils for their ability to protect non-durable wood against wood decay fungi is a research topic of current interest. In this study, wood preservative potential of extracts from the wood of the durable species, Tetraclinis articulata and Cedrus atlantica were assessed on non-durable maritime pine sapwood, Pinus pinaster var atlantica, after exposure to three wood decay fungi, according to the EN 113 Standard. Significant differences were observed between treatment effects of these extracts, between fungal decay levels and between oils concentrations. Overall, mean mass losses of treated wood specimens were above 8%. T. articulata root burl extract gave the best protection level for this type of wood against Gleophyllum trabeum and Rhodonia placenta but only at test concentrations above 0.1%v/v. However, efficacy levels of both extracts’ treatments, applied at the tested concentrations, were judged insufficient on the basis of the NF EN ...
In Morocco, as elsewhere in the world, the phenomenon of eutrophication threatens to destroy the ... more In Morocco, as elsewhere in the world, the phenomenon of eutrophication threatens to destroy the fragile balance of most water resources, especially water reservoirs and dams. To contribute to the knowledge of the key factors involved in the sound understanding and proper management of this phenomenon, we undertook the task of exploiting a basic physicochemical Smir dam data, collected from 2001 through 2008, with a view to developing mathematical approaches and numerical models susceptible of providing information on the current status as well as expected future developments relative to the changes that are likely to trigger this process. To this end, we have analyzed the behaviour of several parameters; namely, phosphorus, a major element that characterizes the eutrophication of inland waters. The results obtained indicate the possibility of predicting the behaviour of the total phosphorus in function of several environmental variables and the corresponding trophic state.
مجلة الواحات للبحوث والدراسات, 2016
Mechanical Properties of Clonal Eucalyptus Wood
International Journal of Thermophysics, 2021
The mechanical properties of wood are important factors to demonstrate its suitability in constru... more The mechanical properties of wood are important factors to demonstrate its suitability in construction and crafts applications. The aim of this study is to evaluate the mechanical parameters for two clones of eucalyptus wood ( E. grandis ; E. camaldulensis ). At 12 % moisture content, axial compression, axial tension, four-points bending and elasticity dynamic modulus resulting from the propagation of ultrasound in the wood longitudinal direction are investigated. The obtained results show that E. camaldulensis wood exhibits high rupture stress, a higher static modulus of elasticity in both bending and axial tension along with a higher dynamic modulus of elasticity. Additionally, E. camaldulensis has a lower elasticity modulus value in axial compression. There are statistically significant differences ( P < 0.05) between the mean measured parameters of these two clones of eucalyptus. The results of this study can be used to valorize clonal Eucalyptus wood in timber structures and wood industry.
Acta Botanica Malacitana, 2007
ABSTRACT. First record of three species of Pythium from Moroccan waters. Species of Pythium, incl... more ABSTRACT. First record of three species of Pythium from Moroccan waters. Species of Pythium, including P.torulosum, P.catenulatum and P. “Group F”, isolated from dam near Rabat city (capital of Morocco) in northern Africa, are described. Taxonomic and morphological details of the fungi are discussed. This work is the first report of these species from Moroccan waters.Keywords. Antheridia, biodiversity, Morocco, oogonia, Pythium, sporangia.RESUMEN. Primeras citas de tres especies de Pythium para Marruecos. Se describen especies de Pythium, incluyendo P. torulosum, P. catenulatum y P. “Group F”, aislados cerca de la ciudad de Rabat (Marruecos) en el norte de Africa. Se discuten detalles taxonómicos y morfológicos del hongo. Este trabajo es la primera refencia de estas especies en aguas de Marruecos.Palabras clave. Anteridios, biodiversidad, Marruecos, oogonios, Pythium, esporangios.
Journal of the Indian Academy of Wood Science, 2019
The growth stress released during felling trees of Eucalyptus sp. and after cutting into logs cau... more The growth stress released during felling trees of Eucalyptus sp. and after cutting into logs causes fissure and cracks propagation into the log sections. Evolution and velocity of cracks of woody discs of Eucalyptus grandis and E. camaldulensis clones were investigated. The first set of observations and measurements were taken in 2 h after discs crosscutting. All wood discs presented two cracks developed at opposite directions in the transversal plane RT. The discs of E. grandis have larger values for the length and velocity of cracks and energy liberated than those of E. camaldulensis discs. The second set of observations and measurements were done after 2 weeks of discs cutting. In each disc of E. grandis, the two cracks increased towards the periphery. A third crack was appeared in all discs of E. camaldulensis and extended in a perpendicular direction along the two previous cracks. The cracks size increased, and some of them reach the discs periphery with their side opening. In this stage, the wood discs of E. grandis present lower values for splitting indicators than those of E. camaldulensis wood. So, the good knowledge of the cracks evolution related to the growth stress may help us to take the suitable procedures to reduce their influence in this type of wood during cutting, storage and first transformation. In addition, by these findings completed by further researches, mathematical models can be developed in order to increase sawing yield and to avoid splits on woody boards.
Bulletin De La Societe Royale Des Sciences De Liege, May 17, 2011
Dans le but de rechercher des moyens de lutte biologique contre les champignons responsables de l... more Dans le but de rechercher des moyens de lutte biologique contre les champignons responsables de la pourriture des pommes en conservation, des tests de l'activité antifongique des huiles essentielles de Mentha pulegium et d'Eucalyptus camaldulensis ont été réalisés. Les huiles essentielles, obtenues par hydrodistillation, ont été analysées par chromatographie en phase gazeuse couplée à la spectrométrie de masse. L'essence de M. pulegium est dominée par la pulégone (80,28 %), alors que celle d'E. camaldulensis possède le 1,8-cinéole (42,30 %) et l'α-pinène (28,30 %) comme composants majoritaires. Le pouvoir antifongique de ces huiles a été étudié vis-à-vis d'Alternaria alternata et de Penicillium expansum par la technique de micro-atmosphère. C'est l'huile essentielle de M. pulegium qui s'est révélée la plus active, en effet 10 µl de son extrait ont été suffisants pour inhiber totalement la croissance mycélienne des deux moisissures ; alors qu'il a fallut 30 µl d'huile essentielle d'E. camaldulensis pour obtenir le même effet sur les deux champignons. L'effet inhibiteur de ces huiles laisse entrevoir des perspectives d'application dans le domaine de la conservation de certaines denrées alimentaires (pommes, poires, etc.).
Composition chimique, activité antimicrobiennne et antioxydante de l’huile essentielle de Thymus zygis du Maroc
Phytothérapie, 2011
Résumé Ce travail vise l’étude de la composition chimique, de l’activité antioxydante et antimic... more Résumé Ce travail vise l’étude de la composition chimique, de l’activité antioxydante et antimicrobienne de l’huile essentielle (HE) de Thymus zygis du Maroc vis-à-vis de quatre bactéries, de trois moisissures et de quatre champignons de pourriture du bois. Les analyses chromatographiques (CG/FID, CG/SM) ont montré que l’HE de Thymus zygis est caractérisée par la présence du thymol (33,02 %), d’o-cymène (32,02
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Papers by Mohamed RAHOUTI