Arakrak Abdelhay | Université Abdelmalek Essaâdi (original) (raw)

Papers by Arakrak Abdelhay

The chemical composition of essential oil of dry leaves of Teucrium pseudoscorodonia subsp.baetic... more The chemical composition of essential oil of dry leaves of Teucrium pseudoscorodonia subsp.baeticum of North of Morocco from Perdicaris forest was investigated by GC-MS analysis. The detected components were aromatic compounds (12.38 %), oxygenated monoterpenes (7.78 %), fatty acids related compounds (6.91 %), alkaloids (2.12 %), flavonoids (1.82 %), and lactones (0.62 %) and the main components were N-Formylmorpholine (25.07 %), morpholine, 4-acetyl-(17.61 %) and 2-Oxabicyclo[2,2,2]octan-6-one, 1,3,3-trimethyl-(6.47 %).North of Africa houses nearly 1700 species and subspecies endemic, more than 50 % exist only in Morocco. The largest number is in Morocco and Algeria. The herbarium MPU (University of Montpellier 2) have a huge part, followed by the Museum P (National Museum of Natural History, Paris) and RAB (Scientific Institute, Rabat) with respectively 3054, 1059 and 933 exsiccata. Teucrium pseudoscorodonia subsp. Baeticum is an endemic plant of north of Morocco (El Oualidi J. and Khamar H., 2012) and Teucrium is the largest genera of the Lamiaceae in Morocco (Navarro T. and El Oualidi J. 1997. Synopsis of the Genus Teucrium L. (Lamiaceae) In Morocco.Acta Botanica Malacitana 22:187-203). Since the end of XVIII century, different authors have studied this genus;

The presence of mycorrhizal fungi in the rhizosphere of the shrub Cytisus monspessulanus has been... more The presence of mycorrhizal fungi in the rhizosphere of the shrub Cytisus monspessulanus has been studied in three sites in the province of Tangier, northwest of Morocco: R’milat, Boubana and Sloukia. These sites contain large populations of Cytisus monspessulanus.The number of mycorrhizal spores detected in soils collected in the field was relatively high with 3773 spores/100g of soil. Microscopic examination of Cytisus monspessulanus roots has revealed the presence of vesicular-arbuscular-mycorrhizal (VAM) in all samples. Mycorrhizal frequency (F) found in this study was a maximum percentage of 100%.The highest mycorrhizal intensity (M)was observed at the site of Sloukia with 38.62% ,and arbuscular intensity (A) reached 21% in the same site .But the provisional identification test species of VAM, revealed the presence of six genera: Glomus, Acaulospora, Entrophospora, Paraglomus, Septoglomus, Rhizophagus.
Key words: Spore, Tangier, vesicular-arbuscular mycorrhizae, Cytisusmonspessulanus, Glomus.

Pseudomonas fluorescens ET76 was isolated from rice rhizosphere in northwestern Morocco. Its draf... more Pseudomonas fluorescens ET76 was isolated from rice rhizosphere in northwestern Morocco. Its draft genome was estimated to be 6,681,652 bp with 5,789 coding sequences (CDSs). Genes encoding for type I to VI secretion systems, PvdQ, proteases, siderophores, hydrogen cyanide synthase, ACC-deaminase, among others, highlight its potential use in biological control of plant pathogens.

The present study aims to assess the effect of phosphate solubilizing bacteria (PSB) in interacti... more The present study aims to assess the effect of phosphate solubilizing bacteria (PSB) in interaction with native arbuscular mycorrhizal fungi (AMF) and rhizobia on peanut growth cultivated in the Northwest of Morocco. To perform this aim, seeds were inoculated with 5 PSB strains: PP22, GP70, GR1, PR29, and GR70, and then grown in unsterilized soil collected from peanut fields. Plant harvesting was made after 8 weeks of growth under chamber conditions. The results demonstrated that PSB treatments showed positive effect on mycorrhizal colonization, nodulation and plant growth parameters. The best results were found with Pseudomonas strains, GP70, PP22 and GR1. This study indicates the great potential of some PSB to improve yield and nutrient uptake of peanut plants in the presence of native rhizobia and AMF. They could serve as biofertilizers, minimizing chemical fertilization that is currently used to obtain high yields for peanut agriculture. Keywords: AMF, growth, peanut, PSB, rhizobia

Phytothérapie, 2015

ABSTRACT

The catch rates from the Moroccan driftnet fleet targeting swordfish in the Strait of Gibraltar, ... more The catch rates from the Moroccan driftnet fleet targeting swordfish in the Strait of Gibraltar, from 1999Gibraltar, from to 2011 analyzed using the General Linear Modelling approach (GLM), under log-normal error assumption in order to compute standardized abundance indices. The relative abundance index didn't show any clear trend. In general the index showed a relative stable trend over the considered time series. The factors year, month and vessel size explained most of the variability observed in the abundance index. RÉSUMÉ Les taux de capture de la flottille marocaine de filets dérivants ciblant l'espadon dans le détroit de Gibraltar entre 1999 et 2011 ont été analysés au moyen de l'approche de modélisation linéaire généralisée (GLM), en postulant une erreur log-normale afin de calculer les indices d'abondance standardisés. L'indice de l'abondance relative n'a fait apparaître aucune tendance claire. En règle générale, l'indice a dégagé une tendance relativement stable pendant toute la série temporelle considérée. Les facteurs année, mois et taille du navire ont expliqué la plupart de la variabilité observée dans l'indice d'abondance.

Les études d'adsorption et de désorption ont montré dans le cas des rendzines riches en calcaire ... more Les études d'adsorption et de désorption ont montré dans le cas
des rendzines riches en calcaire actif (RDZ1, RDZ2 et RDZ4), que
l'adsorption des ions phosphates ne se fait qu'aux faibles doses
apportées. Aux fortes doses, les ions phosphates précipitent. La RDZ3 et
le pélosol par contre, se comportent différemment. La réversibilité de
l'adsorption des ions phosphates confirme ce que nous avons observé
sur les courbes d'adsorption et ce mécanisme ne se produit qu'aux
faibles doses apportées et surtout dans les RDZ1, RDZ2 et RDZ4.Au
contraire dans le cas du pélosol la désorption est une fonction croissante
du P adsorbé.

Les résultats obtenus pour le phosphore minéral montrent que le phosphore apporté dans les rendzi... more Les résultats obtenus pour le phosphore minéral montrent que le
phosphore apporté dans les rendzines se retrouve lié au calcium sauf
dans le cas de la RDZ3, ou il se partage entre l'aluminium et le calcium.
Par contre dans le cas du pélosol, il se trouve lié au fer et à l'aluminium
Les différentes formes de P minéral dans les rendzines n'ont pas
été modifiées par les apports de paille alors que dans le cas du pélosol
nous avons remarqué un léger effet dépressif de ces apports sur les
formes P-Ca, P-Fe et P-Al et une nette augmentation du phosphore
d'inclusion.
Les résultats concernant le POT nous montrent que les différents
apports n'ont que faiblement modifié les teneurs initiales en POT des sols
étudiés.
Au contraire, l'apport conjugué de la paille et du phosphore semble
maintenir un niveau de POT semblable à celui des sols témoins

L’impact toxicologique des métaux lourds dépend de leur forme chimique, de leur concentration, du... more L’impact toxicologique des métaux lourds dépend de leur forme chimique, de leur concentration, du contexte
environnemental, de la possibilité de passage dans la chaîne trophiquet. A cet effet, notre étude s’est focalisée sur
l’analyse des métaux lourds, sur les échantillons de moule Mytilus galloprovincialis prélevés dans Cinq stations de la
côté méditerranéenne marocaine durant l’été 2007.
Les métaux recherchés sont : Cd, Cr, Pb, Cu, Fe et Zn, en raison de leur taux de toxicité et de leur effet sur
l’environnement ainsi que sur la santé humaine.
L’analyse a été effectuée par spectrophotométrie d’absorption atomique à flamme et à four à graphite.
Les concentrations retrouvées dans les moules se sont avérées faibles avec des teneurs maximales de : 0,02 mg/kg ;
0,85mg/kg ; 0,08mg/kg ; 5,49 mg/kg ; 524,03 mg/kg et 28 mg/kg ; respectivement pour le Cd, Cr, Pb, Cu, Fe et Zn.
Globalement l’analyse des résultats a montré que la teneur en métaux de tous les échantillons se situant au dessous
des valeurs guides des teneurs métalliques autorisées à l’échelle européen et ne sont pas significativement contaminés
par les métaux.
Mots Clés: Mytilus galloprovincialis, métaux lourds, S.A.A., métaux essentiels, pollution, méditerranée

Among 65 LAB were screened for exhibition of antagonistic activities using agar well diffusion me... more Among 65 LAB were screened for exhibition of antagonistic activities using agar
well diffusion method. It was found that 40 isolates exhibited antibacterial activity
against Listeria monocytogenes, including 35 strains displayed large inhibition
spectra results in excellent inhibition zones diameters larger than 15 mm. Of these,
8 strains (LBA01, LBA07, LBA09, LBB08, LBC02, LBC04, LBD02, and LBD05)
were also active against Gram-negative bacterium Escherichia coli O157 and were
identified as Enterococcus faecium. Results showed that the LAB strains retained
activity in the supernatants after effects of organic acid and hydrogen peroxide
were eliminated. It was determined that the bacteriocins produced by both strains
Enterococcus faecium LBB08 and Enterococcus faecium LBC02 that have been
purified by the method of Yang were active towards Listeria monocytogenes and
Escherichia coli O157. This result suggests the possibility to use the strains studied
as a natural substance for microbiological control in a variety of industrial
applications.
Ke ywo rds
Table olive
brines,
Enterococcus
faecium,
Antimicrobial
activity,
Food
preservation

The present work had two objectives: the first, to compared the total phenolic contents (using Fo... more The present work had two objectives: the first, to compared the total phenolic
contents (using Folin Ciocalteu s reagent) and antioxidant activity (using three
different in vitro test assays) of three Mentha species and second, to determine
whether these parameters changed with change of solvents extract polarity. Mentha
spicata, Mentha pulegium and Mentha piperita were successively extracted with
solvents of increasing polarity (n-hexane, dichloromethane (DCM), methanol and
distilled water) using a soxhlet extractor. Our results reported that water and
methanol (polar solvents) extracts, which contained the highest amount of total
phenolic contents exerted strong reducing power and scavenging DPPH radical
activity, which are almost equal to positive control BHT. Hexane and DCM (non
polar solvents) extracts were showed a negligible antioxidant activity with both of
test assays. Thus, the results indicate that polar solvents were important for
obtaining fractions with high antioxidant activity and total phenolic content. All
extracts tested in this study were found to be moderate in antioxidant capacity in
the -carotene/linoleic acid test assay and none of the extracts showed activity as
strong as BHT. A positive correlation was found between total phenolic level and
DPPH radical scavenging (r2 = 0.82) and reducing power (r2 = 0.86) assays.
Whereas, there was no correlation (r2 = 0.25) between phenol contents and -
carotene/linoleic acid assay.
Ke ywo rds
Antioxidant
activity,
Total
phenolic
content,
Mentha
species,
Polar solvent
extracts,
Non-polar
solvent

Ce travail est une étude de caractérisation de la biodisponibilité du phosphore de cinq sols calc... more Ce travail est une étude de caractérisation de la biodisponibilité du
phosphore de cinq sols calcimorphes après apport ou non de phosphate
diammonique et de paille de riz a été caractérisée par des cinétiques de
dilution isotopique. Les résultats montrent que les apports de P diminuent le
pouvoir fixateur (augmentation de R1/R0) et augmentent leur biodisponibilité par
les plantes. Les apports de paille augmentent aussi le rapport R1 /R0 dans la
RDZ1, RDZ3 et le pélosol (donc une diminution du pouvoir fixateur), et
diminuent, par contre, la valeur de M1 et E(t) dans la RDZ2, RDZ4 et le pélosol.
Mots-clés : Biodisponibilité du phosphore, Sols, Phosphate diammonique, Paille de riz, Cinétiques de dilution isotopique

Ce travail présente l’étude de la solubilisation de phosphate tricalcique par des Rhizobium isolé... more Ce travail présente l’étude de la solubilisation de phosphate tricalcique
par des Rhizobium isolés des nodules de trois légumineuses
(Hydesarum coronarium, Vicia sativa, et Lupinus angustifolius), et tester leur
effet sur la germination des semences du triticale, variété Momtaz.
Dans un premier temps, les 53 isolats obtenus ont été testés sur milieu
PVK solide renfermant 0,5% de phosphate tricalcique (PTC), afin de garder
ceux ayant l’activité solubilisatrice de PTC. Ainsi, six isolats (H2-7, H2-10, H3-5,
L1, L2 et L5) ont donné des halos de solubilisation de diamètre oscillant entre
0,3 cm et 0,6 cm. Par la suite, ces isolats ont été soumis au test quantitatif dans
le milieu PVK liquide en mesurant le P solubilisé et le pH. Les résultats obtenus
sont compris entre 9,62 mg/L et 158,64 mg/L de P respectivement par H3-5 et
L1. Cette dissolution biologique de phosphore inorganique est accompagnée
par une diminution de pH du milieu, et l’intensité de cette acidification diffère
d’un isolat à l’autre.
Enfin, les résultats de l’inoculation montrent une diminution par rapport
au témoin, aussi bien pour la germination que pour la matière sèche, sauf
l’augmentation de 16,66% obtenue en présence de l’isolat H3-5.
Mots Clés : Rhizobium, Phosphate tricalcique, Légumineuses, Germination,Triticale

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Morocco is poorly docum... more The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Morocco is poorly documented. The aims of the prospective study were to describe the incidence, microbiologic profiles of patients with both methicillin-sensitive S.aureus (MSSA) and MRSA, and to investigate the prevalence of Staphylococcus aureus infections carrying Panton-Valentine leukocidin (LPV) genes. From August 2008 to August 2011, eighty S. aureus were collected at the trauma service of Tangier’s Mohamed V Provincial Hospital. Bacterial identification was based on standard methods and susceptibilities were tested by disk diffusion method. MICs to vancomycin were determined by the broth microdilution. Molecular study (16S RNA, nuc, mecA, and toxin PVL) was determined by multiplex PCR. Multiplex PCR analysis showed that mecA gene was present in 8 (10%) of 80 S. aureus. MRSA were predominantly multiantibiotic-resistant hospital-acquired. We noted a high resistance to fluoroquinolones, fusidic acid and tetracycline by 100%, 75%, and 75% respectively. Decreased susceptibility to vancomycin was not detected. 10% of the S. aureus isolates carried genes for LPV. Epidemiological data identified that PVL was associated with truly community-acquired disease CA-MSSA (p<0.001), younger age (p<0.05) and presentation with skin and soft-tissue infections (p<0.001). Compared with various countries of the world, our results show a low rate of MRSA and MSSA PVL positive. However, given the genetic plasticity of this species, caution is required and a monitoring system must be set up.
Key words: MRSA; MSSA; LPV; Community-acquired; Hospital-acquired.

Agriculture provides the main income for the economy in Mediterranean countries. Morocco, a North... more Agriculture provides the main income for the economy in Mediterranean countries. Morocco, a North African and Mediterranean country, surrounded by the Mediterranean Sea and Atlantic Ocean, is characterized by a hot and humid climate which could probably lead to mold contamination and mycotoxin production especially in coastal areas.
This contribution gives an overview of the contamination by fungal mycoflora of cereals and coffee consumed in the North of Morocco .Some species belonging to the genus Aspergillus that are known to be a potential producers of ochratoxin A(OTA), this mycotoxin has been shown to be a nephrotoxic, hepatotoxic, teratogenic and possibly carcinogenic for humans.
The aim of the present work was to know the fungal distribution in some crops collected in northern Morocco, Tangier city. The species of saprophytic fungal were identified including Aspergillus and Penicillium that contaminate wheat, rice and coffee beans. Studies on fungal DNA detection in 88 fungal samples have been performed. They were identified at the species level, by sequencing the internal transcribed spacer (ITS4, ITS5) of ribosomal DNA (rDNA). This is the first report on the contamination by mycotoxigenic fungi in coffee from Morocco, and also there is no previous work exists on contamination by these fungi in cereals samples from North of Morocco.
Keywords: Fungal mycoflora, Aspergillus, Penicillum, rDNA, ITS, cereals, coffee, Morocco.

The objective of this study was to compare the effect of dietary fennel and thyme essential oil s... more The objective of this study was to compare the effect of dietary fennel and thyme essential oil supplementation with the effect of antibiotic on zootechnical parameters and caecal microflora of rabbits. 40 weaned rabbits (35 days old), white New Zealand, were divided into two groups and submitted to two dietary treatments: EOFT (diet with essential oil of Feoniculum vulgaris and Thymus capitatus) and OTC (diet with oxytetracycline in drinking water). The application of fennel and thyme essential oil had a beneficial effect on the mortality. The mean carcass yield of OTC group was higher than EOFT group after twenty five days of the treatment. However, the difference of dietary fennel and thyme essential oil supplementation and oxytetracycline on live weight, growth rate and feed conversion ratio were not significant. No difference was found on caecal count of E.coli and C.perfringens in both treated groups.
Key words: Essential oil, oxytetracycline, growth performance, rabbit

The objective of this study was to evaluate the effect of fennel and thyme dietary supplements on... more The objective of this study was to evaluate the effect of fennel
and thyme dietary supplements on the feeding of rabbits. Eighty-five weaned
rabbits (35 days old), white New Zealand (of both sexes), were divided into
four groups and submitted to the following dietary treatments: Control diet, diet
F (Control diet + 2.5% Foeniculum vulgare seeds), diet T (Control diet + 2.5%
Thymus capitatus leaves) and diet FT (Control diet + 2.5% Foeniculum vulgare
seeds and Thymus capitatus leaves) for twenty-five days. The treatment with
fennel and thyme had a beneficial effect on the mortality rate (18%). However
the growth rate, feed conversion ratio and carcass yield were not influenced by
dietary fennel and/or thyme supplementation. The antimicrobial effect of thyme
(2.5%) was observed only against C. perfringens in the caecum (P < 0.05), but
no effect was observed on the caecal count of or C. perfringens in the other
treated groups.
KEY WORDS: rabbit, fennel, thyme, growth
parameters, caecal microflora

The objective of this study is to evaluate the effect of condensed tannins (CTs) distribution usi... more The objective of this study is to evaluate the effect of condensed tannins (CTs) distribution using
carob pulp in diet on meat and carcass quality and growth performance of kids. Three diets with 0%, 25%,
and 45% of carob pulp (C0, C5 and C10, respectively) were distributed to 3 groups of kids from weaning to
slaughter at 6 months of age. C5 kids showed highest ADG90-180 and final weight at 180 days (73.33 g/day;
18.50 kg respectively). Meat moisture, fat, pH and water retention showed no variation. However, C5
contains more protein (P<0.05).The linoleic acid composition in meat increase with C10 (P<0.05). The low
intakes of CTs seem to be insufficient to fully protect certain unsaturated fatty acids against biohydrogenation
of fatty acids (DFA 67.03% vs 64.91% and 66.54% respectively for C0, C5 and C10,
P>0.05). The same result was observed for perirenal fat. Omega 6 and C18:1n9 experienced an increase in
meat from goats fed with the C10 diet (P>0.05). Carob use in kids diet is accompanied by an improvement
of protein and desirable fatty acids, especially linoleic acid, in meat.

Phytothérapie, 2015

ABSTRACT

To study the diet of the swordfish (Xiphias gladius) in the Strait of Gibraltar, a total of 176 s... more To study the diet of the swordfish (Xiphias gladius) in the Strait of Gibraltar, a total of 176 stomachs were examined from the Moroccan artisanal fishery targeting this species, from April to September 2015. The frequency of occurrence (FO), percentage in number and in weight of prey as well as the per cent index of relative importance of prey (%IRI) were calculated to assess the diet preferences of swordfish in relation to its body size, sex and month. Our findings confirm the opportunistic feeding behaviour of swordfish. The prey items consist primarily of fish (54.6% in number and 82.7% in weight), followed by cephalopod (43.36% in number and 17.25% in weight). The Atlantic horse mackerel (Trachurus trachurus) and the southern shortfin squid (Illex coindetii) are the most important prey, with a % IRI of 47.54 and 35.04%, respectively. The results revealed that there are no significant differences in the diet preferences among sexes and size classes. However, diet composition varied significantly among months. A significant correlation was found between the body length of predator and prey size. The remarkable decrease in the fullness index (fi) from June to August suggests that swordfish were in a spawning condition, with reduced feeding.

High content of condensed tannins (CT) in diet affect the growth and quality of the goat meat. Th... more High content of condensed tannins (CT) in diet affect the growth and quality of the goat meat. This ef-

fect can be negated by the addition of polyethylene glycol (PEG). Three doses of PEG (0, 10 and 20 g/day/kid)

were administered respectively to 3 groups of growing kids (0PEG, 10PEG and 20PEG) receiving 75 g/kid/day

of CT from Ceratonia siliqua. The results showed that PEG doses proved to be insufficient to improve significantly

both growth performance and the quality of the meat. The 10PEG and 20PEG doses caused a significant de-

crease in Omega 3 fatty acids (-49.6% and -5.7%), desirable (-10.6% and -9.9%), unsaturated (-18.0 % and -13.9%),

monounsaturated (-19.6% and -34.4%) and polyunsaturated (-19.2% and -3.4%) and long chain (-7,7% and -

8.3%). There were no significant effects of PEG on the weight at 180 days of age (13.9 vs15.21 and 13.81 kg)

GMQ 90-180 (31.89 vs33.56 and 25.44 g) and the cold carcass weight of the (5.80 vs6.74 and 5.21 kg), respec-

tively, for 0, 10 and 20PEG, as well as the content of meat protein and fat. Lower doses of 10PEG to CT or other

processing techniques must be tested to mitigate the CT inhibitory effect on growth and meat quality
Keywords. Goat – PEG – Condensed tannins – Meat

Diets containing high levels of condensed tannins (CT) can alter the production and quality of go... more Diets containing high levels of condensed tannins (CT) can alter the production and quality of goat

milk. This effect can be negated by the addition of polyethylene glycol (PEG). Three doses of PEG (0, 20 and

40 g/day/goat) were administered respectively to three groups (0PEG, 20PEG and 40PEG) of lactating goats.

Ten goats in each group receive 75 g/head/day of CT from carob pulp. The results show that the 20PEG dose

increases milk production by +31.5% (95.76 vs72.81 and 70.21 kg/120 day of lactation/goat for respectively

20 and 0 and 40PEG). The content of desirable fatty acids, unsaturated fatty acids and monounsaturated in

milk increased with 20PEG treatment [+20%, respectively (46.56% vs38.75%, P<0.05); +73% (37.03% vs

21.43%, P<0.001) and +110% (26.15% vs 12.43%, P<0.001)] and decreased for undesirable saturated fatty

acids [-20% (62.96% vs78.57%, P<0.001)]. It should be noted that the highest dose (40PEG) has lowered milk

production by 4% (P<0.001), without this being attributable to amounts of tannins present. Under conditions

where it is feared the presence of CT, it is imperative not to exceed the dose of 20 g PEG/day/goat. If the tan-

nins were more abundant (>10% DM), we should try to dilute CT with changing fodder regime.

Keywords. Milk – Goat – Condensed tannins – PEG

The main purpose of this work was the characterization of the biochemical changes during storage ... more The main purpose of this work was the characterization of the biochemical changes during storage

goat meat in northern Morocco. Seven goats were used in this study. They were slaughtered according to Is-

lamic rite. The temperature, pH, water retention capacity and electrical conductivity were determined. The re-

sults showed a significant decrease (P<0.05) in pH during the post-mortem time and significant augmentation

(P<0.05) in water retention and the electrical conductivity. There is no different between the types of muscle.

Most changes were observed within 24 hours post mortem.

Keywords.Goat meat – Temperature –Post mortem.

Environmental and microb. Biotechnology2020

Due to high cost of chemical fertilizers and negative environmental effects, the use of rhizobia ... more Due to high cost of chemical fertilizers and negative environmental effects, the use of rhizobia as plant growth-promoting rhizobacteria (PGPR) has shown potentials to be a promising technique to assure a sustainable agriculture. Our goal was to select rhizobia strains isolated from nodules of Hydesarum pallidum plants present in Touissit, northeast of Morocco, exhibiting different activities that can stimulate directly and/or indirectly plant growth. A total of 37 bacteria were isolated, of which 19 were capable of solubilizing tricalcium phosphate (TCP). Based on the diameter of solubilization halos (diameter ≥0.4 cm), 15 strains were selected and evaluated for more PGP activities in vitro for selected isolates. As a result, 11 bacteria were proved to be able to synthesize hydrogen cyanide (HCN). Amounts of indole acetic acid (IAA) produced by these bacteria ranged between 1.04 and 3.43 mg L⁻¹. Their ability to secrete siderophores was also evaluated; 80% of the strains were positive for these compounds’ production. We also looked for extracellular enzymes such as cellulase, amylase, protease, chitinase, and urease. The percentages of bacteria that were positive for the production of these hydrolytic enzymes were, respectively, 73.3%, 93.3%, 40%, 26.67%, and 33.3%. Eight of selected bacteria were checked for quantitative assay of TCP solubilization, and soluble P concentrations were between 2 and 137 mg/L, accompanied by a drop in media pH from 5.67 to 3.87. This study reveals the potential of some rhizobia to be used as efficient biofertilizers.

Phyto-Microbiome in Stress Regulation, 2020

This study aims to describe the endomycorrhizal status of Hedysarum pallidum Desf. in the northea... more This study aims to describe the endomycorrhizal status of Hedysarum pallidum Desf. in the northeast of Morocco. A detailed description of the mycorrhizal associations in this species soil and roots is reported for the first time in this study. To achieve this goal, some tests were run on soil and root sample collected from the rhizosphere of Hedysarum pallidum Desf. The microscopic examination of the roots revealed the presence of typical endomycorrhizal structures. The mycorrhizal frequency was greater than 98%, the mycorrhizal intensity was high (50.9%), and the arbuscular intensity reached 34.76%. The spore number of the arbuscular mycorrhizal fungi (AMF) isolated from the soil was 1200 spores/100 g of soil. These spores presented three AMF genera: Glomus, Scutellospora, and Septoglomus. The diversity of arbuscular mycorrhizal fungi present in the rhizosphere can be selected and used in improving the production of vigorous plants.

In book: Phyto-Microbiome in Stress Regulation, 2020

In vitro screening of plant growth-promoting (PGP) traits was carried out using 63 Pseudomonas, i... more In vitro screening of plant growth-promoting (PGP) traits was carried out using 63 Pseudomonas, isolated from the rhizosphere of Lotus creticus collected from the northwest region of Morocco. The isolates were tested for their capacity of solubilizing tricalcium phosphate (TCP) on Pikovskaya (PVK) solid medium, and 20 Pseudomonas could solubilize TCP. We then selected five phosphate solubilizing bacteria (PSB) based on their halo diameters to undergo more tests. As a result, all five isolates were positive for hydrogen cyanide (HCN) production, and the amount of indole acetic acid (IAA) produced by them fluctuated between 5.72 ± 0.09 mg/L and 195.16 ± 0.38 mg/L. All the selected strains could produce siderophores. Except urease activity, all isolates possessed at least two enzyme activities such as cellulase, chitinase, protease, and amylase activities. In addition, all these PSB were able to produce ammonia. Thus, the strains were evaluated by TCP solubilizing quantitative assay in PVK liquid medium. The concentrations of solubilized P were between 20.80 mg/L and 159.55 mg/L. This solubilization was accompanied by a pH decrease of the medium from 7 to 4.16. Furthermore, the five PSB were tested in vitro for antagonism against phytopathogenic fungus Fusarium oxysporum, and all the PSB except LCP18 strain were capable of inhibiting its growth.

In book: Phyto-Microbiome in Stress Regulation, 2020

Phenotypic characteristics of 69 rhizobial strains isolated from root nodules of Cytisus monspess... more Phenotypic characteristics of 69 rhizobial strains isolated from root nodules of Cytisus monspessulanus leguminous shrub growing in soils collected from the northwest of Morocco were studied. Tolerance to salinity, high temperatures, acid and alkaline pH, heavy metals, carbon and nitrogen source assimilation, and symbiotic and cultural characteristics allowed the description of a wide physiological diversity among tested isolates. Numerical analysis of the phenotypic characteristics showed that below the boundary level of 48, 91% of average similarity isolates fell into at least four distinct groups. A number of potential isolates have been identified for inoculation trials. They were efficient and able to form nodules with indigenous rhizobia in this region.