Biofertilizers are a key component of organic agriculture. Bacterial biofertilizers enhance plant growth through a variety of mechanisms, including soil compound mobilization and phosphate solubilizing bacteria (PSB), which convert insoluble phosphorus to plant-available forms. This specificity of PSB allows them to be used as biofertilizers in order to increase P availability, which is an immobile element in the soil. The objective of our study is to assess the capacity of PSB strains isolated from phosphate solid sludge to solubilize three forms of inorganic phosphates: tricalcium phosphate (Ca₃(PO₄)₂), aluminum phosphate (AlPO₄), and iron phosphate (FePO₄), in order to select efficient solubilization strains and use them as biofertilizers in any type of soil, either acidic or calcareous soil. Nine strains were selected and they were evaluated for their ability to dissolve phosphate in the National Botanical Research Institute’s Phosphate (NBRIP) medium with each form of phosphate (Ca₃(PO₄)₂, AlPO₄, and FePO₄) as the sole source of phosphorus. The phosphate solubilizing activity was assessed by the vanadate-molybdate method. All the strains tested showed significantly (p ≤ 0.05) the ability to solubilize the three different forms of phosphates, with a variation between strains, and all strains solubilized Ca₃(PO₄)₂ more than FePO₄ and AlPO₄.

This study focused on revealing the correlations between rock phosphate-solubilizing bacteria (PSB) counts and differing properties of the rhizosphere soil. One hundred and thirty-two samples of rhizosphere soil of faba bean (Vicia faba L.) were collected and analyzed from 14 agricultural areas in Meknes, Morocco. The results revealed that all the samples were inhabited with indigenous PSB ranging from 3.55 to 0.002 (×10⁵ CFU/g soil). The correlations between PSB counts and cation exchange capacity, available phosphorus (P), and pH were insignificant; on the contrary, a highly significant correlation (p ≤ 0.01) was found between the numbers of PSB and total soil bacteria (TB) (r = 0.80), total nitrogen (N) (r = 0.86), and organic matter (r = 0.90). This research enhances our knowledge on PSB population and their interaction with physical, chemical, and biological properties of the rhizosphere soil of faba bean to provide a new index for better use in organic agricultural practices.

Valorisation du lentisque « Pistacia lentiscus L. »: Étude ethnobotanique, Screening phytochimique et pouvoir antibactérien

Background: Soil microorganisms are exposed to herbicides after treatment, which leads to their interaction. The result of this interaction may be the degradation of the herbicides by the microorganisms and by the way, they use the degradation products as an energy source for their own physiological processes, or herbicides have a toxic effect on these microorganisms. Herbicide toxicity becomes severe instantly after application when its concentration in soil is the highest. Paraquat is one of the most widely used herbicides in agriculture; inappropriate use of this herbicide represents an immense pollution problem for soil, therefore on microorganisms. However, the knowledge about the effect of paraquat on soil microorganisms has been limited.Objectives: The purpose of the current study was to determine the effect of paraquat application on four nitrogen-fixing bacteria:Pantoea agglomerans, Rhizobium nepotum, Rhizobium tibeticumandRhizobium radiobacter.Methods: Paraquat was applied as the sole source of carbon at a rate (0 g/L, 0.5 g/L, 1 g/L, 3 g/L, 6 g/L and 12 g/L). The effect of paraquat treatments was determined by agar diffusion method and the rate of the growth of bacterial colonies in each treatment.Results: In the agar diffusion method, the bacterial strains were inhibited by paraquat, in which the inhibition zone was wider with the increase of paraquat concentration; also, analysis of the Colony Forming Units (CFUs) mostly showed a declining in bacterial growth. In comparison with the control, the growth of the four strains was decreased by increasing the paraquat concentration. Comparing strains with each other,Pantoea agglomeransis the most resistant strain to paraquat.Conclusion: Our study has shown the impact of the irrational use of pesticide upon the beneficial bacteria in question. For that, the results of this research have a positive impact on the natural environment, which will have tangible social and economic impacts.

Morocco is a significant botanical reservoir that boasts a wealth of raw materials with promising applications across various industrial sectors, notably in pharmaceuticals and food. The objective of this study was to assess the effectiveness of essential oils (EOs) derived from Laurus nobilis L. leaves originating from the Tanger (EOT) and Meknes (EOM) regions in combating Callosobruchus maculatus infection. The chemical compositions of these oils were examined using Fourier transform infrared (FTIR) spectroscopy and gas chromatography–mass spectrometry (GC-MS). The biological activity of the EOs was evaluated via repulsion and fumigation tests against C. maculatus at varying concentrations. FTIR analysis revealed distinct vibrational bands indicative of various chemical compounds. GC-MS analysis was used to delineate the major chemical constituents of the EOs. The three predominant compounds in the EOT were 1,8-cineole (37.64%), linalool (16.40%), and adamantane (12.00%), whereas 1,8-cineole (47.84%), toluene (17.60%), and α-phellandrene (8.44%) were the most abundant in the EOM. Notably, the EOs exhibited significant repellent activity against C. maculatus, with repulsion percentages ranging from 51.11 to 90.00% in Tanger and 67.78 to 93.33% in Meknes. Mortality rates varied from 0 to 100% depending on the treatment. However, the mean concentrations showed mortality rates ranging from 29.44 to 65.56% for the EOT and from 21.11 to 67.78% for the EOM, with LD50 values of 11.96 μL/L and 5.22 μL/L. Docking studies revealed that 1,8-cineole had the highest binding affinity for the active site of acetylcholinesterase, thus confirming its toxic activity against C. maculatus. The findings of this study highlight the ability of EOs extracted from L. nobilis in the Moroccan regions of Tanger and Meknes to act as effective insecticides and repellents against C. maculatus, thereby highlighting avenues for further exploration of pest management and agricultural practices.