The Juglans regia root aqueous extract (JRRAE) phytochemical variability and the investigation of their antimicrobial, antibiofilm, insecticidal, and anti-leishmanial properties were studied. As a result, the JRRAE chemical profile revealed the presence of biomolecules using UV, HPLC, and FT-IR analysis. The investigations showed marked antibacterial activities, highlighted inhibited biofilm formation, induced lethality Leishmania amazonensis promastigotes (50%), and possess an insecticidal activity at 100 µg/ml. A molecular docking study was performed against S. aureus gyrase, S. aureus tyrosyl-tRNA synthetase, human peroxiredoxin 5, cyclooxygenase-2, and trypanothione reductase and confirmed that the activities are mainly due to coumarin, epicatechin, juglone, epicatechin, and epicatechin presence, respectively. The stability of these complexes is essentially related to the strong hydrogen bonds formed between the most active compounds and the binding site amino acids. The identified compounds were found to pass the absorption, distribution, metabolism, and excretion property as well as five Lipinski’s rules with good drug-likeness and pharmacokinetic behavior.

In the present study, polysaccharides were isolated from the leaves (WSPRaL) and stems (WSPRaS) of Rhamnus alaternus with yields of 3% and 3.25% for WSPRaS and WSPRaL, respectively. Crude WSPRaL was composed of proteins (260.740 ± 0.98 µg/mg), lipids (53.34 ± 2.38 µg/mg), total sugars (482.716 ± 3.02 µg/mg), and reducing sugars (420.240 ± 1.68 µg/mg). In contrast, WSPRaS contained proteins (269.629 ± 1.48 µg/mg), lipids (13.33 ± 0.28 µg/mg), total sugars (569.135 ± 3.82 µg/mg), and reducing sugars (531.732 ± 2.59 µg/mg). FTIR, TLC, and HPLC analyses revealed that the carbohydrate fraction of WSPRaS consisted mainly of glucuronic acid, glucose, galactose, xylose, mannose, and arabinose, whereas WSPRaL consisted of galacturonic acid, sucrose, glucose, rhamnose, xylose, mannose, and arabinose. Scanning electron microscopy (SEM) analysis was used to determine the microstructure of the water-soluble polysaccharides. The physicochemical properties were evaluated using Fourier transform infrared (FT-IR) spectroscopy and ultraviolet‒visible (UV‒visible) absorption spectroscopy. The total antioxidant activities of the crude polysaccharides were evaluated using various assays: DPPH radical scavenging (IC₅₀ WSPRaL = 615 ± 2.05 µg/mL, IC₅₀ WSPRaS = 628 ± 2.38 µg/mL), ABTS radical scavenging (470 ± 5.78 µg/mL and 559 ± 4.32 µg/mL for WSPRaL and WSPRaS, respectively), reducing power (IC₅₀ WSPRaS = 141.76 ± 3.16 µg/mL, IC₅₀ WSPRaL = 203.89 ± 1.07 µg/mL), and chelating capacity (IC₅₀ WSPRaS = 225 ± 1.75 µg/mL, IC₅₀ WSPRaL = 219 ± 2.51 µg/mL). In addition, the antibacterial and biofilm inhibitory activities of both polysaccharides were tested against pathogenic strains, and the polysaccharides significantly inhibited plant growth. Overall, the results indicate that the crude polysaccharides extracted from R. alaternus are promising for use as functional and bioactive ingredients in the food and nutraceutical industries. These results highlight the potential of both polysaccharides as natural products in various sectors, including food, cosmetics, pharmaceuticals, and medicine, due to their significant biological properties.

The aim of the present study is to isolate, characterize and identify a novel strain ZC from the Metlaoui phosphate laundries wastewater (MPLW). The chemical characterization of this phosphate rich effluent showed an alkaline pH and is saline, highly turbid and rich in suspended matter and total solids. The MPLW samples were loaded with potentially toxic metals, presented in decreasing order as follows: magnesium (5655 mg L⁻¹), potassium (45 mg L⁻¹), lead (1 mg L⁻¹), iron (0.7 mg L⁻¹), cadmium (0.5 mg L⁻¹), copper (0.3 mg L⁻¹) and zinc (0.1 mg L⁻¹). Due to the high COD/BOD₅ ratio, a poorly biodegradable organic load is underlining. The newly isolated strain was identified as Lysinibacillus fusiformis using 16S rDNA sequencing analysis. The viability of this new strain was tested in presence of the zinc, lead, cadmium, manganese and copper at 1, 10 and 100 mM. The L. fusiformis survival, under metallic stress, was inversely proportional to metal ion concentrations, while lead and zinc were the most toxic ones using MTT assay. Then, the newly isolated strain was characterized in terms of enzyme production, proteomic alteration and antibiotic resistance. The strain ZC revealed some modifications in the biochemical and enzymatic profiles by either the appearance or/and the disappearance of some activities. In addition, the increase in metal ions stress and concentrations was proportional to the adherence and to the hydrophobicity. The presence of the metal ions suggested the change of sensitivity to the resistance of this strain towards tobramycin, kanamycin, neomycin, netilmicin and cefoxitin, showing an increase in the MAR_index. The strain ZC, used as a biological tool for MPLW treatment, showed a reduction in the metal ion contents. This reduction was due to accumulation and/or adsorption, showing a bioprocessing performance of the newly isolated L. fusiformis.

Soil contamination by heavy metals through the application of a phosphate fertilizer is a key issue for sustainable agriculture. Among contaminants, cadmium (Cd) is considered the most hazardous to human beings’ health and the surrounding environment. X-ray diffraction (XRD), combined with binocular mineralogical analysis and chemical analysis, was used to determine the C(I) and C(II) layers’ composition. In the C(II) (+71 µm)-size fraction, the presence of carbonate-fluorapatite, illite, and montmorillonite was revealed, whereas in the C(I) (−71 µm)-size fraction, carbonate-fluorapatite, calcite, quartz, sanidine, clinoptilolite, and taramovite were identified. The P₂O₅ and CaO contents were greater in the C(II) layer than that in the C(I) layer, whereas SiO_2, MgO, CO₂, Cd, Zn, and CO_rg were higher in the C(I) layer than that in the C(II) layer. The bioleaching of Cd from phosphate rock samples from the Kef Eddour deposit was investigated using three bacterial strains isolated from the local phosphate environment. A decrease in cell viability was noticed when the phosphate C(I) and C(II) samples showed toxicity in the samples. In addition, the isolated bacteria, which were initially moderately hydrophobic, changed to strongly hydrophobic. The use of the consortium (S1 + S2 + S3) was the most powerful combination to reduce the Cd content, which increased from 13.31% to 29.07% using S3 and the consortium (S1 + S2 + S3), respectively, when the C(II) (+71 µm)-size fraction sample was added to the medium. The same result was shown when the C(I) (−71 µm)-size fraction sample was used. The isolated strains could be used as a biological tool for bioleaching.

In this study, we incubated four strains of Shigella in seawater microcosms (at room temperature and at 4°C) for eight months and we studied the alteration of their morphologic and outer membranes proteins. The starved cells showed an evolution to the filterable minicells state capable to pass membrane pore size 0.45 µm. In addition, the atomic force micrographs showed a reduction of the cells size and an evolution to coccoid-shapes. Outer membrane proteins patterns of stressed bacteria did not changed too much and these modifications were manifested by the appearance of one new band. Key words: Shigella, seawater, starvation, morphological, outer membrane proteins.