In the presented study, Bacillus subtilis strain AG4 isolated from marine was identified based on morphological, physiological, phylogenetic characteristics and an examination of 16S rRNA sequences. Novel exopolysaccharide (EPSR4) was extracted and isolated from the Bacillus subtilis strain as a major fraction of exopolysaccharide (EPS). The analysis of structural characterization indicated that EPSR4 is a β-glycosidic sulphated heteropolysaccharide (48.2%) with a molecular weight (Mw) of 1.48 × 10⁴ g/mole and has no uronic acid. Analysis of monosaccharide content revealed that EPSR4 consists of glucose, rhamnose and arabinose monosaccharide in a molar ratio of 5:1:3, respectively. Morphological analysis revealed that EPSR4 possess a high crystallinity degree with a significant degree of porosity, and its aggregation and conformation in the lipid phase might have a significant impact on the bioactivity of EPSR4. The biological activity of EPSR4 was screened and evaluated by investigating its antioxidant, cytotoxicity, anti-inflammatory, and anti-Alzheimer activities. The antioxidant activity results showed that EPSR4 has 97.6% scavenging activity toward DPPH free radicals at 1500 µg/mL, with an IC₅₀ value of 300 µg/mL, and 64.8% at 1500 µg/mL toward hydrogen peroxide free radicals (IC₅₀ = 1500 µg/mL, 30 min). Furthermore, EPSR4 exhibited considerable inhibitory activity towards the proliferation of T-24 (bladder carcinoma), A-549 (lung cancer) and HepG-2 (hepatocellular carcinoma) cancer cell lines with IC₅₀ of 244 µg/mL, 148 µg/mL and 123 µg/mL, respectively. An evaluation of anti-inflammatory activity revealed that EPSR4 has potent lipoxygenase (LOX) inhibitory activity (IC₅₀ of 54.3 µg/mL) and a considerable effect on membrane stabilization (IC₅₀ = 112.2 ± 1.2 µg/mL), while it showed cyclooxygenase (COX2) inhibitory activity up to 125 µg/mL. Finally, EPSR4 showed considerable inhibitory activity towards acetylcholine esterase activity. Taken together, this study reveals that Bacillus subtilis strain AG4 could be considered as a potential natural source of novel EPS with potent biological activities that would be useful for the healthcare system.

The rise of multidrug-resistant pathogens has intensified the need for eco-friendly antimicrobial alternatives. In this study, silver nanoparticles (AgNPs) were synthesized using extract of Fumaria indica , an ethnomedicinal plant rich in bioactive compounds. The successful synthesis of FI@AgNPs was confirmed by a color change and a characteristic UV–Vis absorption peak at 409 nm. XRD analysis revealed a face-centered cubic (fcc) crystalline structure with an average crystallite size of 22.09 nm, while SEM and EDX confirmed spherical morphology and high silver content. The synthesized nanoparticles (NPs) exhibited good antibacterial activity against both Gram-positive and Gram-negative bacteria, with maximum inhibition observed against Streptococcus mutans and Staphylococcus epidermidis . Sensitivity was shown by minimum inhibitory concentration (MIC) values for the Gram-positive strain getting as low as 20 µg/mL. Significant antifungal activity was also noted against Candida albicans and Aspergillus flavus . Furthermore, FI@AgNPs demonstrated enhanced antioxidant potential in both DPPH and FRAP assays, exceeding the activity of the crude extract. These findings suggest that FI@AgNPs possess broad-spectrum antimicrobial and antioxidant properties, making them promising candidates for biomedical and pharmaceutical applications. This study reinforces the value of plant-based nanotechnology in developing effective alternatives to conventional therapeutics.

Waste cooking oil is a common byproduct in the culinary industry, often posing disposal challenges. This study explores its conversion into the valuable bioplastic material, medium-chain-length polyhydroxyalkanoate (mcl-PHA), through microbial biosynthesis in controlled bioreactor conditions. Twenty-four bacterial isolates were obtained from oil-contaminated soil and waste materials in Mahd Ad-Dahab, Saudi Arabia. The best PHA-producing isolates were identified via 16S rDNA analysis as Neobacillus niacini and Metabacillus niabensis, with the sequences deposited in GenBank (accession numbers: PP346270 and PP346271). This study evaluated the effects of various carbon and nitrogen sources, as well as environmental factors, such as pH, temperature, and shaking speed, on the PHA production titer. Neobacillus niacini favored waste cooking oil and yeast extract, achieving a PHA production titer of 1.13 g/L, while Metabacillus niabensis preferred waste olive oil and urea, with a PHA production titer of 0.85 g/L. Both strains exhibited optimal growth at a neutral pH of 7, under optimal shaking -flask conditions. The bioreactor performance showed improved PHA production under controlled pH conditions, with a final titer of 9.75 g/L for Neobacillus niacini and 4.78 g/L for Metabacillus niabensis. Fourier transform infrared (FT-IR) spectroscopy and gas chromatography–mass spectrometry (GC-MS) confirmed the biosynthesized polymer as mcl-PHA. This research not only offers a sustainable method for transforming waste into valuable materials, but also provides insights into the optimal conditions for microbial PHA production, advancing environmental science and materials engineering.

Graphene oxide (GO) and reduced graphene oxide (rGO) nanoparticles were synthesized using 40 mL of lemon juice extract as a reducing agent. The synthesized nanoparticles were characterized using various analytical techniques, including UV–visible spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The results confirmed the successful synthesis of GO and rGO nanoparticles with varied sizes and shapes. The synthesized nanoparticles were tested for their antimicrobial activity against a range of bacterial and fungal strains, including Escherichia coli, Staphylococcus aureus , Klebsiella pneumoniae, Candida albicans, Fusarium oxysporum, and Aspergillus flavus . Multiple concentrations of GO and rGO nanoparticles were tested, and it was observed that 100 µg·mL ⁻¹ of both GO and rGO showed the highest inhibitory effect against bacterial and produced zones of inhibition of 17.66 mm, 18.67 mm, and 17.88 for E. coli, S. aureus , K. pneumoniae and 20.33, 22.45, and 21.34 mm for C. albicans, F. oxysporum, and A. flavus . Comparatively, GO performed well as compared to rGO regarding antimicrobial activity. The synthesized nanoparticles exhibited significant antimicrobial activity against various bacterial and fungal strains and have the potential to be developed as novel antimicrobial agents.

The green synthesis of multifunctional nanomaterials from agricultural waste is a major target in sustainable biomedicine. This study reports the eco-friendly, one-pot synthesis of copper-doped titanium dioxide nanoparticles (Cu–TiO ₂ NPs) using an aqueous peel extract of Citrus limon (Linn.) Burm. f. The formation of the nanoparticles was observed using the ultraviolet-visible spectroscopy, with an absorption edge below 400 nm with a redshift in the visible range (400–650 nm). X-ray diffraction (XRD) confirmed a mixed anatase-rutile crystalline phase, with an average crystallite size of 45.6 nm, and scanning electron microscopy (SEM) showed irregularly shaped agglomerated nanoparticles with an average diameter of 48 ± 0.46 nm. Field Emission Scanning Electron Microscopy (FESEM) revealed irregular, highly agglomerated nanoparticles with a primary size range of 49 ± 07 nm, while X-ray Photoelectron Spectroscopy (XPS) confirmed the oxidation states of Ti, O, and Cu, validating successful doping. Energy-Dispersive X-ray (EDX) analysis further confirmed uniform Cu incorporation into the TiO₂ lattice. In vitro testing showed a dose-dependent antibacterial effect against Staphylococcus aureus (ATCC 9144), Staphylococcus epidermidis (ATCC 12228), and Pseudomonas aeruginosa (ATCC 10145), with minimum inhibitory concentration (MIC) values ranging from 15 to 20 µg/mL. The highest zone of inhibition for Cu-TiO₂NPs was 21.00 ± 0.29 mm against S. epidermidis at 30 µg/mL, similar to the effect observed with ceftriaxone (30 µg/mL). The nanoparticles exhibited high antioxidant capacity, with a ferric reducing antioxidant potential of 67.5 ascorbic acid equivalents (AAE) µg/mL and a 54% 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity at 500 µg/mL. Cytotoxicity was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, which indicated dose-dependent cytotoxicity in human hepatocellular carcinoma (HepG2) cells, with an IC ₅₀ of 150 µg/mL after 24 h. The stabilization of the L-ascorbic acid-Cu–TiO₂NPs complex was investigated using Density Functional Theory (DFT), and molecular docking revealed strong interactions with the target bacteria. This study uniquely integrates sustainable waste valorization, comprehensive in vitro bio evaluation, and computational validation of lemon peel-derived Cu-TiO ₂ NPs for biomedical applications.

Colorectal cancer is one of the leading causes of cancer-associated mortality across the worldwide. One of the major challenges in colorectal cancer is the understanding of the regulatory mechanisms of biological molecules. In this study, we aimed to identify novel key molecules in colorectal cancer by using a computational systems biology approach. We constructed the colorectal protein–protein interaction network which followed hierarchical scale-free nature. We identified TP53, CTNBB1, AKT1, EGFR, HRAS, JUN, RHOA, and EGF as bottleneck-hubs. The HRAS showed the largest interacting strength with functional subnetworks, having strong correlation with protein phosphorylation, kinase activity, signal transduction, and apoptotic processes. Furthermore, we constructed the bottleneck-hubs’ regulatory networks with their transcriptional (transcription factor) and post-transcriptional (miRNAs) regulators, which exhibited the important key regulators. We observed miR-429, miR-622, and miR-133b and transcription factors (EZH2, HDAC1, HDAC4, AR, NFKB1, and KLF4) regulates four bottleneck-hubs (TP53, JUN, AKT1 and EGFR) at the motif level. In future, biochemical investigation of the observed key regulators could provide further understanding about their role in the pathophysiology of colorectal cancer.