Lignocellulose, the main component of a plant cell wall, is a potential renewable bioenergy source. It is composed of cellulose, hemicellulose, and lignin structures. Cellulose is a linear polysaccharide that is hydrolyzed chemically or enzymatically by cellulase. The addition of lignocellulosic biomass, such as wheat bran and coffee pulp, into the fermentation culture, induces the production of cellulases. Cellulose accounts for 20% of the enzyme market worldwide, demonstrating benefits in diverse applications, especially bioethanol and biogas generation. The aim is to evaluate the optimal condition for bioethanol production by previously isolated fungal species from different soil types in the eastern region of the Kingdom of Saudi Arabia. This study attempts to evaluate and optimize the culture conditions of lignocellulosic biomass under SSF using the highest cellulases-producer strains in the region: Aspergillus niger and Aspergillus flavus (GenBank Accession No. MT328516 and MT328429, respectively) to produce raw sugar that consequently is used in the next step of bioethanol production. This process has two parts: (1) hydrolyze lignocellulosic biomass to obtain raw sugar using A. niger and A. flavus that produce cellulase, and (2) produce bioethanol through the conversion of the raw sugar produced from the cellulolysis into ethanol using Saccharomyces cerevisiae. The optimal conditions under SSF were seven days of incubation, 5% glucose as a carbon source, 1% ammonium sulfate as a nitrogen source, and 80% moisture for both isolates. Biochemical characterization showed stability for the immobilized enzyme in all temperature ranges (from 20 °C to 70 °C), while the free enzyme exhibited its maximum at 20 °C of 1.14 IU/mL. CMCase production was the highest at pH 4.0 (1.26 IU/mL) for free enzyme and at pH 5.0 (2.09 IU/mL) for the immobilized form. The CMCase activity increased steadily with an increase in water level and attained a maximum of 80% moisture content. The maximum enzyme activity was with coffee pulp as a substrate of 7.37 IU/mL and 6.38 IU/mL for A. niger and A. flavus after seven days of incubation, respectively. The Carboxymethyl Cellulase (CMCase) activity in immobilized enzymes showed good storage stability under SSF for six weeks, maintaining 90% of its initial activity, while the free enzyme retained only 59% of its original activity. As a carbon source, glucose was the best inducer of CMCase activity with coffee pulp substrate (7.41 IU/mL and 6.33 IU/mL for A. niger and A. flavus, respectively). In both fungal strains, ammonium sulfate caused maximum CMCase activities with coffee pulp as substrate (7.62 IU/mL and 6.47 IU/mL for A. niger and A. flavus, respectively). Immobilized S. cerevisiae showed an increase in ethanol production compared to free cells. In the case of immobilized S. cerevisiae cells, the concentration of ethanol was increased steadily with increasing fermentation time and attained a maximum of 71.39 mg/mL (A. niger) and 11.73 mg/mL (A. flavus) after 72 h of fermentation.

Due to the indiscriminate use of antimicrobial drugs in the treatment of infectious diseases, human pathogenic bacteria have developed resistance to many commercially available antibiotics. Medicinal plants such as Convolvulus arvensis represent a renewable resource for the development of alternative therapeutic agents. This study aimed to evaluate the antibacterial activity of silver nanoparticles (AgNPs) biosynthesized from C. arvensis against two clinical antibiotic-resistant bacterial isolates. The pathogenic isolates were identified as Staphylococcus aureus MRSA and Escherichia coli ESBL using 16S rRNA gene sequencing. Silver nanoparticles were synthesized via a green synthesis approach, and their physicochemical properties were characterized using UV–Vis spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, zeta potential, and dynamic light scattering (DLS). The synthesized C. arvensis–AgNPs exhibited a surface plasmon resonance peak at 475 nm and predominantly spherical morphology with particle sizes ranging from 102.34 to 210.82 nm. FTIR analysis indicated the presence of O–H, C–O, C–N, C–H, and amide functional groups. The nanoparticles showed a zeta potential of −18.9 mV and an average hydrodynamic diameter of 63 nm. The antibacterial activity of the biosynthesized AgNPs was evaluated against methicillin-resistant S. aureus (MRSA and ATCC 29213) and E. coli (ESBL and ATCC 25922) using agar diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Inhibition zones ranged from 10 to 13 mm, with MIC and MBC values of 12.5–25 µg/mL and 25–50 µg/mL, respectively. In addition, the nanoparticles exhibited antioxidant activity (DPPH assay, IC₅₀ = 0.71 mg/mL) and anti-inflammatory effects as determined by protein denaturation inhibition. No cytotoxic effects were observed in the MCF-7 cell line at the MIC level. These findings suggest that C. arvensis–AgNPs have potential as natural antimicrobial, antioxidant, and anti-inflammatory agents.

Autism is a complex disease with genetic predisposition factors. Real factors for treatment and early diagnosis are yet to be defined. This study integrated transcriptome and exome genotyping for identifying functional variants associated with autism spectrum disorder and their impact on gene expression to find significant variations. More than 1800 patients were screened, and 70 (47 male/23 female) with an average age of 7.56 ± 3.68 years fulfilled the DSM-5 criteria for autism. Analysis revealed 682 SNPs of 589 genes significantly (p < 0.001) associated with autism among the putative functional exonic variants (n = 243,345) studied. Olfactory receptor genes on chromosome 6 were significant after Bonferroni correction (α = 0.05/243345 = 2.05 × 10⁻⁷) with a high degree of linkage disequilibrium on 6p22.1 (p = 6.71 × 10⁻⁹). The differentially expressed gene analysis of autistic patients compared to controls in whole RNA sequencing identified significantly upregulated (foldchange ≥0.8 and p-value ≤ 0.05; n = 125) and downregulated (foldchange ≤−0.8 and p-value ≤ 0.05; n = 117) genes. The integration of significantly up- and downregulated genes and genes of significant SNPs identified regulatory variants (rs6657480, rs3130780, and rs1940475) associated with the up- (ITGB3BP) and downregulation (DDR1 and MMP8) of genes in autism spectrum disorder in people of Arab ancestries. The significant variants could be a biomarker of interest for identifying early autism among Arabs and helping to characterize the genes involved in the susceptibility mechanisms for autistic subjects.

Objective. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main causative agents of nosocomial infections that has posed a major threat to those with compromised immune systems such as nursing home residents. The aim of this study was to determine the rates of MRSA strains and the types of Staphylococcal Cassette Chromosome mec (SCCmec)in nursing homes in Saudi Arabia. Methods. A total of 188 nasal swabs were collected from the residents and nursing staff in two nursing homes in Riyadh, Saudi Arabia. All MRSA isolates were tested for antimicrobial susceptibility and analyzed for mecA and SCCmec typing by multiplex PCR assay. Detection of the Panton–Valentine leukocidin (PVL) gene was also tested in all positive MRSA isolates by multiplex PCR using specific primers. Results. Among the 188 collected nasal swabs (105 males and 83 females), MRSA colonization rate was 9.04% (11 (5.85%) females and 6 (5.71%) males). About 47% of MRSA were multidrug resistant (MDR) as acquired resistance to beta-lactam, macrolide, and aminoglycoside antibiotics. However, all the MRSA isolates showed susceptibility to vancomycin, tigecycline, and linezolid. All the MRSA isolates (n = 17) were mecA-positive with the SCCmec IVc (n = 7, 41.18%) as the most common SCCmec type followed by SCCmec V (n = 5, 29.41%) and SCCmec IVa (n = 2, 11.76%). The remaining isolates (n = 3) were nontypeable (17.65%). In addition, the PVL toxin gene was only detected in four of the male samples. Conclusion. MRSA nasal colonization is a common incident among nursing home residents. The prevalence of community-associated (CA) MRSA (SCCmec IV and V) was more common than hospital-associated (HA) MRSA in our study samples. It is crucial to investigate such rate of incidence, which is a key tool in preventive medicine and would aid in determining health policy and predict emergent outbreaks.

The two-spotted spider mite (TSSM) Tetranychus urticae, is regarded as one of the most dangerous pests responsible for great losses in most of agricultural crops. It is a persistent pest in Saudi Arabia, especially in greenhouses where T. urticae is primarily controlled by chemical pesticides. The main problem for the two-spotted spider mites is its high resistance to pesticides and high fertility rate. In the long term, chemical pesticides cause health problems and economic losses, so it was necessary to search for a safe alternative method for human health and the environment. One of these alternative methods was the selection of plant varieties resistant to the TSSM, in addition to biological control that includes mites or predatory insects and entomopathogenic fungi. The growth, reproduction, and life-table parameters of T. urticae were examined in a laboratory setting with a 16L:8D photoperiod at 28±1°C and 65±5% RH, in the presence of three major members of Family: Solanaceae tomato, eggplant, and pepper. Pepper was shown to be less conducive to T. urticae growth and reproduction compared to eggplant and tomato. Tetranychus urticae proceeded through all five stages of its life cycle (egg, larva, protonymph, deutonymph, and adult) on tested solanaceous plants, and these plants significantly influenced its growth, reproduction, and Life-table parameters. Additionally, entomopathogenic fungi have been used against insects that have proven highly effective in controlling and reducing the density of two-spotted spider mites. Eight fungi were isolated from 80 insect and mite samples collected from several Saudi Arabia regions. Analysis of the 18S rRNA sequences revealed that the fungal strains identified as Beauveria bassiana, Fusarium sp. F. equiseti, F. oxysporium, Scopulariopsis brevicaulis1, S. brevicaulis2, Aspergillus sclerotiorum , and Penicillium citrinum. The ability of isolated fungi to secrete enzymes degrading the two-spotted spider mite cuticle, namely lipase, protease, and chitinase, were studied.

Laccase production was evaluated in 108 fungal isolates recovered from the eastern coast of Saudi Arabia, a critical element in environmental biodegradation and biotransformation. The most active isolate was identified as Curvularia lunata MLK46 (GenBank accession no. PQ100161). It exhibited maximal productivity at pH 6.5, 30 °C, and incubation for 5 d, with 1% sodium nitrate and 1% galactose as the preferred nitrogen and carbon sources, respectively. Productivity was enhanced by NaCl, CuSO₄, and FeCl₃ supplementation, with a maximum at 0.3 mM, 0.2 mM, and 61.7 mM concentrations, respectively. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) for the purified enzyme through diethylaminoethyl (DEAE)-Sepharose chromatography revealed a prominent band at 71.1 kDa with maximum activity at pH 6 and stability at pH 6–9. Furthermore, it was optimally active at 50 °C and thermally stable at 50–80 °C with a half-life time (T_1/2) of 333.7 min to 80.6 min, respectively. Its activity was also enhanced by many metallic ions, especially Fe³⁺ ions; however, it was inhibited by Hg²⁺ and Ag⁺ ions. The enzyme demonstrated significant degradation of specific substrates such as 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), guaiacol, o-dianisidine, and 2,6-dichlorophenol, with a kinetic efficiency constant which ranged from 40.95 mM⁻¹ s⁻¹ to 238.20 mM⁻¹ s⁻¹. UV spectrophotometry confirmed efficient oxidation peaks by electron transition against guaiacol (at 300 nm), o-dianisidine (at 480 nm), ABTS (at 420 nm), and 2,6-dichlorophenol (at 600 nm). The results collectively demonstrate the potential of laccase from C. lunata MLK46 as a promising agent for the effective biodegradation of several industrial pollutants under extreme conditions.