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This study aims to synthesize silver nanoparticles by the green method and test it against specific virulence factors in multi-drug resistant Enterococcus faecalis bacteria. virulence factors of E. faecalis clinical isolates were determined and the most potent isolate was selected for further investigations. The prepared Ag-NPs were characterized using UV spectroscopy, FTIR spectroscopy, dynamic light scattering, and transmission electron microscopy (TEM). The result revealed the concentration of 0.0625 mg/ml Ag-NPs was significantly reducing virulence factors in multidrug-resistant E. faecalis without affecting planktonic cell growth. UV-Visible spectroscopy characterization revealed a characteristic surface Plasmon band [SPR] at a wavelength ranging from 256 to 345 and 510 nm in the prepared Ag-NPs. dynamic light scattering indicated it tended to an electrostatic attraction between nanoparticles in the prepared solution. TEM images revealed the average size of Ag-NPs were prepared to be 28.8 nm and the shape was spherical. Green synthesized Ag-NPs have the ability to combat multi-drug-resistant E. faecalis via reducing virulence factors, which is considered a good approach toward resolving the multidrug resistance crisis.

Historic cultural heritage and archival manuscripts have a significant importance worldwide and efforts should be considered to preserve such property for as long as possible. The current study aimed to establish a non-toxic, and eco-friendly conservation strategy for retarding paper biodeterioration. To this end, fungal isolates associated with the biodeteriorated paper manuscripts of the historical book “DESCRIPTION DE L´EGYPTE” dating back to 1823 A.D were isolated. These isolates were identified as Asperigllus niger, Aspergillus flavus, Penicillium chrysogenum and Alternaria alternata and then evaluated for cellulolytic activities. Amongst them, Aspergillus niger A2 exhibited the highest cellulase activity. In in vitro study using filter papers as model, the suppressive effect of biosynthesized silver and zinc oxide nanoparticles (NPs) on A. niger A2 bioderteriorant activity was evaluated. Biosynthesized Ag-NPs and ZnO-NPs were characterized by UV-Vis spectroscopy, X-ray diffraction patterns (XRD), Transmission Electron Microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FT-IR). Color changes, tensile strength, FT-IR-spectroscopy, and scanning electron microscopy of NPs-treated papers were examined. Treatments with 2 mM Ag-NPs and 2 mM ZnO-NPs exhibited the best conservation effect on treated papers and alleviated cellulose degradation. Furthermore, this treatments enhanced tensile strength and preserved the original morphology of paper fibers. These results introduced a potential approach for historical documents conservation against fungal biodeterioration through NPs sprays. It can be also used for preparing anti-biodeterioration paper for expected manuscripts uses.

Effective lactic acid (LA) production from lignocellulosic biomass materials is challenged by several limitations related to pentose sugar utilization, inhibitory compounds, and/or fermentation conditions. In this study, a newly isolated Bacillus coagulans strain Azu-10 was obtained and showed homofermentative LA production from xylose with optimal fermentation conditions at 50 °C and pH 7.0. Growth of strain Azu-10 and LA-fermentation efficiency were evaluated in the presence of various lignocellulose-derived inhibitors (furans, carboxylic acids, and phenols) at different concentrations. Furanic lignocellulosic-derived inhibitors were completely detoxified. The strain has exhibited high biomass, complete xylose consumption, and high LA production in the presence of 1.0‒4.0 g/L furfural and 1.0‒5.0 g/L of hydroxymethyl furfural, separately. Moreover, strain Azu-10 exhibited high LA production in the presence of 5.0–15.0 g/L acetic acid, 5.0 g/L of formic acid, and up to 7.0 g/L of levulinic acid, separately. Besides, for phenolic compounds, p-coumaric acid was most toxic at 1.0 g/L, while syringaldehyde or p-hydroxybenzaldehyde, and vanillin at 1.0 g/L did not inhibit LA fermentation. The present study provides an interesting potential candidate for the thermophilic LA fermentation from lignocellulose-derived substrates at the industrial biorefinery level.

In this study, two endophytic actinomycetes isolates Oc-5 and Acv-11, were isolated from healthy leaves of medicinal plant Oxalis corniculata L. These isolates were identified as Streptomyces zaomyceticus Oc-5 and Streptomyces pseudogriseolus Acv-11 using 16S rRNA gene sequence. Biomass extract of these strains were used as a greener attempt for synthesis of copper oxide nanoparticles (CuO-NPs). The synthesized NPs were characterized by UV–Vis spectroscopy, Fourier transform infra-red (FT-IR) spectroscopy, X-ray diffraction (XRD)‚ transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS). Green synthesized NPs showed surface plasmon resonance (SPR) absorption band at 400 nm, crystalline nature, spherical-shaped with an average size of 78 nm and 80.0 nm for CuO-NPs synthesized using strain Oc-5 and Acv-11, respectively. The bioactivities of CuO-NPs were evaluated. Results revealed that CuO-NPs exhibited promising antimicrobial activity against prokaryotic and eukaryotic microbial cells (Gram positive bacteria, Gram negative bacteria, unicellular and multicellular fungi). In addition, it showed antimicrobial potential against phyto-pathogenic fungal strains Fusarium oxysporum, Pythium ultimum, Aspergillus niger and Alternaria alternata. We further explored the in vitro antioxidant activity and cytotoxicity for biosynthesized CuO-NPs. The results revealed that‚ scavenging and total antioxidant activity for NPs synthesized using Streptomyces pseudogriseolus Acv-11 was better than those synthesized by Streptomyces zaomyceticus Oc-5. Also, the morphological changes and cell viability for Vero and Caco-2 cell line due to NPs treatments were assessed using MTT assay method. Furthermore, Larvicidal efficacy against Musca domestica and Culex pipiens was evaluated. The results obtained in this study clearly showed that biosynthesized CuO-NPs exhibited effective bioactivity and, therefore, provide a base for the development of versatile biotechnological applications soon.

In this study, 15 bacterial endophytes linked with the leaves of the native medicinal plant Pulicaria incisa were isolated and identified as Agrobacterium fabrum, Acinetobacter radioresistant, Brevibacillus brevis, Bacillus cereus, Bacillus subtilis, Paenibacillus barengoltzii, and Burkholderia cepacia. These isolates exhibited variant tolerances to salt stress and showed high efficacy in indole-3-acetic acid (IAA) production in the absence/presence of tryptophan. The maximum productivity of IAA was recorded for B. cereus BI-8 and B. subtilis BI-10 with values of 117 &plusmn, 6 and 108 &plusmn, 4.6 &mu, g mL&minus, 1, respectively, in the presence of 5 mg mL&minus, 1 tryptophan after 10 days. These two isolates had a high potential in phosphate solubilization and ammonia production, and they showed enzymatic activities for amylase, protease, xylanase, cellulase, chitinase, and catalase. In vitro antagonistic investigation showed their high efficacy against the three phytopathogens Fusarium oxysporum, Alternaria alternata, and Pythium ultimum, with inhibition percentages ranging from 20% &plusmn, 0.2% to 52.6% &plusmn, 0.2% (p &le, 0.05). Therefore, these two endophytic bacteria were used as bio-inoculants for maize seeds, and the results showed that bacterial inoculations significantly increased the root length as well as the fresh and dry weights of the roots compared to the control plants. The Zea mays plant inoculated with the two endophytic strains BI-8 and BI-10 significantly improved (p &le, 0.05) the growth performance as well as the nutrient uptake compared with an un-inoculated plant.