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Textile industry effluents contain several hazardous substances, such as dye-containing effluents, which pose environmental and aesthetic challenges. Presently, the microbial-based remediation process is in use. This study investigated the application of ferrous–ferric oxide (Fe3O4) nanoparticles, a readily formulated nanoadsorbent, to remove scattered dye molecules from industrial effluents. The ferrous–ferric oxide nanoparticles were prepared using a chemical co-precipitation method. The nanoparticles had 26.93 emu g−1 magnetization, with sizes smaller than 20 nm, and possessed a highly purified cubic spinel crystallite structure. The catalytic activity of the iron oxide depended on the dose, photocatalytic enhancer, i.e., H2O2 level, pH of the reaction medium, and dye concentration. We optimized the Fenton-like reaction to work best using 1.0 g/L of ferrous–ferric oxide nanoparticles, 60 mM oxalic acid at pH 7.0, and 60 ppm of dye. Iron oxides act as photocatalysts, and oxalic acid generates electron–hole pairs. Consequently, higher amounts of super-radicals cause the rapid degradation of dye and pseudo-first-order reactions. Liquid chromatography–mass spectrometry (LC-MS) analysis revealed the ferrous–ferric oxide nanoparticles decolorized and destroyed Disperse Red 277 in 180 min under visible light. Hence, complete demineralization is observed using a photo-Fenton-like reaction within 3 h under visible light. These high-capacity, easy-to-separate next-generation adsorption systems are suggested to be suitable for industrial-scale use. Ferrous–ferric oxide nanoparticles with increased adsorption and magnetic properties could be utilized to clean environmental pollution. [ABSTRACT FROM AUTHOR]

Amentotaxus yunnanensis H.L.Li is a threatened conifer distributed only in China, Laos, and Vietnam, whose fungal endophytes have not been exploited yet. The aims of this study were to screen and characterize antioxidant metabolites from endophytic fungi obtained from A. yunnanensis. Using the surface sterilization method, sixteen endophytic fungi were isolated from A. yunnanensis and classified into seven genera including Fusarium, Penicillium, Aspergillus, Diaporthe, Neopestalotiopsis, Purpureocillium, and Simplicillium through the analysis of Internal Transcribed Spacer (ITS) gene sequences. Among the ethyl acetate crude extracts, Fusarium foetens AQF6 contained the highest amount of polyphenol (117.76 ± 0.94 mg gallic acid equivalent/g) and flavonoid (169.01 ± 2.09 mg quercetin equivalent/g). Importantly, 400 µg/mL AQF6 extract exhibited 95.75 ± 1.1% and 85.66 ± 1.91% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical-scavenging activities, respectively. Chemical investigation led to the isolation and identification of a new bisabolane-type sesquiterpene fusafoetriol (FUS) and 14 known compounds, among which six pure compounds showed free-radical scavenging activity against DPPH and hydroxyl radicals. Under H2O2 stress, the yeast model Saccharomyces cerevisiae treated with 4 mM FUS showed 43.31% increase in viability. FUS has the potential to be applied in nutraceutical, pharmaceutical and food technological applications. Thus, this is the first report demonstrating the presence of endophytic fungi inhabiting A. yunnanensis and their potential as a prolific source of antioxidant metabolites. [ABSTRACT FROM AUTHOR]

Exopolysaccharides (EPSs) produced by Bacillus species have recently emerged as promising commercial antioxidants in various industries, such as pharmaceutics and biomedicine. However, little is known about EPS production and function from Bacillus velezensis so far. In the present study, the effect of sugar sources on EPS production by B. velezensis VTX20 and the genetic biosynthesis, characteristics, and antioxidant activity of the resulting EPS were evaluated. The strain VTX20 produced the maximum EPS yield of 75.5 ± 4.8 g/L from an initial 200 g/L of sucrose after a 48-h cultivation. Through genomic analysis, ls-levB operon was found, for the first time, to be responsible for the levan-type EPS production in B. velezensis. Biochemical and structural characterization further confirmed the majority of levan, followed by an extremely low level of dextran biopolymer. The water solubility index and water holding capacity of the EPSs were 81.9 ± 3.4% and 100.2 ± 3.4%, respectively. In vitro antioxidant activity analyses showed strong scavenging activity for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical values of 40.1–64.0% and 16.0–40%, respectively. These findings shed light on the EPS biosynthesis of B. velezensis at both structural and genetic levels and the potential application of EPS as a natural antioxidant for pharmaceutical and biomedical industries. [ABSTRACT FROM AUTHOR]

Fungi are the most harmful microorganisms responsible for the deterioration of nonmetallic materials such as glass, polymers, and composites. To date, biological aspects of glass deterioration have been poorly investigated. The present study aimed to evaluate the diversity of the fungal community colonizing eyepieces of binoculars collected from museums of the northern provinces of Vietnam and the biodeterioration effects on accurate glass reproductions. A total of 40 isolates belonging to 14 genera were identified based on internal transcribed spacer (ITS) sequencing, morphological features, and maximum likelihood analysis. The most abundant fungal genera included Aspergillus (43.8%) and Penicillium (31.3%). Among those detected, Byssochlamys, Curvularia, Phomopsis, Coprinellus, Perenniporia, Talaromyces, Pithomyces, Neopestalotiopsis, Trichoderma, Pleospora, and Humicola were found for the first time. Of the 40 strains tested, 8 strains showed great organic acid production, and the extent of mycelium covered from 33.6 to 46.24%. Specifically, the highest extracellular polymeric substance production was observed in Byssochlamys spectabilis BXMA1-2 (14.96 g/L), Aspergillus niger BXMA5-2 (12.17 g/L), and Aspergillus ochraceopetaliformis BMLC1-2 (9.89 g/L). Glass biodeterioration experiments revealed that the light transmission through the fungal-treated glasses was decreased by 30–42.2% as compared to the nontreated glass. In addition, the main alterations resulted from hyphal fingerprints and spots, leading to apparent damage and biocorrosion. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the synergistic effects of the crude ethyl acetate extract (CEAE) from endophytic actinomycete MPT42 and essential oil (EO) of the same host plant Litsea cubeba. The isolate MPT42, exhibiting broad-spectrum antimicrobial activities and harboring all three antibiotic-related biosynthetic genes pks-I, pks-II, and nrps, was identified as Streptomycete griseorubens based on an analysis of the morphology, physiology, and 16S rDNA sequence. Minimum inhibitory concentrations (MICs) and the fractional inhibitory concentration index were used to estimate the synergistic effects of various combined ratios between CEAE or antibiotics (erythromycin, vancomycin) and EO toward 13 microbial strains including pathogens. L. cubeba fruit EO, showing the main chemical constituents of 36.0% citral, 29.6% carveol, and 20.5% limonene, revealed an active-low against tested microbes (MICs ≥ 600 μg/mL). The CEAE of S. griseorubens culture exhibited moderate–strong antimicrobial activities against microbes (MICs = 80–600 μg/mL). Analysis of the mechanism of action of EO on Escherichia coli ATCC 25922 found that bacterial cells were dead after 7 h of the EO treatment at 1 MIC (5.5 mg/mL), where 62% cells were permeabilized after 2 h and 3% of them were filament (length ≥ 6 μm). Combinations of CEAE, erythromycin, or vancomycin with EO led to significant synergistic antimicrobial effects against microbes with 4–16 fold reduction in MIC values when compared to their single use. Interestingly, the vancomycin–EO combinations exhibited a strong synergistic effect against five Gram-negative bacterial species. This could assume that the synergy was possibly due to increasing the cell membrane permeability by the EO acting on the bacterial cells, which allows the uptake and diffusion of antimicrobial substances inside the cell easily. These findings in the present study therefore propose a possible alternative to combat the emergence of multidrug-resistant microbes in veterinary and clinics. [ABSTRACT FROM AUTHOR]