Impact of silver ions and silver nanoparticles on biochemical parameters and antioxidant enzyme modulations in Saccharomyces cerevisiae under co-exposure to static magnetic field: a comparative investigation.

The increase in simultaneous exposure to magnetic fields and other hazardous compounds released from industrial applications poses multiple stress conditions on the ecosystems and public human health. In this work, we investigated the effects of co-exposure to a static magnetic field (SMF) and silver ions (AgNO3) on biochemical parameters and antioxidant enzyme activities in the yeast Saccharomyces cerevisiae. Sub-chronic exposure to AgNO3 (0.5 mM) for 9 h resulted in a significant decrease in antioxidant enzyme activity, including glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and glutathione transferase (GST). The total glutathione (GSH) level increased in yeast cells exposed to Ag. Additionally, a notable elevation in malondialdehyde (MDA) levels and protein carbonyl content was observed in both the AgNP and AgNO3 groups compared to the control group. Interestingly, the SMF alleviated the oxidative stress induced by silver nitrate, normalizing antioxidant enzyme activities by reducing cellular ROS formation, MDA levels, and protein carbonylation (PCO) concentrations.

Isolation and characterization of a newly chrysene-degrading Achromobacter aegrifaciens.

Polycyclic aromatic hydrocarbons (PAHs) are considered substances of potential human health hazards because of their resistance to biodegradation and carcinogenic index. Chrysene is a PAH with a high molecular weight (HMW) that poses challenges for its elimination from the environment. However, bacterial degradation is an effective, environmentally friendly, and cost-effective solution. In our study, we isolated a potential chrysene-degrading bacteria from crude oil-contaminated seawater (Bizerte, Tunisia). Based on 16SrRNA analysis, the isolate S5 was identified as Achromobacter aegrifaciens. Furthermore, the results revealed that A. aegrifaciens S5 produced a biofilm on polystyrene at 20 °C and 30 °C, as well as at the air-liquid (A-L) interface. Moreover, this isolate was able to swim and produce biosurfactants with an emulsification activity (E24%) over 53%. Chrysene biodegradation by isolate S5 was clearly assessed by an increase in the total viable count. Confirmation was obtained via gas chromatography-mass spectrometry (GC-MS) analyses. A. aegrifaciens S5 could use chrysene as its sole carbon and energy source, exhibiting an 86% degradation of chrysene on day 7. In addition, the bacterial counts reached their highest level, over 25 × 1020 CFU/mL, under the conditions of pH 7.0, a temperature of 30 °C, and a rotary speed of 120 rpm. Based on our findings, A. aegrifaciens S5 can be a potential candidate for bioremediation in HMW-PAH-contaminated environments.

Musico-bioremediation of seafood canning wastewater by Yarrowia lipolytica.

Due to the lack of water resources and the harmful effects of wastewater on environment and human health, treatment of wastewater becomes necessary. The present study explored the effect of musical sounds on the biological treatment of seafood canning wastewater by using Yarrowia lipolytica. Our results showed that low frequency (21 Hz to 1356 Hz) and high frequency (21 Hz to 16,214 Hz) musical sounds stimulated the growth of Y. lipolytica and increased the polluant removal efficiency. Such treatment decreased significantly the chemical oxygen demand (COD) and salinity as well as the color of this wastewater. Our study revealed that low frequency musical sounds are more effective in COD (87.5%) and salinity (44%) reduction as well as the decolorization (86.46%) of this effluent. Additionally, after 7 days of incubation significant yeast cell dry biomass (3.46 ± 0.22 g/L) and single cell proteins (46.45 ± 0.7 mg/g) were obtained under low frequency waves. Musico-bioremediation represents an innovative ecotechnological approach to wastewater treatment with low operating costs and significant environmental benefits.

Therapeutic potential of second degree's skin burns by topical dressing of Teucrium ramosissimum that promotes re-epithelialization.

The aim of the report is to assess the protective effect of powder aerial part of Teucrium ramosissimum (TS) on the in vivo wound-healing of second-degree burn injuries. Teucrium phytocompounds were characterized by FTIR, HPLC, and GC/MS spectra. Burn wound models were employed to evaluate the in vivo wound-healing activity. Thirty six wistar rats with burn wounds were divided into six groups and treated daily with TS, the mixture of Teucrium and honey (TS-HY), thymol and Dermosalic® (0.05%) (DS) creams. Skin epithelialization was monitored on the 4th, 13th, and 21st days. Proteins and the level of malondialdehyde in the burned skin were assessed. Microscopic and macroscopic investigations of skin wound tissues showed significant wound closure rate via complete epidermal reepithelization and regeneration, higher protein content, collagen synthesis and deposition, hair follicles growth post wounding that were promoted in TS-, thymol-, TS-HY- and DS-treated wound tissues compared to the untreated burned wound tissues that was characterized by the absence of the epithelialization, vascularization and the formation of the epidermis layer. Additionally, the skin healing potential of TS and TS-HY was validated by markedly decreased of lipid peroxidation. Overall, TS was found to possess complete wound closure and improves the healing process.

Growth and biofilm formation of Cupriavidus metallidurans CH34 on different metallic and polymeric materials used in spaceflight applications.

Bacteria biofilm formation and its complications are of special concern in isolated structures, such as offshore stations, manned submarines and space habitats, as maintenance and technical support are poorly accessible due to costs and/or logistical challenges. In addition, considering that future exploration missions are planned to adventure farther and longer in space, unlocking biofilm formation mechanisms and developing new antifouling solutions are key goals in order to ensure spacecraft's efficiency, crew's safety and mission success. In this work, we explored the interactions between Cupriavidus metallidurans, a prevalently identified contaminant onboard the International Space Station, and aerospace grade materials such as the titanium alloy TiAl6V4, the stainless steel AISI 316 (SS316) and Polytetrafluoroethylene (PTFE) or Teflon. Borosilicate glass was used as a control and all surfaces were investigated at two different pH values (5.0 and 7.0). Biofilms were almost absent on stainless steel and the titanium alloy contrary to Teflon and glass that were covered by an extensive biofilm formed via monolayers of scattered matrix-free cells and complex multilayered clusters or communities. Filamentous extracellular DNA structures were observed specifically in the complex multilayered clusters adherent to Teflon, indicating that the employed attachment machinery might depend on the physicochemical characteristics of the surface.

Morphological and Mechanical Characterization of Extracellular Vesicles and Parent Human Synoviocytes under Physiological and Inflammatory Conditions.

The morphology of fibroblast-like synoviocytes (FLS) issued from the synovial fluid (SF) of patients suffering from osteoarthritis (OA), rheumatoid arthritis (RA), or from healthy subjects (H), as well as the ultrastructure and mechanical properties of the FLS-secreted extracellular vesicles (EV), were analyzed by confocal microscopy, transmission electron microscopy, atomic force microscopy, and tribological tests. EV released under healthy conditions were constituted of several lipid bilayers surrounding a viscous inner core. This "gel-in" vesicular structure ensured high mechanical resistance of single vesicles and good tribological properties of the lubricant. RA, and to a lesser extent OA, synovial vesicles had altered morphology, corresponding to a "gel-out" situation with vesicles surrounded by a viscous gel, poor mechanical resistance, and poor lubricating qualities. When subjected to inflammatory conditions, healthy cells developed phenotypes similar to that of RA samples, which reinforces the importance of inflammatory processes in the loss of lubricating properties of SF.

Synovial Extracellular Vesicles: Structure and Role in Synovial Fluid Tribological Performances.

The quality of the lubricant between cartilaginous joint surfaces impacts the joint's mechanistic properties. In this study, we define the biochemical, ultrastructural, and tribological signatures of synovial fluids (SF) from patients with degenerative (osteoarthritis-OA) or inflammatory (rheumatoid arthritis-RA) joint pathologies in comparison with SF from healthy subjects. Phospholipid (PL) concentration in SF increased in pathological contexts, but the proportion PL relative to the overall lipids decreased. Subtle changes in PL chain composition were attributed to the inflammatory state. Transmission electron microscopy showed the occurrence of large multilamellar synovial extracellular vesicles (EV) filled with glycoprotein gel in healthy subjects. Synovial extracellular vesicle structure was altered in SF from OA and RA patients. RA samples systematically showed lower viscosity than healthy samples under a hydrodynamic lubricating regimen whereas OA samples showed higher viscosity. In turn, under a boundary regimen, cartilage surfaces in both pathological situations showed high wear and friction coefficients. Thus, we found a difference in the biochemical, tribological, and ultrastructural properties of synovial fluid in healthy people and patients with osteoarthritis and arthritis of the joints, and that large, multilamellar vesicles are essential for good boundary lubrication by ensuring a ball-bearing effect and limiting the destruction of lipid layers at the cartilage surface.

relA and spoT Gene Expression is Modulated in Salmonella Grown Under Static Magnetic Field.

Virtually all bacterial species synthesize high levels of (p)ppGpp (guanosine penta- or tetraphosphate), a pleiotropic regulator of the stringent response and other stresses in bacteria. relA and spoT genes are, respectively, involved in synthesis and synthesis/biodegradation of (p)ppGpp. We aimed in this work to evaluate the impact of static magnetic field (SMF) 200 mT exposure on the expression of relA and spoT genes in Salmonella enterica Hadar. Bacteria were exposed to a SMF during 9 h, and RNA extraction was followed by reverse transcriptase polymerase chain reaction (RT-PCR). The relative quantification of mRNA expression levels using the 16S rRNA reference gene did not change during the SMF exposure. However, results showed a significant increase in gene expression for relA after 3 h of exposure (P < 0.05) and after 6 h for spoT (P < 0.05). The differential gene expression of relA and spoT could be considered as a potential stress response to a SMF exposure in Salmonella related to the production/degradation of (p)ppGpp.

Size Fractionation of Titania Nanoparticles in Wild Dittrichia viscosa Grown in a Native Environment.

We report a size fractionation of titania (TiO2) nanoparticles absorbed from the environment and found within wild Dittrichia viscosa plants. The nanoparticles were isolated by extraction and isolation from distinct plant organs, as well as from the corresponding rhizosphere of wild, adult plants. The collected nanoparticles were characterized by scanning transmission electron microscopy coupled with energy dispersive X-ray spectroscopy (STEM-EDS). More than 1200 TiO2 nanoparticles were analyzed by these techniques. The results indicated the presence of TiO2 nanoparticles with a wide range of sizes within the inspected plant organs and rhizospheres. Interestingly, a size selective process occurs during the internalization and translocation of these nanoparticles (e.g., foliar and root uptake), which favors the accumulation of mainly TiO2 nanoparticles with diameters <50 nm in the leaves, stems, and roots. In fact, our findings indicate that among the total number of TiO2 nanoparticles analyzed, the fraction of the particles with dimensions <50 nm were 52% of those within the rhizospheres, 88.5% of those within the roots, 90% of those within the stems, and 53% of those within the leaves. This significant difference observed in the size distribution of the TiO2 nanoparticles among the rhizosphere and the plant organs could have impacts on the food chain and further biologicals effects that are dependent on the size of the TiO2.

Dual Valorization of Olive Mill Wastewater by Bio-Nanosynthesis of Magnesium Oxide and Yarrowia lipolytica Biomass Production.

This research investigates an efficient dual valorization of olive mill wastewater in the biosynthesis of magnesium oxide nanoparticles and in the depollution of the effluent by Yarrowia lipolytica growth evaluation. After removal of polyphenols, the recovered biophenols were reacted with the magnesium precursor to provide magnesium oxide nanoparticles. In order to confirm the biosynthesized magnesium oxide nanoparticles, several analyses were undertaken. The Fourier transform infrared spectrum gives a broad absorption at 658 cm-1 confirming the presence of the magnesium oxide nanoparticles, while the UV/VIS absorption spectroscopy reveals an intense transition with a maximum absorption at 300 nm. The X-ray diffraction and transmission electron microscopy analyses show that nanoparticles are in pure cubic crystalline with spherical and hexagonal shapes (average size is 19.4 nm). The zeta potential analysis illustrates a negative potential proving a good stability of the biosynthesized nanoparticles. Nanoparticles were assigned for their in vitro antibacterial activity against Escherichia coli, Enterobacter aerogenes, Salmonella typhimurium, Staphylococcus cohnii, and Bacillus niacini. The evaluation of the growth of Yarrowia lipolytica on the recovered olive mill wastewater after removal of polyphenols yielded 3.2 g/L of the Yarrowia biomass in 72 h without nutriment additions, providing an important decrease of chemical oxygen demand (73 %).

Histopathological and Biochemical Effects of Thyme Essential Oil on H2O2 Stress in Heart Tissues.

BACKGROUND: Thymus algeriensis (T. algeriensis) is traditionally used in Tunisia to treat many human diseases. The aim of the present study was to investigate whether terpenes extracted from the aerial parts of T. algeriensis are potent cardioprotective agents for hydrogen peroxide (H2O2)-induced cardiotoxicity in rats. METHOD: Thirty (30) rats were divided into six groups as per the experimental design: control (n = 6); 0.1 mmol/L H2O2 (LD H2O2) (n = 6); 1 mmol/L H2O2 (HD H2O2) (n = 6); oily fraction of T. algeriensis (OFTS) (180 mg/kg b.wt) (n = 6); OFTS + 0.1 mmol/L H2O2 (n = 6); and OFTS + 1 mmol/L H2O2 (n = 6). RESULTS: The H2O2 demonstrated concentration-dependent cardiotoxic effects in vitro. While, exposure of rats to OFTS significantly depleted H2O2-induced protein oxidation and lipid peroxidation, it raised antioxidant defence enzymes, and protected against H2O2-induced histopathological alterations. The antioxidant potential of the thyme essence was assessed by both enzymatic and non-enzymatic antioxidants. CONCLUSION: In conclusion, OFTS may be a potential compound for the therapy of oxidative stress-induced heart disease.

Antioxidant Potential of Four Species of Natural Product and Therapeutic Strategies for Cancer through Suppression of Viability in the Human Multiple Myeloma Cell Line U266.

OBJECTIVE: This research aimed to evaluate the protective effects of bioactive compounds such as phenolic acids, flavonoids, and tannins present in four species extracted with methanol. METHODS: The total phenolic content of the methanolic extracts was measured spectrophotometrically. The effect of the extracts on cell viability in U266 cells was measured. The effects of extracts on free radical scavenging were assessed by the DPPH test and FRAP assay. Antibacterial effects of the natural products in this report were investigated by using the disc diffusion method. RESULTS: Our results clearly demonstrated that the methanolic extracts were characterized by a high amount of phenolic compounds. It has been speculated that ME-TA and ME-TAl exhibit a significant (P < 0.05) and dose-dependent antiradical potential. The exposure of cells to high doses of extracts almost completely suppressed cell growth in vitro. ME-TA and ME-TAl showed significant cytotoxic effects at a concentration of 100 µg/mL in the U266 cell line. ME-TAl and ME-CF inhibited the growth of B. subtilis and S. aureus, respectively, to the same extent as 10 µg/µL of chloramphenicol at a concentration of 1 mg/mL. CONCLUSION: Overall, these results suggest that plants used in traditional medicine have a novel application as free radical scavengers, bacterial inhibitors and tumor suppressors.

Identification and sequence analysis of putative Sulla species nod factor receptor.

In legumes, LysM domains of receptors-like kinases (RLKs) mediate rhizobial NFs perception; which are required for infection and establishment of symbiosis without triggering the host immune response. In this study, we identify the LysM extracellular domain sequences of putative Sulla species Nod factor receptors (S. pallida, S. capitata and S. coronaria). The Blast search displayed high identity percentages with genes encoding LjNFR5-like of several legumes. Phylogenetic trees were built using the partial nod factor receptor and predicted amino acid sequences, which grouped Sulla in a separate clade. The multiple alignments of the LysM2 domains revealed that amino acids found to be important in other legume species are not conserved in Sulla species. Further examination of the predicted proteins sequences (LysM2 domain) showed that the three species were different in the two crucial sites for Nod factor perception.

Combined intervention of static magnetic field and growth rate of Microbacterium maritypicum CB7 for Benzo(a)Pyrene biodegradation.

In this work, we have shown for the first time that Microbacterium maritypicum CB7 bacterium is capable to use Benzo(a)Pyrene as a sole source of carbon and energy. We followed the growth kinetics of M. maritypicum CB7 in minimum medium supplemented with 10 mg/l Benzo(a)Pyrene for 30 days. The results obtained showed that M. maritypicum CB7 strain is able to degrade 69% of the initial amount of BaP. In order to improve the rate of biodegradation, we tested for 5 days the effect of a static magnetic field (SMF) at different inductions (50, 100 and 200 mT) on the degradation kinetics of Benzo(a)Pyrene by M. maritypicum CB7. Indeed, at 200 mT, we observed an increase of the yield by the twice of Benzo(a)Pyrene biodegradation rate compared to the non-induced sample. This study shows the important potential of M. maritypicum CB7 for the bioremediation of Benzo(a)Pyrene in the environment and the importance of the application of a SMF to yield the performance of the process suggesting its potential application in bioremediation of polluted sites with hydrocarbons compounds.

Molecular and phenotypic characterization of endophytic bacteria isolated from sulla nodules.

In the current study, bacterial diversity was investigated in root nodules of Sulla pallida and Sulla capitata. The isolates were analyzed on the basis of their phenotypic and molecular characteristics. The phylogenetic analysis based on 16S rRNA and housekeeping genes (recA and atpD) showed that the isolated bacteria related to Sinorhizobium, Neorhizobium, Phyllobacterium, Arthrobacter, Variovorax and Pseudomonas genera. This is the first report of Neorhizobium genus associated with Hedysarum genus. Phenotypically, all strains tolerate the elevated temperature of 40 °C, and salt stress at a concentration of 2%. In addition, the isolates failed to induce nodulation on their original host; and the symbiotic genes could not be amplified, suggesting that these strains are endophytic bacteria.

Influence of static magnetic field exposure on fatty acid composition in Salmonella Hadar.

We have been interested, in this work, to investigate the effect of the exposure to static magnetic field at 200 mT (SMF) on the fatty acid (FA) composition of Salmonella enterica subsp Enterica serovar Hadar isolate 287: effects on the proportion of saturated and unsaturated fatty acids (SFAs, UFAs), cyclopropane fatty acids (CFAs) and hydroxy fatty acids after exposure to the static magnetic field at 200 mT (SMF). Analysis with Gas Chromatography-Mass Spectrometry (GC-MS) of total lipid showed that the proportion of the most fatty acids was clearly affected. The comparison of UFAs/SFAs ratio in exposed bacteria and controls showed a diminution after 3 and 6 h of exposure. This ration reached a balance after 9 h of treatment with SMF. So we can conclude that S. Hadar tries to adapt to magnetic stress by changing the proportions of SFAs and UFAs over time to maintain an equilibrium after 9 h of exposure, thus to maintain the inner membranes fluidity. Also, a decrease in the proportion of hydroxy FAs was observed after 6 h but an increase of this proportion after 9 h of exposure. Concerning CFAs, its proportion raised after 6 h of exposure to the SMF but it decreased after 9 h of exposure. These results are strongly correlated with those of cfa (cyclopropane fatty acid synthase) gene expression which showed a decrease of its expression after 9 h of exposure.

Unraveling the expression of genes involved in the biosynthesis pathway of cardiolipin and phosphatidylethanolamine in Salmonella Hadar grown under static magnetic field 200 mT.

We aimed in this work to evaluate the effect of static magnetic field 200 mT (SMF) on the expression of genes involved in the biosynthetic pathway of cardiolipin: g3pd, plsB, cdsA, pgsA, pgpA, cls and phosphatidylethanolamine: pssA and psd in Salmonella enterica subsp enterica serovar Hadar. Bacteria were exposed to a SMF during 3, 6 and 9 h. RNA extraction was followed by Reverse Transcriptase Polymerase Chain Reaction RT-PCR. The relative quantification of mRNA expression levels using 16S rRNA doesn't change during the time exposure. RT-PCR was done for two exposure experiments. The gene expression using RT-PCR present no significant difference in case of plsB, cdsA, pgpA, pgsA and psd genes during the different exposure times. However, a significant increase was observed in the expression of g3pd and pssA genes after 6 h and for cls gene after 3 h of exposure, but any variation was notified after 9 h of exposure. So we can conclude from this study that cls, g3pd and pssA genes are required in the adaptation of Salmonella Hadar to SMF.

Enhancing blood donor skin disinfection using natural oils.

BACKGROUND: Effective donor skin disinfection is essential in preventing bacterial contamination of blood components with skin flora bacteria like Staphylococcus epidermidis. Cell aggregates of S. epidermidis (biofilms) are found on the skin and are resistant to the commonly used donor skin disinfectants chlorhexidine-gluconate and isopropyl alcohol. It has been demonstrated that essential oils synergistically enhance the antibacterial activity of chlorhexidine-gluconate. The objective of this study was to test plant-extracted essential oils in combination with chlorhexidine-gluconate or chlorhexidine-gluconate plus isopropyl alcohol for their ability to eliminate S. epidermidis biofilms. STUDY DESIGN AND METHODS: The composition of oils extracted from Artemisia herba-alba, Lavandula multifida, Origanum marjoram, Rosmarinus officinalis, and Thymus capitatus was analyzed using gas chromatography-mass spectrometry. A rabbit model was used to assess skin irritation caused by the oils. In addition, the anti-biofilm activity of the oils used alone or in combination with chlorhexidine-gluconate or chlorhexidine-gluconate plus isopropyl alcohol was tested against S. epidermidis biofilms. RESULTS: Essential oil concentrations 10%, 20%, and 30% were chosen for anti-biofilm assays, because skin irritation was observed at concentrations greater than 30%. All oils except for O. marjoram had anti-biofilm activity at these three concentrations. L. multifida synergistically enhanced the anti-biofilm activity of chlorhexidine-gluconate and resulted in the highest anti-biofilm activity observed when combined with chlorhexidine-gluconate plus isopropyl alcohol. Gas chromatography-mass spectrometry revealed that the main component contributing to the activity of L. multifida oil was a natural terpene alcohol called linalool. CONCLUSION: The anti-biofilm activity of chlorhexidine-gluconate plus isopropyl alcohol can be greatly enhanced by L. multifida oil or linalool. Therefore, these components could potentially be used to improve blood donor skin disinfection.

Role of Sod Gene in Response to Static Magnetic Fields in Pseudomonas aeruginosa.

The protective role of superoxide dismutase (SOD) against non-ionizing radiation such as static electromagnetic field (200 mT) has been studied in wild-type and mutant strain of Pseudomonas aeruginosa lacking cytosolic Mn-SOD (sodM), Fe-SOD (sodB), or both SODs (sodMB). Our results showed that inactivation of sodM and/or sodB genes increases the sensitivity of P. aeruginosa toward stress induced by the static magnetic field (200 mT). Furthermore, our results showed an enhancement of SOD, catalase, and peroxidases after exposure to the magnetic field. However, wild-type cells maintained significantly higher activities of antioxidant enzymes than mutant strains. The malondialdehyde produced by the oxidative degradation of unsaturated lipids and fatty acids showed significant increase in mutant strains compared to the wild-type. The overall results showed that the SOD has a protective role against a stress induced by static electromagnetic field in P. aeruginosa.

UV-C Adaptation of Shigella: Morphological, Outer Membrane Proteins, Secreted Proteins, and Lipopolysaccharides Effects.

Water UV disinfection remains extremely important, particularly in developing countries where drinking and reclaimed crop irrigation water may spread devastating infectious diseases. Enteric bacterial pathogens, among which Shigella, are possible contaminants of drinking and bathing water and foods. To study the effect of UV light on Shigella, four strains were exposed to different doses in a laboratory-made irradiation device, given that the ultraviolet radiation degree of inactivation is directly related to the UV dose applied to water. Our results showed that the UV-C rays are effective against all the tested Shigella strains. However, UV-C doses appeared as determinant factors for Shigella eradication. On the other hand, Shigella-survived strains changed their outer membrane protein profiles, secreted proteins, and lipopolysaccharides. Also, as shown by electron microscopy transmission, morphological alterations were manifested by an internal cytoplasm disorganized and membrane envelope breaks. Taken together, the focus of interest of our study is to know the adaptive mechanism of UV-C resistance of Shigella strains.