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In the present study, the ratio of reducing to oxidizing (F/O) elements as an indicator for maximum oxygen interference during the solution combustion synthesis (SCS) process of ZnO particles was determined using simple mathematical calculations. The obtained result was called special point (S.P). To interpret the role of S.P in the SCS reactions, ZnO particles were synthesized in the presence of citric acid, hexamine, hydrazine, and urea with various F/O values (0.75, 1, 1.25). The correlations between the S.P, physicochemical properties of the synthesized ZnO powders, and density functional theory (DFT) predictions were investigated. X-ray diffraction results, band-gap values, oxygen vacancy data, DFT results, and S.P points demonstrated the direct relation of these parameters. According to the S.P idea, it can be affirmed that the structural defects, particle size, optical band-gap (Eg = 3.06), the color of the products, the magnetic properties (0.2 emu/g), and the antibacterial inhibitory (15.625 µg/mL) of the synthesized particles were controlled via the interference of O2 during the synthesis process. In fact, the S.P investigation was suggested that the reaction rate of the combustion synthesis process could regulate the properties of ZnO particles.

Current arsenic analysis methods in groundwater samples rely on expensive apparatus, complicated procedures, and dangerous chemical reagents. Also, delays in detecting arsenic harm to public health, the environment, agriculture and food sectors. Therefore, in this study, a bioluminescent biosensor has been optimized and used to detect and measure arsenic concentration in groundwater. Optimum conditions for the appropriate performance of E. coli DH5α (pJAMA-arsR) were determined and the luminescent calibration curve was drawn. The optimization results showed that maximum luminescent light output could occur at the end of the logarithmic phase or the beginning of the stationary phase, the temperature of 37 °C, and pH between 5.5 and 7 upon adding 10 μl n-decanal (18 mM). Increasing the duration of bacterial induction by arsenic leads to elevation of biosensor luminescent light yield. Functional stability of the biosensor with 20 % glycerol (V/V) at −20 °C was verified for at least six months. Luminescence reaction of the bacterial biosensor cells to arsenic concentration in the range of 0–90 ppb was promising (R2 = 0.948 by linear regression), but higher arsenic concentration had poisonous effect on biosensor cells. The modified Gompertz model derived here could successfully predict the bacterial biosensor growth under the optimum condition compared with experimental data. In this study critical challenges, such as technical and appropriate performance, are defined to interpret the bacterial biosensor’s true perspective to promote its broad adoption and usage. The work is concluded with closing remarks and potential perspectives to emphasize the importance of the bacterial biosensor, which could detect arsenic from a wide scope in real-time, quickly, and environmentally friendly signaling tool with high sensitivity and selectivity.

Herein, two sunlight responsive photocatalysts including TiO2 nanoparticles (NPs) and TiO2/graphene quantum dots (GQDs) nanocomposite for degrading a textile dye, Reactive Black 5 (RB5), were prepared. The results showed that 100% of 50 ppm RB5 could be degraded by TiO2 NPs and TiO2/GQDs within 60 and 30 min sunlight irradiation, respectively. Hence, much better photocatalytic activity in degradation of RB5 was achieved by TiO2/GQDs under sunlight irradiation compared with pure TiO2 NPs due to its lower band gap (2.13 eV) and electron/hole recombination rate. The photocatalytic degradation mechanism of RB5 by TiO2 NPs was elucidated by adding some scavengers to the solution. The main reactive species contributing to RB5 degradation were surface hydroxyl radicals. The first-order solar degradation rate constant of RB5 for TiO2/GQDs is greater than that of TiO2 NPs under sunlight illumination.

A straightforward approach for the regioselective synthesis of various derivatives of benzo[e]pyrazolo[5′,1′:2,3]pyrimido[4,5-b] [1, 4] diazepine as a novel heterocyclic system from the annulation of 6-bromo-7-chloro-3-cyano-2-(ethylthio)-5-methylpyrazolo[1,5-a]pyrimidine with several 2-amino-N-substituted benzamides as bident nucleophiles in the presence of K2CO3 and DMF has been disclosed. The right regioisomer was elucidated by 2D-NOESY NMR spectroscopy, as well. Most of the novel synthetic compounds exhibited antimicrobial activity though relatively at high concentrations against multi-drug-resistant Klebsiella pneumoniae and Escherichia coli clinical isolates possessed of strong biofilm formation ability. N-Cyclohexyl-substituted pyrazolopyrimidobenzodiazepine (3 h) as the most potent compound represented 100% growth inhibitory on both types of bacterial strains, which brings promises for further changes to develop potential antimicrobial drugs.

High antibacterial and photocatalytic Ni0.5Zn0.5Fe2O4 nanoparticles were synthesized via solution combustion synthesis method using complex fuels i.e. glycine & urea. Employing a mixed-fuel system for synthesis of nanopowders improved the photodegradation of methylene blue as dye molecule to 85% along with 100% growth inhibition against bacteria (E. coli and S. aureus). The minimum inhibitory concentration of particles was 0.25 mg/mL and 0.125 mg/mL against the gram-negative and gram-positive bacterium, respectively. The effect of fuel type (glycine & urea), fuel to oxidizer ratio (φ = 0.8, 1, and 1.4), and complex fuels (mixing urea and glycine with different molar proportions) on the synthesis process as well as the physicochemical properties of the as-synthesized nanopowders were investigated. XRD, FTIR, EDS, and elemental mapping results implied that the formation of single-phase product relied on the φ value. Well-crystalline single-phase Ni0.5Zn0.5Fe2O4 particles with an estimated crystallite size of 8.9-22.4 nm, were synthesized at φ=0.8 and 1.4. Combusted particles using urea at φ = 1.4 displayed saturation magnetization of 67 emus/g (without further sintering process), the specific surface area of 150 m2/g, and particle size around 30 nm.

Azo dyes are an important group of recalcitrant xenobiotics, which are difficult to degrade and deteriorate in cold environments. In this study, two microbial consortia consisting of cold-adapted and mesophilic bacteria were developed for effective decolorization of Reactive Black-5 azo dye. These bacteria were isolated from textile wastewater and soil of a cold region. Identification of bacterial isolates using 16s rRNA gene analysis revealed that they belong to genus Pseudoarthrobacter, Gordonia, Stenotrophomonas, and Sphingomonas. Decolorization assay was performed for every strain at dye concentrations of 25, 50 and 100 mg/L and the consortia PsGo consisting of mesophilic bacteria and StSp consisting of cold-adapted bacteria were constructed accordingly. Results showed that the consortia PsGo and StSp were able to decolorize 54 and 34 percent of RB-5 (50 mg/L) during 7 days. To improve the dye removal efficiency of the consortia, several parameters including temperature, pH, carbon and nitrogen sources were optimized. Over longer periods, StSp consortium managed to completely decolorize RB-5 (50 mg/L) at optimized conditions of 25–30 °C, pH 9, and using glucose and NH4H2PO4 as carbon and nitrogen source respectively, whereas PsGo consortium decolorized RB-5 (50 mg/mL) completely at 37 °C, pH 11, and with lactose and NH4H2PO4 used as carbon and nitrogen sources. Kinetic of reactions for StSp and PsGo consortia were found to be 0.05 and 0.13 day−1 respectively, but became 0.71 and 0.9 day−1 after optimization. In general, cold ecosystems are good sources for the isolation of novel bacterial strains with a potential application, especially when used as consortia, in environmental biotechnology such as decolorization of RB-5.

Herein, two sunlight responsive photocatalysts including TiO

Although traditional antibiotic therapy provided an effective approach to combat pathogenic bacteria, the long-term and widespread use of antibiotic results in the evolution of multidrug-resistant bacteria. Recent progress in nanotechnology offers an alternative opportunity to discover and develop novel antibacterial agents.A total of 51 K. pneumoniae strains were collected from several specimens of hospitalized patients and identified by two parallel methods (biochemical tests and Vitek-2 system). The antibiotic sensitivity of isolates was evaluated by disk diffusion antibiogram and Vitek-2 system. The biofilms formation ability of antibiotic-resistant strains was examined by microtiter plate and tube methods based on crystal violet staining. The molecular technique was used to determine key genes responsible for biofilms formation of clinical isolates. The antibacterial and antibiofilm activities of Ag NPs, Ni NPs, AlThe results of bacterial studies revealed that more than 80 % of the isolates were resistant to commonly used antibiotics and about 95 % of them were able to form biofilms. Moreover, the presence of fimA and mrkA genes were determined in all biofilm-producing strains. The results of antibacterial and antibiofilm activities of NPs and cNPs demonstrated the lower MIC and MBEC values for AlIn the present study, the combination of Ag NPs, Ni NPs, and Al

Biosynthesis of silver nanoparticles (AgNPs) by marine bacteria especially luminescent Vibrio species is least investigated. In this study, AgNPs were first synthesized by the culture supernatant of a luminescent bacterium (Vibrio sp. B4L) and then, the prepared samples were characterized employing several techniques. The antibacterial activity of the AgNPs was investigated against Escherichia coli and Staphylococcus aureus using disk diffusion agar and broth microdilution methods. The growth curve, Reactive Oxygen Species (ROS) formation, and Lactate Dehydrogenase (LDH) activity of the samples were measured along with Field Emission Scanning Electron Microscopy (FESEM) observation and inhibition of biofilm formation. Dynamic light scattering (DLS) analysis showed that the average particle size of the synthesized AgNPs was in the range of about 32.67–107.18 nm and the polydispersity index (PDI) of 0.1120 indicated the formation of monodispersed particles. The average zeta potential of AgNPs obtained −36.15 mV, showing the high stability of biosynthetic nanoparticles. Antibacterial studies indicated that not only the AgNPs had antibacterial activity but also increased the antibacterial properties of tetracycline when used in combination. ROS production was enhanced in a dose-dependent manner. A high difference in LDH activities was found between AgNPs treated cells and the control group. FESEM images revealed membrane disruption and lysis in AgNPs treated cells. The formation of E. coli biofilm was 100% inhibited at 62.5 µg/ml showing that our bacteriogenic AgNPs can be a potential alternative remedies for controlling antibiotic-resistant pathogens.

Trigonella foenum-graecum (fenugreek) is a leguminous plant that produces secondary metabolites frequently used in medicinal and food preparation. Here, the role of an arbuscular mycorrhizal (AM) fungal inoculum, alone or in combination with methyl jasmonate (MeJA) chemical treatment, was evaluated on the production of trigonelline and diosgenin in fenugreek plants grown under mild water limitation. After inoculation, fenugreek plants were subjected to several combined treatments, i.e. well-watered (NS) and water-stressed (WS), both treated with different MeJA concentrations (0, 50, 100, 200 mL/L). At the end of the experiment, in addition to trigonelline and diosgenin content, an array of plant growth parameters (i.e. fruit, stem and root dry weights, fruit number) and biochemical stress markers (i.e. proline, nitric oxide, hydrogen peroxide, MDA) were examined. Results mainly showed a significant increase in production of the considered secondary metabolites, although they are differentially influenced by the individual factors (Stress, SYM, MeJA) and their interactions. SYM treatment was more effective on the production of trigonelline, independently from growth conditions, while diosgenin biosynthesis was influenced by the presence of root symbioses only in combination with MeJA treatment. A differential impact, depending on the applied treatment (inoculum, MeJA treatments, water deficit), on plant growth and on production of the considered bioactive molecules was revealed, providing new information on the effect of biological and chemical priming treatments.

The present study reflected on high-priority biological activities of novel silver nanoparticles (AgNPs) synthesized via two cold-tolerant strains; namely, Streptomyces sp.OSIP1 and Streptomyces sp.OSNP14. These AgNPs were synthesized through a green method using culture supernatant of bacteria at 20 °C and characterized by several instrumental techniques. The TEM results revealed that the NPs obtained from OSIP1 were smaller (8 nm, average) than those taken from OSIP14 (15 nm, average). Both AgNPs-OSP1 and AgNPs-OSNP14 also posed the strongest growth inhibitory effect against several pathogenic bacteria alone and especially in combination with antibiotics. Smaller NPs especially at 3.9–31.25 µg/ml concentrations were assumed more effective biofilm inhibitors of Pseudomonas aeruginosa. Cytotoxic activity of both AgNPs (at 25 and 50 µg/mL concentrations) on mouse colorectal carcinoma cells (CT26) were then studied using methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay. The findings demonstrated that smaller AgNPs at a 50 µg/mL concentration had 7% more cytotoxicity effects. In conclusion; although AgNPs produced by diverse strains of cold-adapted Streptomyces had close characteristics and biological activities, they showed some multifarious properties.

Bacteria-directed enzyme prodrug therapy (BDEPT), is an emerging alternative directed and tumor-specific approach. The basis of this method is the conversion of a non-toxic prodrug by a bacterial enzyme to a toxic drug within the tumor-microenvironment (TME). In the present study, the therapeutic efficacy of BDEPT was investigated based on the ability of Escherichia coli DH5α-lux/βG in activation of glycyrrhizic acid (GL), a natural and non-toxic compound purified from licorice, to glycyrrhetinic acid (GA) only in TME. To do so, the anti-bacterial effects of GL on bacteria and the cytotoxic effects of the produced GA on survival rate of CT26 mouse colon carcinoma cells were evaluated. The IC50 values of the produced GA and cisplatin were determined as 210 μM and 100 μM, respectively. Comparing these values to GL treatment (1305 μM) indicates that bacteria could have efficiently activated GL to GA to inhibit the growth of tumor cells. Afterward, the anti-cancer effects of bacteria used in combination with GL was investigated in a mouse model of colon carcinoma. Results were indicative of targeted homing and even proliferation of luminescent bacteria in TME. Moreover, combined treatment greatly inhibited tumor growth. Histopathological analysis of dissected tissues also demonstrated increased apoptosis rate in tumor cells after combined treatment and interestingly, showed no obvious damage to the spleen and liver of treated mice. Accordingly, this BDEPT approach could be considered as an effective alternative tumor-specific therapy utilizing prodrug-activating enzymes expressing from tumor-targeting bacteria to allow the development of new tumor-specific pharmacotherapy protocols.

Halophiles are the organisms that thrive in extreme high salt environments. Despite the extensive studies on their biotechnological potentials, the ability of halophilic prokaryotes for the synthesis of nanoparticles has remained understudied. In this study, the archaeal and bacterial halophiles from a solar saltern were investigated for the intracellular/extracellular synthesis of silver and selenium nanoparticles. Silver nanoparticles were produced by the archaeal Haloferax sp. (AgNP-A, intracellular) and the bacterial Halomonas sp. (AgNP-B, extracellular), while the intracellular selenium nanoparticles were produced by the archaeal Halogeometricum sp. (SeNP-A) and the bacterial Bacillus sp. (SeNP-B). The nanoparticles were characterized by various techniques including UV-Vis spectroscopy, XRD, DLS, ICP-OES, Zeta potentials, FTIR, EDX, SEM, and TEM. The average particle size of AgNP-A and AgNP-B was 26.34 nm and 22 nm based on TEM analysis. Also, the characteristic Bragg peaks of face-centered cubic with crystallite domain sizes of 13.01 nm and 6.13 nm were observed in XRD analysis, respectively. Crystallographic characterization of SeNP-A and SeNP-B strains showed a hexagonal crystallite structure with domain sizes of 30.63 nm and 29.48 nm and average sizes of 111.6 nm and 141.6 nm according to TEM analysis, respectively. The polydispersity index of AgNP-A, AgNP-B, SeNP-A, and SeNP-B was determined as 0.26, 0.28, 0.27, and 0.36 and revealed high uniformity of the nanoparticles. All of the synthesized nanoparticles were stable and their zeta potentials were calculated as (mV): -33.12, -35.9, -31.2, and -29.34 for AgNP-A, AgNP-B, SeNP-A, and SeNP-B, respectively. The nanoparticles showed the antibacterial activity against various bacterial pathogens. The results of this study suggested that the (extremely) halophilic prokaryotes have great potentials for the green synthesis of nanoparticles.

Graphene-Fe3O4 (G-Fe3O4) nanocomposites with different GO/Fe3O4 weight ratios of 1-1, 1–3 and 1–5 were synthesized using solvothermal method. Also, Fe3O4 nanoparticles (NPs) were separately synthesized by the same method. The prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. Zeta potential analysis and scanning electron microscopy (SEM) were employed to measure the surface charge and the destruction processes of the bacteria. The XRD analysis showed that the graphene oxide had been reduced and also confirmed the formation of G-Fe3O4 nanocomposites. The antibacterial properties of the prepared samples were investigated against Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) strains, using three different methods. Our results revealed that the G-Fe3O4 with 1–5 wt ratio has higher antibacterial activity and lower toxicity, compared to the other two nanocomposite samples, GO and also Fe3O4 NPs.

In this paper, the photocatalytic activity of TiO2 NPs was improved twice: the first by engineering its morphology to narrow the band gap and to increase the surface area and the second by incorporating the modified TiO2 NPs with graphene quantum dots (GQDs) to reduce electron-hole ( e − h + ) recombination rate. Three visible/solar light responsive photocatalysts including TiO2 nanoparticles (NPs) and two nanocomposites of TiO2 @ GQDs were prepared. The photocatalytic activity of the prepared photocatalysts, GQDs, and P25 against Rhodamine B (RhB) under visible light or sunlight radiation was investigated. The prepared TiO2 NPs possessed very small particle size of 7.62 nm, large surface area of 236 m2 g−1, and narrow band gap of 2.41 eV. TiO2 NPs could harvest the visible/solar light for degrading RhB. The photocatalytic activity of TiO2 @ GQDs nanocomposites prepared by hydrothermal and ultrasound methods under visible light radiation are much better than that of TiO2 NPs. Using PL spectra, it was found that GQDs in the nanocomposites can hinder (or delay) e − h + recombination and hence improve the photocatlytic performance of TiO2 NPs. The photocatalytic degradation of RhB over TiO2 NPs and TiO2 @ GQDs nanocomposites prepared by hydrothermal and ultrasound methods under visible light radiation followed the pseudo-first-order kinetics with the rate coefficients of 0.126, 0.170, and 0.149 min−1, respectively.

Theranostic nanoparticles have attracted considerable attention in recently revolutionized medicine. Since the last decade, there has been a growing attempt to design various theranostic nanoparticles but difficulties still exist in the fabrication of their biocompatible one. Herein, fluorescent titania nanoparticles (FTN) were fabricated using a one-step green method. This FTN had ultra-high doxorubicin hydrochloride (DOX) loading capacity (encapsulation efficiency 95.50% and loading content 38.20%) that release the loaded drug in response to acidic pH. In vitro cytotoxicity experiments on human osteosarcoma (SaOs-2) and breast cancer (MCF-7) cell lines revealed superior anticancer efficacy (lowered the IC

Background Although traditional antibiotic therapy provided an effective approach to combat pathogenic bacteria, the long-term and widespread use of antibiotic results in the evolution of multidrug-resistant bacteria. Recent progress in nanotechnology offers an alternative opportunity to discover and develop novel antibacterial agents. Methods A total of 51 K. pneumoniae strains were collected from several specimens of hospitalized patients and identified by two parallel methods (biochemical tests and Vitek-2 system). The antibiotic sensitivity of isolates was evaluated by disk diffusion antibiogram and Vitek-2 system. The biofilms formation ability of antibiotic-resistant strains was examined by microtiter plate and tube methods based on crystal violet staining. The molecular technique was used to determine key genes responsible for biofilms formation of clinical isolates. The antibacterial and antibiofilm activities of Ag NPs, Ni NPs, Al2O3 NPs singly (NPs) and in combination (cNPs) were investigated against selected strains using standard methods. Moreover, the cytotoxicity of NPs was evaluated on mouse neural crest-derived (Neuro-2A) cell line. Results The results of bacterial studies revealed that more than 80 % of the isolates were resistant to commonly used antibiotics and about 95 % of them were able to form biofilms. Moreover, the presence of fimA and mrkA genes were determined in all biofilm-producing strains. The results of antibacterial and antibiofilm activities of NPs and cNPs demonstrated the lower MIC and MBEC values for Al2O3 NPs singly as well as for Ag/Ni cNPs and Ag/Al2O3 cNPs in combination, respectively. Overall, the inhibitory effects of cNPs were superior to NPs against all strains. Furthermore, the results of the checkerboard assays showed that Ag NPs act synergistically with two other NPs against multidrug-resistant Klebsiella pneumoniae (MDR-K. pneumoniae) isolates. The in vitro cytotoxicity assay revealed no significant toxicity of NPs against Neuro-2A cells. Conclusion In the present study, the combination of Ag NPs, Ni NPs, and Al2O3 NPs were used against MDR-K. pneumoniae strains and antibacterial and antibiofilm activities were observed for Ag/Ni cNPs and Ag/Al2O3 cNPs.

In this study, the bactericidal properties of the wing surface of two different Psalmocharias cicada species, Psalmocharias querula (PQ) and Psalmocharias akesensis (PA), are examined based on the organization and nano-topographical characteristics of the wing nanostructure. The bacterial killing capacity of the wings was assessed by counting the colony-forming units (CFU). Atomic force microscopy (AFM), scanning electron microscopy (SEM), and contact angle measurements were utilized to reveal wings nano-topographical structures and their impact on bacterial contact-killing efficiency. The role of surface roughness parameters on bacterial cell attachments and bactericidal properties of the wings was evaluated by analysis of topography results using histogram height distribution and power spectral density (PSD) methods. It was found that the skewness and kurtosis values of the cicada wing nanopillars significantly correlate with their shear-inducing capacity, confirming the higher bactericidal activity for PQ wing surface compared to PA wing surface.

The introduction of novel bacterial strains and the development of microbial approaches for nanoparticles biosynthesis could minimize the negative environmental impact and eliminate the concern and challenges of the available approaches. In this study, a biological method based on microbial cell-free extract was used for biosynthesis of ZnO NPs using two new aquatic bacteria, Marinobacter sp. 2C8 and Vibrio sp. VLA. The synthesized ZnO NPs were characterized by UV–Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscope (AFM), dynamic light scattering (DLS) and zeta potential. The UV–Visible absorption peak was found to be at 266 and 250 nm for ZnO-2C8 NPs and ZnO-VLA NPs, respectively. FTIR study suggested that the hydroxyl, amine, and carboxyl groups of bacterial proteins are mainly responsible for stabilizing the biosynthesized ZnO NPs. The formation of hexagonal wurtzite structure of ZnO NPs was confirmed by the XRD pattern. The morphology of the nanoparticles was found to be spherical with the average particle size of about 10.23 ± 2.48 nm and 20.26 ± 4.44 nm for ZnO-2C8 NPs and ZnO-VLA NPs, respectively. The values of zeta potential indicate the high stability of the biosynthesized ZnO NP. Zeta potential values indicated the high stability of the biosynthesized ZnO NP and were obtained −20.54 ± 7.15 and –23.87 ± 2.29 mV for ZnO-2C8 NPs and ZnO-VLA NPs, respectively. The biosynthesized ZnO NPs had antibacterial activity against Gram-negative and Gram-positive strains and possessed excellent antibiofilm activity with the maximum inhibition of about 96.55% at 250 µg/mL. The DPPH activity of ZnO-2C8 NPs and ZnO-VLA NPs were found 88.9% and 85.7% for 2500 μg/mL concentration, respectively. The toxicity test revealed the biocompatibility of the biosynthesized ZnO NPs. The results suggested that this approach is a very good route for synthesizing ZnO NPs with potential applications in biotechnology.

There is considerable evidence to increase diosgenin and other medicinally useful compounds production in fenugreek with microbial inoculations. Fenugreek (Trigonella foenum-graecum L.), as an annual medicinal plant, is extensively cultivated in most regions of the world. In the present study we evaluate the role of plant growth-promoting rhizobacteria (PGPR) inocula (Pseudomonas putida and Bradyrhizobium japonicum) alone or in combination with an arbuscular mycorrhizal fungus(AMF) (Glomus intraradices) on diosgenin content, some biochemical characteristics and phosphorus accumulation of fenugreek plants subjected to drought stress. ACC deaminase activity was detected in both bacteria and it was 2.1 fold higher in B. japonicum than the P. putida. Results showed that diosgenin content was commonly higher in leaves under non-stress vs drought stress condition. In non-stress, plants with dual inoculation (G. intraradices and B. japonicum) resulted in highest diosgenin content significantly different with other treatments. The leaf proline content was the highest in plant subjected to drought stress with dual inoculation (G. intraradices and P. Putida), whereas the highest total soluble proteins was belonged to plants with triple inoculation(P. putida, B. japonicum and G. intraradices). Bacterial and fungal inoculation decreased peroxidase activity both in stress and non-stress condition. The highest amount of phosphorous in the roots was assigned to single inoculation with P. putida in stress and with G. intraradices in non-stress condition. The present study provides a good insight on the effect of PGPR and AMF on diosgenin content as a major bioactive constituent.

In this work, fluorescent copper oxide nanoparticles (CuO NPs) were green synthesized using viable cells, cell lysate supernatant (CLS) and protein extracts of luminescent Vibrio sp. VLC. Biogenic CuO NPs were then characterized by XRD, FTIR, UV/Vis spectroscopy, TEM, DLS, and PL spectroscopy. Results showed that CLS method was more efficient for CuO NPs production, therefore CuO NPs synthesized by this method from copper sulfate (CuO NPs-1) and/or copper nitrate (CuO NPs-2) were used for further studies. The crystallite size of polydispersed CuO NPs-1 and CuO NPs-2 were about 8.83 and 8.77 nm, respectively indicating their suitability for biological applications. Antibacterial activity of CuO NPs was determined using broth microdilution, well diffusion agar, and time-kill curves methods. Both CuO NP-1 and CuO NP-2 inhibited bacterial growth at the minimum inhibitory concentration (MIC) of 625 mg/L except St. mutants (MIC = 1250 mg/L). Emission of fluorescent light from the surface of NPs was increased when exposed to Cd2+, As2+ and Hg2+ ions but decreased by Pb2+ ions. Results showed that CuO NP-1 had anticancer properties against KYSE30 esophageal cancer cell line (IC50 = 13.96 mg/L) while no higher cytotoxic effects were observed on Human Dermal Fibroblasts (HDF) (IC50 = 48.88 mg/L).

Microbial mediated biological synthesis of nanoparticles is of enormous interest to modern nanotechnology due to its simplicity and eco-friendliness. In the present study, a novel green method for the synthesis of platinum nanoparticles (PtNPs) has been developed using bio-derived product-cell lysate supernatant (CLS) from various microorganisms including Gram-negative bacteria: Pseudomonas kunmingensis ADR19, Psychrobacter faecalis FZC6, Vibrio fischeri NRRL B-11177, Gram-positive bacteria: Jeotgalicoccus coquinae ZC15, Sporosarcina psychrophila KC19, Kocuria rosea MN23, genetically engineered bacterium: Pseudomonas putida KT2440 and yeast: Rhodotorula mucilaginosa CCV1. The biogenic PtNPs were characterized by UV–visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), and atomic force microscopy (AFM). The UV–visible spectra showed a red shift in the absorbance of H2PtCl6.6H2O from 260 nm to 330 nm for all prepared PtNPs. The XRD patterns of the samples indicated the formation of high purity of the cubic phase. The FTIR spectra and EDS profiles of the samples demonstrated the existence of proteins on fabricated and stabilized PtNPs. The TEM and AFM images analysis showed the synthesis of smallest PtNPs by a bacterium strain (FZC6) and yeast while genetically engineered bacteria produced the largest NPs. Also, the HRTEM analysis showed the high crystallinity of PtNPs and the interplanar spacing of 0.2 nm, corresponds to the (1 1 1) of plane of PtNPs. The results of zeta potential indicated the high stability of PtNPs in neutral pH. Moreover, the suitability of PtNPs antioxidant and antibacterial activity was correlated to the size and zeta potential of microbe used for NPs biosynthesis. In conclusion, it was found that the type of microorganisms can have influences on PtNPs characteristics and properties as Gram-negatives produced smaller PtNPs while more negatively charged NPs were obtained by Gram-positives. These findings could facilitate the selection of appropriate green approaches for more effective biotechnological production of PtNPs.

A total of 422 bacterial isolates were obtained from the lead (Pb) ore in north-eastern Iran. The Pb tolerances of these strains were studied using microbroth serial dilution approach and 35 strains could grow up to 3250 ppm Pb concentration. Of these strains, 10 of them represented qualitatively high levels of Pb adsorption and were selected for quantitative studies. Strain AS2 which is phylogenetically related to genus Bacillus showed the highest level of Pb remediation. The effects of different factors, including pH, initial Pb concentration, temperature and inoculum size, were studied on the remediation process. Pb remediation capacity was reached at 74.5 mg/g (99.5 % of initial Pb) at pH 4.5, temperature 30 °C, inoculum size 1.0 % (v/v) and an initial Pb concentration of 500 ppm after 24 h. Pb desorption capacity of strain was 66 %. The novel isolate could remove 98 % of Pb from the contaminated industrial wastes after 24 h. Pb uptaking to the cell surface was proven using scanning electron microscopic micrograph and energy-dispersive X-ray spectroscopy analysis. Most Pb removal efficiency was observed in the active cell culture as compared to the inactive cell and extracellular polymeric substances. The novel strain represents a good candidate for removal of environmental anthropogenic Pb pollutions.

Treated fish wastes have found many applications in industry and medicine. Besides, nowadays low-cost scaffold with antimicrobial activity which can accelerates the process of wound healing is very demanding. In this study fish swim bladder (FSB), taken from Rutilus frisii, which is a disposable waste was doped with silver nanoparticles (AgNPs) and evaluated as antimicrobial wound dressing. The scanning electron microscopy (SEM) micrographs showed the presence of AgNPs on the scaffold. Histological observation confirmed cells and muscle removal from FSB and collagen preservation. There was significant antibacterial activity even in 50 ppm AgNPs concentration against pathogenic bacteria, swelling ratio was rather low, and cytotoxic assay revealed that the AgNPs-FSB scaffold had no toxic effect on human foreskin fibroblast (HFF) cells. Interestingly, despite the porous structure, the AgNPs-FSB scaffold was found to be a suitable barrier to microbial penetration even after 72 h. Further study showed the gradual release of AgNPs during 24 h. In conclusion, biofabricated FSB prepared in this study have appropriate characteristics notably encompassing a high quantity of collagen and broad-spectrum antimicrobial activity. Also, its porous structure made it suitable as a 3-D structure for the growth of cells and adding other antimicrobial nano-sized materials.

In this study, a biologically active mixed-valence V(IV)/V(V) complex [VO(Hofloz)2(H2O)][V4O12]0.5.6H2O (1) (Hofloz = zwitterionic isomer of ofloxacin) was synthesized by the reaction of VOSO4 with ofloxacin (Hofloz) in presence of KOH with 1:1:1 ratio. The complex was characterized through the usage of elemental analysis, FT-IR, molar conductivity and single-crystal X-ray diffraction and thermogravimetric analysis (TGA). The results of single crystal X-ray structure determination revealed an ionic structure consisting of [VO(Hofloz)2(H2O)]2+ and [V4O12]4− units with 1:0.5 stoichiometry. The V+4 ion in the cationic unit has octahedral geometry while each V+5 ion of the eight-member cyclic tetravanadate anion is tetrahedrally coordinated. In regards to the crystal structure of 1, the bidentate ofloxacin ligand is coordinated to the V+4 ion in its zwitterionic form (+HN–···–COO-) through the oxygen atoms of the pyridone and carboxylato groups. The thermodynamic stability of two isomeric forms of Hoflo and 1 along with their charge distribution patterns was studied by DFT and NBO analysis. Also, the ability of the ligand to interact with ten selected biomacromolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS, Top II and B-DNA) was investigated by docking calculations. These studies revealed that this ligand can bind to the proteins and DNA molecule and could be consider as biologically active compound. Finally, the antibacterial activities of the free Hoflo ligand and its vanadium complex have been evaluated against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) strains through the utilization of broth microdilution and well diffusion methods. The complex showed antibacterial effect similar to the free Hoflo ligand on the selected bacterial strains and these compounds were more active against Gram-negative bacteria.

The use of nanotechnology for nanobacteria (or calcifying nanoparticles) treatment is a new creative approach. Use of selenium nanoparticles (SeNPs) as anti-nanobacterial agents might be considered as a bright promising approach due to their critical role in the inhibition of crystal growth and aggregation of calcium oxalate. Hence, in this study, we investigated the probable outcome of SeNPs inhibitory effects on growth of nanobacteria. Fragments of thirty urinary tract stones were chemically analyzed by X-ray diffraction (XRD) and urinary stones Kits for calcifying nanoparticles presence. Then powder of stone fragments were resuspended in Dulbecco's modified Eagle's medium (DMEM), sterilized by filtration and cultured in presence of 1, 5, 30, 60, and 90 μmol/L SeNPs concentrations. Besides, calcifying nanoparticles growth in the culture without SeNPs was measured spectrophotometrically. Also, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses were used, where calcifying nanoparticles formation occurred. Results showed that in the culture without SeNPs, the positive calcifying nanoparticles detection was 60% while after adding SeNPs at 90 μmol/L, not any calcifying nanoparticles were observed. Further confirmation came out when Energy-dispersive X-ray (EDX) analysis showed calcium and phosphate peaks in the culture medium without any SeNPs while in the culture containing 90 μm/L SeNPs a decrease in calcium and other minerals was obvious. Therefore, SeNPs clearly restricted the growth of nanobacteria due to their inhibitory effects on calcium oxalate deposition.

Background and Objectives: Arginine-rich peptides are an important class of antimicrobial peptides (AMPs) that exert their antibacterial activity via a lytic mechanism. Although the antibacterial activity of arginine-rich peptides has been already evaluated, no reports have so far been evaluated the influence of reaction conditions on their antimicrobial potential. The aim of the present study was to investigate the influence of pH, temperature, and glycine on antibacterial activity of poly-l-arginine (PLA) with a molecular weight of 5-15 kDa against Escherichia coli O157:H7 and Staphylococcus aureus. Materials and Methods: The percentage of growth inhibition of PLA against both bacteria was analyzed at various pH, temperatures and sub-inhibitory concentrations of glycine by two-fold broth microdilution method. Results: The results showed that PLA had antibacterial activity against E. coli O157:H7 and S. aureus and the inhibitory effect increased with increasing PLA concentration. The antimicrobial activity of PLA against both microorganisms was higher in basic media than under acidic or neutral conditions. At 1/2 times the MIC, heat treatment intensified the toxicity of PLA against E. coli O157:H7 whereas the susceptibility to PLA seems to be temperature independent for S. aureus. The MICs of glycine against E. coli O157:H7 and S. aureus were 12.5 and 25 mg ml-1, respectively. The antibacterial activity of PLA against both microorganisms increased, as indicated by the increasing growth inhibition percentage of this peptide with increasing glycine concentration. Conclusion: The antibacterial activity of PLA against S. aureus and E. coli O157:H7 depends on pH and glycine concentration.

A novel halo-alkali and thermo-tolerant chitinase was obtained from an isolated strain found in the Caspian Sea. The effects of media composition and various fermentation conditions for the optimization of chitinase production were studied one factor at a time and by response surface methodology. The novel strain, which is designated as strain DC14 and phylogenetically related to the genus Pseudoalteromonas, produced chitinase after 72 h under the following optimal conditions: glucose 1 % (w/v), ammonium sulphate 0.2 % (w/v), chitin 1.07 % (w/v), pH 8, NaCl 10 % (w/v), inoculums size 2.5 % (v/v), temperature 30 °C, CaCl2 3 mM and MgCl2 4 mM. Using the statistical optimization method, chitinase production was found to increase from 2.30 to 21.90 U/dl. The enzyme showed maximum activity at 40 °C, pH 9 and 10 % NaCl. It was stable in a wide range of temperature from 15 to 65 °C, pH from pH 7 to 11 and NaCl concentration from 0 to 15 % (w/v). The molecular weight of the enzyme was estimated by SDS-PAGE to be about 65 kDa. With regard to the halo-alkali and thermo-stable properties of this enzyme, it has potential industrial activity.

The effect of different genetically engineered bacteria, Pseudomonas syringae, Pseudomonas savastanoi, and Ralostonia solanacerum and also a natural marine bacterial species, Vibrio fischeri NRRL B-11177, is studied in producing gold nanoparticles. This is the first report about the biosynthesis of gold nanoparticles by natural and genetically engineered luminescent bacteria. These microorganisms reduced gold ions and produced fairly monodisperse nanoparticles. TEM analysis indicated that spherical nano gold particles in the different diameters and shapes were obtained at pH values of 6.64. In this biosynthesis protocol, the gold nanoparticles with desired shape and size can be prepared.

Sol-gel method was successfully used for synthesis of ZnO nanoparticles doped with 10 % Mg or Cu. The structure, morphology and optical properties of the prepared nanoparticles were studied as a function of doping content. The synthesized ZnO:(Mg/Cu) samples were characterized using XRD, TEM, FTIR and UV-Vis spectroscopy techniques. The samples show hexagonal wurtzite structure, and the phase segregation takes place for Cu doping. Optical studies revealed that Mg doping increases the energy band gap while Cu incorporation results in decrease of the band gap. The antibacterial activities of the nanoparticles were tested against Escherichia coli (Gram negative bacteria) cultures. It was found that both pure and doped ZnO nanosuspensions show good antibacterial activity which increases with copper doping, and slightly decreases with adding Mg.

It has been proved that fresh frog skin is efficient in the wound healing process.The purpose of study is to introduce a formulation of frog skin powder for evaluation of wound repair where fresh frog skin is not available.Rana ridibunda (Ranidae) skins were lyophilized, and a powder was prepared. The powder (0.0005 g) was then mixed with ointment (0.0065 g) for treating each wound. Formulation was used on full-thickness wounds on mice (FO group) and compared to positive and negative controls. In order to study the wound healing process, wound contraction, inflammation, number of fibroblast cells, neovascularization and collagen density were evaluated on days 2, 4 and 6 following the injury. Moreover, CFU measurement was performed for the evaluation of wound contamination.Acceleration in wound contraction in the FO group compared to control groups was significant (p 0.001) on days 4 and 6. Results showed that FO treatment considerably decreased inflammatory cells during the study. On day 4, FO treatment was significantly effective in increasing the number of fibroblast cells and collagen density (p 0.01 and p 0.05, respectively). On day 6 the number of fibroblast cells (p 0.001), collagen density (p 0.05) and neovascularization (p 0.05), were higher in the FO group than the control groups. Results of CFU measurement demonstrated significant reduction of wound contamination in FO treated wounds on days 2 (p 0.05) and 4 (p 0.01).Our findings indicated that the pharmaceutical form of frog skin used in this study has considerable healing and antibacterial effects on wounds.

Ethnopharmacological relevance Study of the interrelationships between human and the animals in their environment has always been a subject of interest and caused discoveries of the animal applications in medicine. From the latest century, these remedies called back in traditional medicine of Vietnam and South America and frog skin was used as a biological dressing and had good effects in healing wounds. Also, frog skin secretions have wound healing properties and reduce inflammation. In this study we applied these secretions in the form of ointment to investigate their healing activities. Materials and methods Skin secretions were extracted from Rana ridibunda to evaluate their effects on wound healing in mice. Secretion used as raw extract (RE) and ultrafiltrated extract, using a membrane with cutoff 10 kDa as under 10 kDa (U10E), was administrated as ointment every 48 h on wound site. Control group was left without any treatment and also there was other group treated with ointment (O group) alone. On 2, 4 and 6 days post injury, animals were euthanized and images were taken for wound closure evaluation. Then wound locations were removed for histological assays. Also wound microbial load was examined. Observational parameters including wound closure and wound microbiology in experimental groups compared with the control and O groups have been studied. Results The results showed U10E group has better effects than RE, O and control groups. Histological parameters, including numbers of inflammatory and fibroblast cells and amount of collagen fibers, neovascularization, as well, represented greater degree of wound healing in U10E group compared with RE, O, and control groups. Conclusions Our results showed that frog skin secretions were significantly effective in promoting wound healing process. The U10E extract from the frog R. ridibunda possesses a potent accelerating wound healing effect that promises good potential for clinical application in wound care. Further studies will be required to characterize special molecules encompassing healing properties.

Potential of luminescent bacteria in production of metal nanoparticles has not been well evaluated up until now. These bacteria contain lux operon which is included of reductase enzymes, by increasing bacterial cell density, the expression of aldehyde synthetic enzymes elevate and enhance the yields of nanoparticles synthesis. Therefore, in this study extracellular synthesis of gold nanoparticles using natural occurring luminescent bacteria, VLA, VLB, VLC and genetically engineered luminescent bacteria, Pseudomonas putida KT2440 and Pseudomonas fluorescence OS8 has been successfully conducted. Nanoparticles were characterized and their antibacterial activity evaluated using microtiter plates at different concentrations against some hospital pathogenic bacteria .Biosynthetic gold nanoparticles produced in this study had maximum absorption at the ranges of 500 to 550 nanometer wavelengths. TEM images showed particle sizes between 10 to 50 nanometers and confirmed the success of purification process. The NPs were spherical and the FTIR analysis showed the existence of biomolecules on surface of purified nanoparticles that could be most probably related to reductase enzymes that is stabilized on nanoparticles surfaces. Further investigation on antibacterial properties of these novel nanoparticles which coated by reductase enzymes showed that any increase or decrease in antibacterial activity is depended on nanoparticles concentration.