Search

The authors report Myxobacteria virescens (M. virescens) mediated synthesis of silver nanoparticles (AgNPs) and its efficacy against Staphylococcus aureus (ATCC‐33591), Salmonella typhi (ATCC‐51812), Escherichia coli (E. coli) (ATCC‐14948), Klebsiella pneumoniae (MTCC‐4030) and Pseudomonas aeruginosa (MTCC‐4673). The organism exhibiting resistance to various antibiotics showed remarkable sensitivity, when used in combination of antibiotics and AgNPs. Antimicrobial property of AgNPs is playing a significant role in medicine and food storage. In this study, they have used M. virescens for the synthesis of AgNPs, which were characterised by using UV‐Vis spectrophotometer, nano‐particles tracking and analysis, zeta potential, Fourier transform infrared spectroscopy, X‐ray diffraction and transmission electron microscopy. Synthesised AgNPs were impregnated into paper by three different methods, i.e. glass rod method (without binder), glass rod method (with binder) and direct synthesis of AgNPs on paper. Nanoparticles synthesis on paper showed the significant antimicrobial activity against Staphylococcus aureus (ATCC‐33591), Salmonella typhi (ATCC‐51812), E. coli (ATCC‐14948), Klebsiella pneumoniae (MTCC‐4030) and Pseudomonas aeruginosa (MTCC‐4673). Paper impregnated with AgNPs was used for wrapping of fruits (apples) which increases their shelf life up to 15 days. This study demonstrates a new method for wrapping of fruits, which increases the shelf life of apples. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have been undeniable for its antimicrobial activity while its antitumour potential is still limited. Therefore, the present study focused on determining cytotoxic effects of AgNPs on Michigan cancer foundation‐7 (MCF‐7) breast cancer cells and its corresponding mechanism of cell death. Herein, the authors developed a bio‐reduction method for AgNPs synthesis using actinomycetes isolated from marine soil sample. The isolated strain was identified by 16s ribotyping method and it was found to be Streptomyces atrovirens. Furthermore, the synthesised AgNPs were characterised by various bio‐analytical techniques such as ultraviolet–visible spectrophotometer, atomic force microscopy, transmission electron microscopy, Fourier transform infra‐red spectroscopy, and X‐ray diffraction. Moreover, the results of 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay reveals 44.51 µg of AgNPs to have profound inhibition of cancer cell growth; furthermore, the inhibition of MCF‐7 breast cancer cell line was found to be dose dependent on treatment with AgNPs. Acridine orange and ethidium bromide double staining methods were performed for cell morphological analysis. The present results showed that biosynthesised AgNPs might be emerging alternative biomaterials for human breast cancer therapy. [ABSTRACT FROM AUTHOR]

In this examination, we researched the advantages of DNA fragmentation and metallic nanoparticles well‐appointed with biomolecules. A novel interpretation of DNA damage by Silver Nano‐Clusters (AgNCs) which were developed by the utilization of green synthesis method was demonstrated. The green synthesis of AgNCs was accomplished by utilizing the leaf extract of Salacia mulbarica (SM). The preparation of SM‐AgNCs was developed by estimating surface plasmon resonance peak around 449 nm by using a UV–Visible spectrophotometer. The effect of phytochemicals in SM leaf extract on the development of stable SM‐AgNCs was confirmed by FTIR spectroscopy. The size of the fabricated SM‐AgNCs was estimated by dynamic light scattering and zeta‐sizer analysis and the morphology of the SM‐AgNCs was examined by transmission electron microscopy. The presence of clusters of Ag particles in the prepared SM‐AgNCs was recognized by energy dispersion X‐ray analysis. The results show that saponins, phytosterols, and phenolic compounds present in plant extract may play a great part in developing the SM‐AgNCs in their specialized particles. The succeeded SM‐AgNCs shows incredible anti‐bacterial action towards Escherichia coli and Bacillus subtilis. In‐light of the antibacterial study, these SM‐AgNCs were analyzed with calf thymus‐DNA and found significant damage to the strand of thymus‐DNA. [ABSTRACT FROM AUTHOR]

Metallic nanoparticles can be synthesised in living plants, which provide a friendly approach. In this work, the authors aimed to study the synthesis of silver nanoparticles (AgNPs) in Arabidopsis and the two‐dimensional (2D) distribution of Ag and other elements (Ca, P, S, Mg, and CI) in the Arabidopsis plant tissues. The concentrations of Ag in the plant tissues were determined by inductively coupled plasma‐atomic emission spectrometer, showing that the majority of Ag was retained in the roots. Transmission electron micrographs showed the morphology of AgNPs and the location in plant cells. The distributions of Cl and Ag were consistent in plant tissues by 2D proton‐induced X‐ray emission. In conclusion, this is the first report of the AgNP synthesis in Arabidopsis living plants and its 2D distribution of important elements, which provide a new clue for further research. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) are toxic to various microbes, but the mechanism of action is not fully understood. The present report explores Azadirachta indica leaf extract as a reducing agent for the rapid biosynthesis of AgNPs. The effects of AgNPs on the growth, glutathione‐S‐transferase (GST) activity, and total protein concentration in Staphylococcus aureus were investigated, as was its antibacterial activity against seven other bacterial strains. Nanoparticle synthesis was confirmed by the UV‐Vis spectrum and colour change of the solution. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential analysis, and infrared spectroscopy were used to characterise the synthesised nanoparticles. The UV‐Visible spectrograph showed an absorbance peak at 420 nm. DLS analysis showed an average AgNP size of 159 nm and a Polydispersity Index of 0.373. SEM analysis showed spherical particle shapes, while TEM established an average AgNP size of 7.5 nm. The element analysis profile showed small peaks for calcium, potassium, zinc, chlorine, with the presence of oxygen and silver. AgNPs markedly affected the growth curves and GST activity in treated bacteria, and produced moderate antibacterial activity. Thus AgNPs synthesised from A. indica leaves can interrupt the growth curve and total protein concentration in bacterial cells. [ABSTRACT FROM AUTHOR]

The silver nanoparticles (AgNPs) with their unique chemical and physical properties are proving as a new therapeutical agent. In the present study, the AgNPs synthesised from an aqueous extract of a macrofungus, Earliella scabrosa, were characterised by field emission scanning electron microscopy (FESEM), energy dispersive X‐ray analysis (EDX), high‐resolution transmission electron microscopy, X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and further evaluate for its in vitro antibacterial and wound healing efficacy. The mycosynthesised AgNPs exhibited the surface plasmon resonance peak at 410 nm with good stability over a period of a month. The FESEM and EDX analyses revealed the spherical‐shaped AgNPs of an average size of 20 nm and the presence of elemental Ag, respectively. The XRD pattern showed the crystalline nature of AgNPs. The FTIR spectra confirmed the conversion of Ag+ ions to AgNPs due to reduction by biomolecules of macrofungus extract. The mycosynthesised AgNPs showed effective antibacterial activity against two Gram‐positive bacteria, namely Bacillus subtilis and Staphylococcus aureus, and two Gram‐negative bacteria Escherichia coli and Pseudomonas aeruginosa. The pathogens were highly sensitive to AgNPs, whereas less sensitive to AgNO3. The mycosynthesised AgNPs showed significant wound healing potential with 68.58% of wound closure. [ABSTRACT FROM AUTHOR]

In this study, the endogenous lipid signalling molecules, N ‐myristoylethanolamine, were explored as a capping agent to synthesise stable silver nanoparticles (AgNPs) and Ag sulphide NPs (Ag2 S NPs). Sulphidation of the AgNPs abolishes the surface plasmon resonance (SPR) maximum of AgNPs at 415 nm with concomitant changes in the SPR, indicating the formation of Ag2 S NPs. Transmission electron microscopy revealed that the AgNPs and Ag2 S NPs are spherical in shape with a size of 5–30 and 8–30 nm, respectively. AgNPs and Ag2 S NPs exhibit antimicrobial activity against Gram‐positive and Gram‐negative bacteria. The minimum inhibitory concentrations (MIC) of 25 and 50 μM for AgNPs and Ag2 S NPs, respectively, were determined from resazurin microtitre plate assay. At or above MIC, both AgNPs and Ag2 S NPs decrease the cell viability through the mechanism of membrane damage and generation of excess reactive oxygen species. [ABSTRACT FROM AUTHOR]

In this study, the authors synthesised silver nanoparticles (AgNPs) using autoclave as a simple, unique and eco‐friendly approach. The effect of Zingiber officinale extract was evaluated as a reducing and stabiliser agent. According to transmission electron microscopy results, the AgNPs were in the spherical shape with a particle size of ∼17 nm. The biomedical properties of AgNPs as antibacterial agents and free radical scavenging activity were estimated. Synthesised AgNPs showed significant 1,1‐diphenyl‐2‐picryl‐hydrazyl free radical scavenging. Strong bactericidal activity was shown by the AgNPs on Gram‐positive and Gram‐negative bacteria. A maximum inhibition zone of ∼14 mm was obtained for epidermidis at a concentration of 60 μg/ml for sample fabricated at 24 h. The AgNPs also showed a significant cytotoxic effect against MCF‐7 breast cancer cell lines with an half maximal inhibitory concentration value of 62 μg/ml in 24 h by the MTT assay. It could be concluded that Z. officinale extract can be used effectively in the production of potential antioxidant and antimicrobial AgNPs for commercial application. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have been biosynthesised through the extracts of Ribes khorassanicum fruits, which served as the reducing agents and capping agents. Biosynthesised AgNPs have been found to be ultraviolet–visible (UV–vis) absorption spectra since they have displayed one surface plasmon resonance peak at 438 nm, attesting the formation of spherical NPs. These particles have been characterised by UV–vis, field‐emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy analysis. The formation of AgNPs at 1.0 mM concentration of AgNO3 has resulted in NPs that contained mean diameters in a range of 20–40 nm. The green‐synthesised AgNPs have demonstrated high antibacterial effect against pathogenic bacteria (i.e. Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa). Biosynthesising metal NPs through plant extracts can serve as the facile and eco‐friendly alternative for chemical and/or physical methods that are utilised for large‐scale nanometal fabrication in various medical and industrial applications. [ABSTRACT FROM AUTHOR]

This work explores the rapid synthesis of silver nanoparticles (AgNPs) from Musa paradisiaca (M. paradisiaca) bract extract. The bio‐reduction of Ag+ ion was recorded using ultraviolet–visible spectroscopy by a surface plasmon resonance extinction peak with an absorbance at 420 nm. The phytoconstituents responsible for the reduction of AgNPs was probed using Fourier transform infrared spectroscopy. The X‐ray diffraction pattern confirmed the formation of crystalline AgNPs that were analogous to selected area electron diffraction patterns. Morphological studies showed that the obtained AgNPs were monodispersed with an average size of 15 nm. The biologically synthesised AgNPs showed higher obstruction against tested phytopathogens. The synthesised AgNPs exhibited higher inhibitory zone against fungal pathogen Alternaria alternata and bacterial pathogen Pseudomonas syringae. Free radical scavenging potential of AgNPs was investigated using 1,1‐diphenyl‐2‐picryl hydroxyl and 2,2‐azinobis (3‐ethylbenzothiazoline)‐6‐sulphonic acid assays which revealed that the synthesised AgNPs act as a potent radical scavenger. The catalytic efficiency of the synthesised AgNPs was investigated for azo dyes, methyl orange (MO), methylene blue (MB) and reduction of o‐nitrophenol to o‐aminophenol. The results portrayed that AgNPs act as an effective nanocatalyst to degrade MO to hydrazine derivatives, MB to leucomethylene blue, and o‐nitro phenol to o‐amino phenol [ABSTRACT FROM AUTHOR]

Multiple drug resistance and treatment of contaminated water has become a serious issue in past years. Silver nanoparticles (AgNPs), being bactericidal, non‐toxic, cheap and environment friendly behaviour, have drawn attention to overcome these problems. This study has been designed to synthesise AgNPs from Pseudomonas aeruginosa. AgNPs formation was confirmed by colour change and UV–vis spectroscopy. Furthermore, Fourier transform infrared spectroscopy peaks demonstrated the presence of capped proteins as reducing and stabilising agent. Transmission electron microscopy micrograph revealed spherical shape AgNPs with the size ranging between 10 and 20 nm. Antibacterial activity of AgNPs was evaluated against the most prevalent waterborne pathogens enterohaemorrhagic Escherichia coli and Salmonellae typhimurium. Moreover, the antibacterial activity of AgNPs was tested for the treatment of contaminated water which showed attenuation in bacterial load within 8 h as demonstrated by growth kinetics data. Furthermore, AgNPs did not exhibit haemolytic effects on human red blood cells (RBCs) even at 100 mg L−1 concentration of AgNPs. The results herein suggest that AgNPs synthesised by P. aeruginosa under optimised conditions exhibit microbicidal property against waterborne pathogens and having no toxic effect on human RBCs. These AgNPs could be employed for treatment of contaminated water after process optimisation. [ABSTRACT FROM AUTHOR]

Green synthesis of nanoparticles is considered an efficient method when compared with chemical and physical methods because of its bulk production, eco‐friendliness and low cost norms. The present study reports, for the first time, green synthesis of silver nanoparticles (AgNPs) at room temperature using Solanum viarum fruit extract. The visual appearance of brownish colour with an absorption band at 450 nm, as detected by ultraviolet‐visible spectrophotometer analysis, confirmed the formation of AgNPs. X‐ray diffraction confirmed the AgNPs to be crystalline with a face‐centred lattice. The transmission electron microscopy‐energy dispersive X‐ray spectroscopy image showed the AgNPs are poly‐dispersed and are mostly spherical and oval in shape with particle size ranging from 2 to 40 nm. Furthermore, Fourier transform‐infrared spectra of the synthesised AgNPs confirmed the presence of phytoconstituents as a capping agent. The antimicrobial activity study showed that the AgNPs exhibited high microbial activity against Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus susp. aureus, Aspergillus niger, and Candida albicans. The highest antimicrobial activity of AgNPs synthesised by S. viarum fruit extract was observed in P. aeruginosa, S. aureus susp. aureus and C. albicans with zone of inhibition, 26.67 mm. [ABSTRACT FROM AUTHOR]

Green synthesis of nanoparticles has fuelled the use of biomaterials to synthesise a variety of metallic nanoparticles. The current study investigates the use of xylanases of Aspergillus niger L3 (NEA) and Trichoderma longibrachiatum L2 (TEA) to synthesise silver nanoparticles (AgNPs). Characterisation of AgNPs was carried out using UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy, while their effectiveness as antimicrobial, antioxidant, catalytic, anticoagulant, and thrombolytic agents were determined. The colloidal AgNPs was brownish with surface plasmon resonance at 402.5 and 410 nm for NEA‐AgNPs and TEA‐AgNPs, respectively; while FTIR indicated that protein molecules were responsible for the capping and stabilisation of the nanoparticles. The spherical nanoparticles had size of 15.21–77.49 nm. The nanoparticles significantly inhibited the growth of tested bacteria (63.20–88.10%) and fungi (82.20–86.10%), and also scavenged DPPH (37.48–79.42%) and hydrogen peroxide (20.50–96.50%). In addition, the AgNPs degraded malachite green (78.97%) and methylene blue (25.30%). Furthermore, the AgNPs displayed excellent anticoagulant and thrombolytic activities using human blood. This study has demonstrated the potential of xylanases to synthesise AgNPs which is to the best of our knowledge the first record of such. The present study underscores the relevance of xylanases in nanobiotechnology. [ABSTRACT FROM AUTHOR]

The present work is emphasised on the bio‐fabrication of silver and gold nanoparticles in a single step by a microwave‐assisted method using the leaf extract of Synedrella nodiflora as both reducing and stabilising agent. The synthesised nanoparticles are highly stable and show surface plasmon resonance peak at 413 and 535 nm, respectively, for silver and gold nanoparticles in UV–Vis spectrum. The functional group responsible for the reduction of metal ions were obtained from Fourier transform infrared spectroscopy. The crystalline nature of nanoparticles with face‐centred cubic geometry was confirmed by the X‐ray diffraction and selected area electron diffraction patterns. The morphology and sizes of the silver and gold nanoparticles were obtained from transmission electron microscopy images. The nanoparticles exhibit effective antimicrobial activities against various pathogenic strains. These antimicrobial properties were analysed by employing agar well diffusion method. The nanoparticles show significant antioxidant properties, and it was determined using 2, 2‐diphenyl‐1‐picrylhydrazyl assay. The nanoparticles also show potent catalytic activity in the degradation of anthropogenic pollutant dyes Congo red and eosin Y by excess NaBH4. Thus, the current study demonstrates the potential use of S. nodiflora as a reducing and stabilising agent for the synthesis of silver and gold nanoparticles and their relevance in the field of biomedicine and catalysis. [ABSTRACT FROM AUTHOR]

Here, extracellular synthesis of silver nanoparticles (AgNPs) was carried out by Planococcus plakortidis strain BGCC‐51 isolated from dye industry effluent soil. The microbes were isolated, screened, and characterised by molecular analysis (accession number KX776160). The optimisation of synthesis of AgNPs to determine the optimum substrate level (1–5 mM), pH (5–9), and temperature (25–55°C) were further carried out. P. plakortidis strain BGCC‐51 gave best yield of AgNPs at substrate concentration 5 mM, pH 8, and at 35°C. Synthesised AgNPs were characterised by scanning electron microscope and high‐resolution transmission electron microscope. The size of synthesised AgNPs was in the range of 20–40 nm having spherical morphology. The AgNPs were found to show antimicrobial activity against bacteria such as Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), and Staphylococcus aureus (ATCC 29213). [ABSTRACT FROM AUTHOR]

The metal nanoparticles, due to interesting features such as electrical, optical, chemical and magnetic properties, have been investigated repeatedly. Also, the mentioned nanoparticles have specific uses in terms of their antibacterial activity. The biosynthesis method is more appropriate than the chemical method for producing the nanoparticles because it does not need any special facilities; it is also economically affordable. In the current study, the silver nanoparticles (AgNPs) were obtained by using a very simple and low‐cost method via Glaucium corniculatum (L.) Curtis plant extract. The characteristics of the AgNPs were investigated using techniques including: X‐ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy. The SEM and TEM images showed that the nanoparticles had a spherical shape, and the mean diameter of them was 53.7 and 45 nm, respectively. The results of the disc diffusion test used for measuring the anti‐bacterial activity of the synthesised nanoparticles indicated that the formed nanoparticles possessed a suitable anti‐bacterial activity. [ABSTRACT FROM AUTHOR]

In this study, the leaf extract of an important medicinal plant Crescentia cujete L. (CC) was employed as a green reducing agent to synthesise highly‐stable C. cujete silver nanoparticles (CCAgNPs). The reduction of Ag+ to Ag0 nanoparticles was initially observed by a colour change which generates an intense surface plasmon resonance peak at 417 nm using a UV‐Vis spectrophotometer. Various optimisation factors such as temperature, pH, time and the stoichiometric proportion of the reaction mixture were performed, which influence the size, dispersity and synthesis rate of CCAgNPs. In addition, surface chemistry of synthesised CCAgNPs through Fourier transform infrared spectroscopy reveals the reducing/stabilising agent present in the aqueous extract of C. cujete and synthesised CCAgNPs. Transmission electron microscopy analysis features the spherical shape of CCAgNPs with an average size of 39.74 nm. Furthermore, an X‐ray diffraction study confirms that the synthesised CCAgNPs were face‐centred cubic crystalline in nature. The CCAgNPs display tremendous bactericidal activity against human pathogens Bacillus subtilis, Staphylococcus epidermidis, Rhodococcus rhodochrous, Salmonella typhi, Mycobacterium smegmatis, Shigella flexneri and Vibrio cholerae via penetrating into the bacterial cell membrane and causing failure of an internal chain reaction. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (SNPs) were synthesised by using the Arial part extract of Dorema ammoniacum D. and characterised by employing UV–visible spectroscopy, Fourier transform infrared spectroscopy and X‐ray diffraction techniques. Transmission electron microscopy and field emission scanning electron microscopy were applied to investigate the morphological structure of the bio‐synthesised SNPs. The antimicrobial activity of SNPs was studied against Gram positive (Bacillus cereus and Staphylococcus aureus) and Gram‐negative (Escherichia coli and Salmonella typhimurium) bacteria by employing the disk diffusion agar process. An extremely antimicrobial effect was observed for SNPs. Utilising D. ammoniacum D. as a mediator for the synthesis of SNPs helped to save time and cost. [ABSTRACT FROM AUTHOR]

Green synthesis of silver nanoparticles (AgNPs) using Shivlingi (Bryonia laciniosa) seed extract was carried out. Characterisation of synthesised nanoparticles was accomplished through the optical absorption and photoluminescence spectrum, X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The XRD analysis further confirmed the size of nanoparticles ∼15 nm. TEM images revealed homogeneous spherical ∼10 nm Bryonia extract capped AgNPs. The biological studies indicated that both Bryonia seed extract and the nanoparticles lack anti‐microbial activity; however, the nanoparticles had better cytotoxicity and total antioxidant activity. The Lethal concentration (LC)50 value of water extract and the nanoparticles were found to be 1091 and 592 μg/ml, respectively. The lower LC50 of nanoparticles indicates that it is more cytotoxic than the crude extract. The results indicate that the Bryonia seed is safe to be used as a medicine and the formation of their nanoparticle has further enriched the chemical reactivity, energy absorption and biological mobility. [ABSTRACT FROM AUTHOR]

Fusarium wilt of tomato (Lycopersicon esculentum) caused by Fusarium oxysporum f. sp. lycopersici is one of the most important diseases that affect this crop worldwide. This study aimed to biosynthesise nanosilver (AgNPs) using Chaetomium globosum, to evaluate its in vitro antifungal activity against pathogenic F. oxysporum and in vivo control of tomato seedlings wilt in the greenhouse. AgNPs was tested for its in vitro antifungal potential against F. oxysporum using poisoned food technique on three different growth media, agar well diffusion assay, inhibition of colony formation (CFU), and tested for its potency to control seedlings wilt upon its use at different concentrations (50, 100 and 500 mg/l) and for different incubation periods (0, 1, 2 and 4 h). Results indicated that C. globosum succeeded to biosynthesise AgNPs with maximum UV/vis absorbance around 420–450 nm, spherical in shape with particle size of 11–14 nm according to Transmittance electron microscope and displayed high purity recorded through X‐ray diffraction (XRD). In vitro studies revealed high antifungal activity of AgNPs against F. oxysporum noticed especially at a concentration of 500 mg/l and after incubation period for 4 h. The CFU of F. oxysporum on potato dextrose agar (PDA) medium decreased significantly on increasing the concentration and time of incubation with AgNPs. In the greenhouse, AgNPs caused appreciable enhancement in the growth parameters of tomato seedlings such as; root, shoot fresh weight, and height of seedlings in soil infested with F. oxysporum compared with the control. In addition, AgNPs reduced the severity of wilt disease by 90% observed through decreasing the number of wilted seedlings especially after placing their roots in 500 mg/l of AgNPs suspension for 4 h prior to soil infestation with the pathogen. This study recorded for the first time that C. globosum has the ability to synthesise AgNPs which showed significant in vivo antifungal potential observed through control of Fusarium wilt of tomato seedlings, in addition to enhancing their growth parameters in the greenhouse. [ABSTRACT FROM AUTHOR]

Biological synthesis of nanomaterials is a growing innovative approach and it was broadly utilised in the field of nanotechnology and nanomedicine. This study illustrates that biosynthesis of silver nanoparticles (AgNPs) using fucoidan extracted from seaweed Padina tetrastromatica. The functional groups of extracted fucoidan were characterised by Fourier transform infrared spectroscopy (FTIR) and used to NPs synthesis. Synthesised AgNPs were characterised by ultraviolet–visible spectra, scanning electron microscope, energy dispersive X‐ray, transmission electron microscope, selected area electron diffraction and FTIR. In this study, their main focus is enhancement antibacterial activity of AgNPs coated antibiotics against antibiotic resistant bacteria. Among the microorganisms, Serratia nematodiphila was resistant to novobiocin and penicillin, but it was sensitive to AgNPs impregnated antibiotic discs. The zone of inhibition was 12 and 15 mm. The synergistic effect of combined antibiotics and AgNPs resulted in increased fold area which was greater than the sum of their separate effects. It reveals that AgNPs are highly sought in the medicinal field due to their broad spectrum of antibacterial activity and relatively cheaper. This enhanced synergistic effect potentially superior to control the growth of bacteria and it is the budding process for the development of new remedial agents for severe diseases. [ABSTRACT FROM AUTHOR]

The authors report extracellular mycosynthesis of silver nanoparticles (AgNPs) by Phoma capsulatum, Phoma putaminum and Phoma citri. The AgNPs thus synthesised were characterised by UV–visible spectrophotometer, Fourier transform infrared spectroscopy, Nanosight LM20 and transmission electron microscopy, which confirmed the synthesis of mostly spherical and polydisperse nanoparticles capped with proteins. The size of AgNPs was found in the range of 10–80, 5–80 and 5–90 nm with an average size of 31.85, 25.43 and 23.29 nm by P. capsulatum, P. putaminum and P. citri, respectively. Further, potential antimicrobial activity was reported against Aspergillus niger, Candida albicans, Salmonella choleraesuis, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. The lowest minimal inhibitory concentration (MIC) (0.85 µg/ml) was reported for AgNPs synthesised from P. citri against S. choleraesuis. However, AgNPs synthesised from P. capsulatum showed the highest MIC (10.62 µg/ml) against S. choleraesuis, P. aeruginosa and E. coli (clinical isolate). The same MIC values (10.62 µg/ml) were also reported against P. aeruginosa and both clinical and standard isolates of E. coli for AgNPs synthesised from P. citri. It was also observed that all the silver nanoparticles showed remarkable antifungal and antibacterial activity against these tested pathogens as compared with the commercially available antifungal and antibacterial agents. [ABSTRACT FROM AUTHOR]

This study focuses on the green synthesis of noble metal nanoparticles (silver (Ag) and platinum (Pt)) and how the size and shape of the nanoparticles produced can be controlled through changes in the initial pH value of the precursor solution. The nanoparticles were characterised by ultra‐violet‐visible spectroscopy, transmission electron microscopy and X‐ray diffraction. This simple and environmentally friendly method allows the synthesis of diverse nanostructures in the absence of a surfactant or polymer to direct nanoparticle growth, and without externally adding seed crystallites. The antibacterial effects of Ag nanoparticles and catalytic properties of Pt nanoparticles were explored for future promising biotechnological approaches in different fields. [ABSTRACT FROM AUTHOR]

The authors report the biological synthesis of silver nanoparticles (NPs) by Phoma gardeniae (ITCC 4554). The detection of silver NP formation was done by visual observation, and UV–vis spectrophotometer analysis. Further, these mycogenic silver NPs were characterised by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and nanoparticle tracking and analysis system. The TEM analysis revealed the formation of spherical and polydispersed NPs within the range of 10–30 nm. FTIR analysis confirmed the presence of proteins as capping agents. They also evaluated the antimicrobial activity of silver NPs against Candida albicans, Salmonella choleraesuis, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. They found remarkable inhibition of Escherichia coli followed by Staphylococcus aureus, Candida albicans, Salmonella choleraesuis and Pseudomonas aeruginosa as compared with antibiotics. The main aim of the present study was to synthesise mycogenic silver NPs by P. gardeniae and to evaluate their antimicrobial activity in order to find their potential against human pathogenic microbes. [ABSTRACT FROM AUTHOR]

Lawsonia inermis mediated synthesis of silver nanoparticles (Ag‐NPs) and its efficacy against Candida albicans, Microsporum canis, Propioniabacterium acne and Trichophyton mentagrophytes is reported. A two‐step mechanism has been proposed for bioreduction and formation of an intermediate complex leading to the synthesis of capped nanoparticles was developed. In addition, antimicrobial gel for M. canis and T. mentagrophytes was also formulated. Ag‐NPs were synthesized by challenging the leaft extract of L. inermis with 1 mM AgNO3. The Ag‐NPs were characterized by Ultraviolet‐Visible (UV–Vis) spectrophotometer and Fourier transform infrared spectroscopy (FTIR). Transmission electron microscopy (TEM), nanoparticle tracking and analysis sytem (NTA) and zeta potential was measured to detect the size of Ag‐NPs. The antimicrobial activity of Ag‐NPs was evaluated by disc diffusion method against the test organisms. Thus these Ag‐NPs may prove as a better candidate drug due to their biogenic nature. Moreover, Ag‐NPs may be an answer to the drug‐resistant microorganisms. [ABSTRACT FROM AUTHOR]