Silver nanoparticles from Prosopis glandulosa and their potential application as biocontrol of Acinetobacter calcoaceticus and Bacillus cereus

In the present study the characterization and properties of silver nanoparticles from Prosopis glandulosa leaf extract (AgNPs) were investigated using UV–Vis spectroscopic techniques, energy dispersive X-ray spectrometers (EDS), zeta potential and dynamic light scattering. The UV–Vis spectroscopic analysis showed the absorbance peaked at 487 nm, which indicated the synthesis of silver nanoparticles. The experimental results showed silver nanoparticles had Z-average diameter of 421 nm with higher stability (?200 mV). The EDS analysis also exhibited presentation of silver element. Additionally, the different concentrations of AgNPs (25, 50, 75 and 100 mg/mL) showed antibacterial activity against Acinetobacter calcoaceticus and Bacillus cereus. Finally, AgNPs from leaf extracts of P. glandulosa may be used as an agent of biocontrol of microorganism of importance medical. However, further studies will be needed to fully understand the antimicrobial activity of silver nanoparticles obtain from P. glandulosa.     

Synthesis of silver nanoparticles using plant derived 4-N-methyl benzoic acid and evaluation of antimicrobial,antioxidant and antitumor activity

The present study is to investigate the antitumor, antioxidant and antibacterial potential of silver nanoparticles (Ag NPs) synthesized from a phenolic derivative 4-N-methyl benzoic acid, isolated from a medicinal plant (Memecylon umbellatum Burm F). The Bio-inspired nanoparticles (NPs) were analyzed by using UV–vis spectroscopy, FTIR, HRTEM, Zeta potential and XRD techniques. The UV–vis spectroscopy study at the band of 430 nm confirmed the nanoparticles formation. HRTEM report showed that the AgNPs synthesized were in the size range 7–23 nm. The harvested nanoparticles were subjected to anti-bacterial assay and a dose dependent inhibitory action was observed against the tested human pathogens. Among the tested bacteria, Acinetobacter baumannii was found to be highly sensitive to AgNPs (diameter of zone of inhibition was 31 mm). Further, the silver nanoparticles exhibited a good anti-tumor activity against the breast cancer cell line (MCF 7) with an IC₅₀ value of 42.19 µg/mL. As the present study confirmed a good antibacterial, antioxidant and antitumor activity in the nanoparticles synthesized using 4-N-methyl benzoic acid derived from a medicinal plant, the product can be further tested to formulate a good lead compound for biomedical applications.     

Silver nanoparticles biosynthesized from secondary metabolite producing marine actinobacteria and evaluation of their biomedical potential

Biosynthesis of silver nanoparticles (AgNPs) from marine actinobacteria offers a promising avenue for exploring bacterial extracts as reducing and stabilizing agents. We report extracellular extracts of Rhodococcus rhodochrous (MOSEL-ME29) and Streptomyces sp. (MOSEL-ME28), identified by 16S rRNA gene sequencing for synthesis of AgNPs. Ultrafine silver nanoparticles were biosynthesized using the extracts of R. rhodochrous and Streptomyces sp. and their possible therapeutic applications were studied. The physicochemical properties of nanoparticles were established by HR-SEM/TEM, SAED, UV–Vis, EDS, XRD, and FTIR. UV–Vis spectra displayed characteristic absorption at 430 nm and 412 nm for AgNPs from Streptomyces sp. (S-AgNPs) and Rhodococcus sp. (R-AgNPs), respectively. HR-SEM/TEM, XRD, EDS analysis confirmed the spherical shape, crystalline nature, and elemental formation of silver. Crystallite or grain size was deduced as 5.52 nm for R-AgNPs and 35 nm for S-AgNPs. Zeta-potential indicated electrostatic negative charge for AgNPs, while FTIR revealed the presence of diverse functional groups. Disc diffusion assay indicated the broad-spectrum antibacterial potential of S-AgNPs with the maximum inhibition of B. subtilis while R-AgNPs revealed potency against P. aeruginosa at 10 µg/mL concentration. Biogenic AgNPs revealed antileishmanial activity and the IC₅₀ was calculated as 164 µg/mL and 184 µg/mL for R-AgNPs and S-AgNPs respectively. Similarly, the R-AgNPs and S-AgNPs revealed anti-cancer potential against HepG2 and the IC₅₀ was calculated as 49 µg/mL and 69 µg/mL for R-AgNPs and S-AgNPs, respectively. Moreover, the antioxidant activity showed significant results. MTT assay on RD cells, L20B cells, and Hep-2C indicated intensification in viability by reducing the concentration of R-AgNPs and S-AgNPs. The R-AgNPs and S-AgNPs inhibited sabin-like poliovirus (1TCID₅₀ infection in RD cells). Furthermore, hemocompatibility at low concentrations has been confirmed. Hence, it is concluded that biogenic-AgNPs has the potential to be used in diverse biological applications and that the marine actinobacteria are an excellent resource for fabrication of AgNPs.

     

Pharmacological properties of biogenically synthesized silver nanoparticles using endophyte Bacillus cereus extract of Berberis lyceum against oxidative stress and pathogenic multidrug-resistant bacteria

The emergence of multidrug resistance in pathogenic bacteria limits the utilization of available antibiotics. The development of alternate options to treat infectious diseases is the need of the day.The present study was aimed to synthesize, characterize and evaluate the bioactive properties of silver nanoparticles. Endophytic bacterium Bacillus cereus (MT193718) isolated from Berberis lycium was used to synthesize biocompatible silver nanoparticles. Antibacterial properties of AgNPs were evaluated against clinically isolated multidrug-resistant strains of Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae. AgNPs indicated significant antibacterial activity against S. aureus and K. pneumoniae fwith a zone of inhibition of 17 and 18 mm at a concentration of 1000 µg/ mL with minimum inhibitory concentration of 15.6 and 62.5 µg/mL respectively. Significant antioxidant activity with an IC50 value of 9.5 µg/mL was recorded. Biosynthesized AgNPs were found compatible with red blood cells at a concentration of 31.5 µg/ml with no clumping of erythrocytes. The study suggested that AgNPs synthesized by the endophytic bacterium Bacillus cereus are biologically active and can be used as antioxidant and antibacterial agents against drug-resistant bacteria.     

Antioxidant,antibacterial and cytotoxic potential of silver nanoparticles synthesized using terpenes rich extract of Lantana camara L. leaves

Several attempts have been made for green synthesis of silver nanoparticles (AgNPs) using different plant extracts. Present study revealed that, antioxidant, antibacterial and cytotoxic AgNPs were synthesized using terpenes-rich extract (TRE) of environmentally notorious Lantana camara L. leaves. AgNPs were characterized by advanced techniques like UV–Visible and Infra red spectroscopy; XRD, SEM techniques as terpenes coated sphere shaped NPs with average diameter 425 nm. Further, on evaluation, AgNPs were found to exhibit dose – dependent antioxidant potential, good to moderate antibacterial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa; and toxicity on Brine shrimp (A. salinanauplii) with LD₅₀ value 514.50 µg/ml.     

Polyphenolic extracts from pomegranate and watermelon wastes as substrate to fabricate sustainable silver nanoparticles with larvicidal effect against Spodoptera littoralis

The agricultural wastes adversely affect the environment; however, they are rich in polyphenols; therefore, this study aimed to employ polyphenol-enriched waste extracts for silver nanoparticles synthesis, and study the larvicidal activity of silver nanoparticles fabricated by pomegranate and watermelon peels extracts (PPAgNPs and WPAgNPs) against all larval instars of Spodoptera littoralis. The polyphenol profile of pomegranate and watermelon peel extracts (PP and WP) and silver nanoparticles was detected by HPLC. The antioxidant activity was estimated by DPPH, and FARP assays and the antimicrobial activity was evaluated by disc assay. The Larvicidal activity of AgNPs against Egyptian leaf worm was performed by dipping technique. The obtained AgNPs were spherical with size ranged 15–85 nm and capped with proteins and polyphenols. The phenolic compounds in silver nanoparticles increased about extracts; therefore, they have the best performance in antioxidant/reducing activity, and inhibit the growth of tested bacteria and yeast. The PPAgNPs were the most effective against the first instar larvae instar (LC₅₀ = 68.32 µg/ml), followed by pomegranate extract with (LC₅₀ = 2852 µg/ml). The results indicated that obvious increase in polyphenols content in silver nanoparticles enhance their larvicidal effect and increasing mortality of 1^st larval of S. littoralis Egyptian leafworms causing additive effect and synergism. We recommend recycling phenolic enriched agricultural wastes in producing green silver nanoprticles to control cotton leafworm that causes economic loses to crops.     

Biosynthesis,characterization and antimicrobial activity of silver nanoparticles by a halotolerant Bacillus endophyticus SCU-L

Abstract

We have conducted a thorough study on extracellular biosynthesis of silver nanoparticles (AgNPs) by a halotolerant bacterium Bacillus endophyticus SCU-L, which was identified by 16S rRNA gene sequencing analysis. This strain was selected during an ongoing research programme aimed at finding a novel biological method for green nanosynthetic routes using the extremophiles in unexplored hypersaline habitats. The biosynthesized AgNPs were characterized and analyzed with UV–vis spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, atomic force microscopy and X-ray diffraction. Further, the AgNPs were found to be spherical in shape with an average particle size of about 5.1?nm, and it was stable in aqueous solution for three months period of storage at room temperature under dark condition. Also, the synthesized AgNPs significantly presented antimicrobial activity against Candida albicans, Escherichia coli, Salmonella typhi and Staphylococcus aureus. The above results suggested that the present work may provide a valuable reference and theoretical basis for further exploration on microbial biosynthesis of AgNPs by halotolerant bacteria.     

Characterization,antimicrobial, antioxidant,and anticoagulant activities of silver nanoparticles synthesized from Petiveria alliacea L. leaf extract

Abstract

Phytosynthesis of silver nanoparticles (AgNPs) using leaf extract of Petiveria alliacea (PA) was the focus of this research work. The PA-AgNPs were characterized by UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) study. Studies were made on the AgNPs for antibacterial, antifungal, anticoagulant, free-radical scavenging, and hydrogen peroxide scavenging activities. The crystalline PA-AgNPs were monodispersed, with a size range of 16.70–33.74?nm and maximum absorption at 410?nm. FTIR analysis displayed prominent peaks at 3430.6, 1711.8, and 1165.9/cm, which showed the existence of phenolic compounds and proteins in the synthesis of AgNPs. PA-AgNPs was active against Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus, with 100% inhibition. The PA-AgNPs also displayed good antifungal properties, as the concentrations of 100 and 150?µg/mL had 100% inhibition toward Aspergillus fumigatus and Aspergillus flavus. However, there was 66.67% inhibition of Aspergillus niger. It scavenged both DPPH and H₂O₂ by 70.69 and 89.02%, respectively. PA-AgNPs also prevented the coagulation of human blood. This study, being the first of its kind to use the leaf extract of PA for the synthesis of AgNPs has shown that PA-AgNPs can find biomedical applications.     

Antibacterial activity of silver nanoparticle-coated fabric and leather against odor and skin infection causing bacteria

We present a simple, eco-friendly synthesis of silver and gold nanoparticles using a natural polymer pine gum solution as the reducing and capping agent. The pine gum solution was combined with silver nitrate (AgNO₃) or a chloroauric acid (HAuCl₄) solution to produce silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs), respectively. The reaction process was simple; formation of the nanoparticles was achieved by autoclaving the silver and gold ions with the pine gum. UV–Vis spectra showed surface plasmon resonance (SPR) for silver and gold nanoparticles at 432 and 539 nm, respectively. The elemental forms of AgNPs and AuNPs were confirmed by energy-dispersive X-ray spectroscopy (EDX). Fourier transform infrared spectroscopy (FTIR) showed the biomolecules present in the pine gum, AgNPs, and AuNPs. Transmission electron microscopy (TEM) images showed the shape and size of AgNPs and AuNPs. The crystalline nature of synthesized AgNPs and AuNPs was confirmed by X-ray crystallography [X-ray diffraction (XRD)]. Application of synthesized AgNPs onto cotton fabrics and leather, in order to evaluate their antibacterial properties against odor- or skin infection-causing bacteria, is also discussed. Among the four tested bacteria, AgNP-coated cotton fabric and leather samples displayed excellent antibacterial activity against Brevibacterium linens.     

Synthesis,characterization and evaluation of antimicrobial and cytotoxic activities of biogenic silver nanoparticles synthesized from <Emphasis Type="Italic">Streptomyces xinghaiensis</Emphasis> OF1 strain

We report synthesis of silver nanoparticles (AgNPs) from Streptomyces xinghaiensis OF1 strain, which were characterised by UV–Vis and Fourier transform infrared spectroscopy, Zeta sizer, Nano tracking analyser, and Transmission electron microscopy. The antimicrobial activity of AgNPs alone, and in combination with antibiotics was evaluated against bacteria, namely Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis, and yeasts viz., Candida albicans and Malassezia furfur by using micro-dilution method. The minimum inhibitory concentration (MIC) and minimum biocidal concentration of AgNPs against bacterial and yeast strains were determined. Synergistic effect of AgNPs in combination with antibacterial and antifungal antibiotics was determined by FIC index. In addition, MTT assay was performed to study cytotoxicity of AgNPs alone and in combination with antibiotics against mouse fibroblasts and HeLa cell line. Biogenic AgNPs were stable, spherical, small, polydispersed and capped with organic compounds. The variable antimicrobial activity of AgNPs was observed against tested bacteria and yeasts. The lowest MIC (16 µg ml^?1) of AgNPs was found against P. aeruginosa, followed by C. albicans and M. furfur (both 32 µg ml^?1), B. subtilis and E. coli (both 64 µg ml^?1), and then S. aureus and Klebsiella pneumoniae (256 µg ml^?1). The high synergistic effect of antibiotics in combination with AgNPs against tested strains was found. The in vitro cytotoxicity of AgNPs against mouse fibroblasts and cancer HeLa cell lines revealed a dose dependent potential. The IC₅₀ value of AgNPs was found in concentrations of 4 and 3.8 µg ml^?1, respectively. Combination of AgNPs and antibiotics significantly decreased concentrations of both antimicrobials used and retained their high antibacterial and antifungal activity. The synthesis of AgNPs using S. xinghaiensis OF1 strain is an eco-friendly, cheap and nontoxic method. The antimicrobial activity of AgNPs could result from their small size. Remarkable synergistic effect of antibiotics and AgNPs offer their valuable potential in nanomedicine for clinical application as a combined therapy in the future.     

Synthesis of Ag-liposome nano composites

Silver nanoparticles were synthesized and stabilized by a simple, environment-friendly method in a liposomes structure. Liposomes were prepared by facing lecithin to the aqueous-phase solutions while stirring vigorously. The ratio of lecithin concentration to silver nitrate (K_Lec/Ag?=?[Lecithin]/[AgNO₃]) is the influencing factor in the synthesis of silver nanoparticles. The stability, size distribution, and antibacterial properties of synthesized silver nanoparticles were studied by ultraviolet (UV)-visible, dynamic light scattering, and antibacterial assay. The UV spectra indicated a single symmetric extinction peak at 400?nm, confirming the spherical shape of the synthesized silver nanoparticles. A high K_Lec/Ag value leads to a reduction in the intensity of extinction spectra and increases the size of Ag-liposomes nanocomposites. The large Ag-liposomes nanocomposites are transformed to the smaller Ag-liposomes nanocomposites (from 342 to 190?nm) due to sonication treatment. The stabilized silver nanoparticles with various lecithin concentrations showed a good antibacterial activity against Staphylococcus aureus, a Gram-positive bacterium, and Escherichia coli, a Gram-negative bacterium.     

Prospective of biosynthesized L.satiVum oil/PEG/Ag-MgO bionanocomposite film for its antibacterial and anticancer potential

A substantial interest has been manifested in utilizing oil/metal oxide hybrid bionanocomposite, especially organic/ inorganic to design different biomedical applications. The present study reports the synthesis, characterization, antibacterial and anticancer properties of biogenic silver nanoparticles (AgNPs) and L.satiVum oil/PEG/Ag-MgO bionanocomposite. The fabricated AgNPs and L.sativum oil/PEG/Ag-MgO bionanocomposite were characterized by employing different spectroscopic (UV, FTIR, XRD) and microscopic (TEM, SEM) techniques. The particle size analysis showed that the mean size of 16.32 nm for AgNPS and 13.45 nm L.satiVum oil/PEG/Ag-MgO, indicating the excellent dispersion of Ag-MgO nanoparticles in the PEG– L.satiVum oil matrix. The antimicrobial activity of AgNPs and polymeric bionanocomposite was investigated against two pathogenic bacteria. The highest antibacterial effect was observed for bionanocomposite towards Gram-positive Staphylococcus aureus (27 mm) and Gram-negative Escherichia coli (25 mm) at 40 µg/well. The bionanocomposite completely vanished the bacterial growth (100%) at 80 µgmL⁻¹ concentrations. Moreover, the AgNPs and polymeric bionanocomposite was evaluated for anticancer activity against human cervical cancer cells (HeLa cells) at different doses (50, 250, 500, and 1000 µgmL⁻¹). The results showed polymeric bionanocomposite was stronger in inducing the HeLa cancer cell death than AgNPs. Overall, the fabricated L.satiVum oil/PEG/Ag-MgO bionanocomposite serve as a potential antimicrobial and anticancer agent and could be used in the development of novel drugs and health care products in near future.     

Prolonged inhibitory effects against planktonic growth,adherence, and biofilm formation of pathogens causing ventilator-associated pneumonia using a novel polyamide/silver nanoparticle composite-coated endotracheal tube

Abstract

Microbial cells can rapidly form biofilm on endotracheal tubes (ETT) causing ventilator-associated pneumonia, a serious complication in patients receiving mechanical ventilation. A novel polyamide with a good balance of hydrophilic/hydrophobic moieties was used for the embedment of green-reduction silver nanoparticles (AgNPs) for the composite-coated ETT. The films were conformal with a thickness of ～ 17?±?3?µm accommodating high loading of 60?±?35?nm spherical-shaped AgNPs. The coated ETT resulted in a significant difference in reducing both planktonic growth and microbial adhesion of single and mixed-species cultures, compared with uncoated ETT (p?<?0.05). A time-kill assay demonstrated rapid bactericidal effects of the coating on bacterial growth and cell adhesion to ETT surface. Biofilm formation by Pseudomonas aeruginosa and Staphylococcus aureus, commonly encountered pathogens, was inhibited by > 96% after incubation for 72?h. Polyamide/AgNP composite-coated ETT provided a broad-spectrum activity against both Gram-positive and Gram-negative bacteria as well as Candida albicans and prolonged antimicrobial activity.     

Fruit extract capped colloidal silver nanoparticles and their application in reduction of methylene blue dye

Green synthesis of silver nanoparticles (AgNPs) has become a promising environmentally benign synthetic route in nanoscience and nanotechnology during recent years. In the present work, we have developed an environment-friendly and low-cost method for synthesis of silver nanoparticles from silver nitrate using aqueous fruit extract of Dillenia indica. The as-synthesized nanoparticles were characterized by UV-Vis spectrophotometer, transmission electron microscopy (TEM) and X-ray diffraction (XRD). FTIR study was performed to know the interaction of bio-molecules present in the fruit extract with AgNPs. The catalytic application of the as-synthesized AgNPs was demonstrated against degradation of methylene blue (MB) in aqueous system. The absorption spectra of colloidal suspension of AgNPs showed characteristic surface plasmon resonance (SPR) band centred at a wavelength of 416?nm. TEM image showed that the AgNPs were almost spherical in shape having an average diameter of 10.78?±?.48?nm. XRD pattern and selected area electron diffraction (SAED) pattern with bright spots signify the crystalline nature of nanoparticles. The fruit extract-capped AgNPs was highly stable and have showed the effective catalytic activity in reduction of MB dye.     

Green synthesis of silver nanoparticles with Dalbergia spinosa leaves and their applications in biological and catalytic activities

The phytosynthesis of silver nanoparticles (AgNPs) by Dalbergia spinosa leaves (DSL) in aqueous extract was investigated. AgNPs were characterized by UV–visible absorption spectroscopy (UV–vis), transmission electron microscopy (TEM) and Fourier transform infra red spectrophotometry (FTIR). The results showed that the increase in the initial extract concentration at room temperature increased the mean size and widened the size distribution of the AgNPs, leading to a red shift and broadening the surface plasmon resonance absorption (439 nm). The results showed that the reducing sugars and flavonoids were primarily responsible for the bioreduction of silver ions and that their reductive capability was promoted at 36 °C. TEM analysis showed that the AgNPs were nearly spherical in shape with an average size of 18 ± 4 nm. When evaluated for in vitro antioxidant activity by DPPH, NO, hydrogen peroxide radicals, reducing power and CUPRAC assay methods in addition to anti-inflammatory activity by HBRC method, the silver nanoparticles exhibited considerably enhanced antioxidant and anti-inflammatory activity at the test doses when compared with that of the standards and the plant extract. Finally, the antibacterial activity of the AgNPs against two Gram-positive bacteria and two Gram-negative bacteria showed moderate antibacterial activity when compared with the standard and the plant extract. The synthesized silver nanoparticles were also effective in the catalytic reduction of 4-nitrophenol (4-NP) into 4-aminophenol (4-AP).     

Discrete Nanoparticles of Ruta Graveolens Induces the Bacterial and Fungal Biofilm Inhibition

Abstract

Ruta graveolens silver nanoparticles (AgNPs) showed the color change within 30 min and characterized using UV–visible spectra, Fourier Transform Infrared (FTIR), X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). UV–visible spectrum of R. graveolens AgNPs showed the sharp peak at the wavelength of 440–560 nm. XRD patterns confirmed that crystalline nature of R. graveolens AgNPs and FTIR results revealed that phytochemical reaction of these R. graveolens is responsible for the synthesis of AgNPs. TEM results showed the size of the R. graveolens AgNPs around 30–50 nm with spherical and triangular nature. Further, the antibacterial and antibiofilm activity of R. graveolens AgNPs showed the effective inhibitory activity against clinically important Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Our findings suggest that R. graveolens AgNPs can be exploited toward the development of potential antibacterial agents for various biomedical and environmental applications.     

Biogenic synthesis of silver nanoparticles: Antibacterial and cytotoxic potential

In green chemistry, the application of a biogenic material as a mediator in nanoparticles formation is an innovative nanotechnology. Our current investigation aimed at testing the cytotoxic potential and antimicrobial ability of silver nanoparticles (AgNPs) that were prepared using Calligonum comosum roots and Azadirachta indica leaf extracts as stabilizing and reducing agents. An agar well diffusion technique was employed to detect synthesized AgNPs antibacterial ability on Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus bacterial strains. Furthermore, their cytotoxic capability against LoVo, MDA-MB231 and HepG2 ca cells was investigated. For phyto-chemical detection in the biogenic AgNPs the Fourier-transform infrared spectroscopy (FT-IR) was considered. Zeta sizer, TEM (Transmission Electron Microscope) and FE-SEM (Field Emission Scanning Electron Microscope) were used to detect biogenic AgNPs’ size and morphology. The current results showed the capability of tested plant extract for conversion of Ag ions to AgNPs with a mean size ranging between 90.8 ± 0.8 and 183.2 ± 0.7 nm in diameter. Furthermore, prepared AgNPs exhibited apoptotic potential against HepG2, LoVo, and MDA-MB 231cell with IC₅₀ ranging between 10.9 and 21.4 μg/ml and antibacterial ability in the range of 16.0 ± 0.1 to 22.0 ± 1.8 mm diameter. Activation of caspases in AgNPs treated cells could be the main indicator for their positive effect causing apoptosis. The current investigation suggested that the green production of AgNPs could be a suitable substitute to large-scale production of AgNPs, since stable and active nanoparticles could be obtained.     

Efficacy of encapsulated biogenic silver nanoparticles and its disease resistance against Vibrio harveyi through oral administration in Macrobrachium rosenbergii

Biological synthesis of silver nanoparticles (AgNPs) by Cheatomorpha antennia and its in vitro and in vivo antibacterial activity against Vibrio harveyi in Macrobrachium rosenbergii was demonstrated in the study. In vitro growth curve analysis, cell viability and bacterial inhibitory assays were performed to test the efficacy of synthesised AgNPs against bacteria. Sodium caseinate was used as an encapsulating agent to deliver the antibacterial drugs and the commercial process of microencapsulation comprises the antibacterial bioelements for oral administration to improve the disease resistance of AgNPs against V. harveyi due to the eco-friendly for non-toxic behaviour of nanoparticle and their treatment. Characterisation of antibacterial silver was performed by UV spectroscopy, X-ray diffraction, Fourier Transform Infrared spectroscopy and Scanning Electron Microscopy. The peak at 420 nm showed the presence of nanoparticles in the solution and the crystal nature of the particle was identified by the XRD. FTIR characterised the functional harveyi biomolecules and further SEM confirmed the size of the nanoparticles around 24 ± 2.4 nm. Experimental pathogenicity of V. harveyi showed 100% mortality at the 120th hour. Treatment of encapsulated AgNPs was administered orally for the relative percentage of survival which acquired almost 90% of survival till 30 days of exposure. In conclusion, the microencapsulation of AgNPs in the biopolymer matrices promotes the health, growth responses, immunity and disease resistance of encapsulated AgNPs with an improved relative percentage of survival.     

Ultrasound assisted green synthesis of silver nanoparticles using weed plant

This study presents the facile, green and eco-friendly synthesis of silver nanoparticles (AgNPs) using weed plant Lantana camara L. leaf extract. The incorporation of ultrasound into this reduced the time and increased the reaction rate. The results showed that the AgNPs were spherical in shape with the average size of 33.8 nm. The EDAX pattern indicated the presence of abundant silver and XRD indicated that the (111) crystallographic plane more predominant than other planes. The possible functional groups responsible for the reduction and stabilization of AgNPs were identified using Fourier transform infrared spectroscope. The XPS results concluded that the nanoparticles were presented in its reduced metallic state. The antioxidant activity of AgNPs was assayed using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) test. The increase in the concentration of AgNPs increased the DPPH scavenging activity. The AgNPs revealed superior antibacterial activity against Gram positive and Gram negative organisms.