Biosynthesis Of Selenium Nanoparticles Research Articles

In vitro assessment of the effect of magnetic fields on efficacy of biosynthesized selenium nanoparticles by Alborzia kermanshahica

Cyanobacteria represent a rich resource of a wide array of unique bioactive compounds that are proving to be potent sources of anticancer drugs. Selenium nanoparticles (SeNPs) have shown an increasing potential as major therapeutic platforms and led to the production of higher levels of ROS that can present desirable anticancer properties. Chitosan–SeNPs have also presented antitumor properties against hepatic cancer cell lines, especially the Cht-NP (Chitosan–NPs), promoting ROS generation and mitochondria dysfunction. It is proposed that magnetic fields can add new dimensions to nanoparticle applications. Hence, in this study, the biosynthesis of SeNPs using Alborzia kermanshahica and chitosan (CS) as stabilizers has been developed. The SeNPs synthesis was performed at different cyanobacterial cultivation conditions, including control (without magnetic field) and magnetic fields of 30 mT and 60 mT. The SeNPs were characterized by uv-visible spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), Dynamic light scattering (DLS), zeta potential, and TEM. In addition, the antibacterial activity, inhibition of bacterial growth, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC), as well as the antifungal activity and cytotoxicity of SeNPs, were performed. The results of uv-visible spectrometry, DLS, and zeta potential showed that 60 mT had the highest value regarding the adsorption, size, and stabilization in compared to the control. FTIR spectroscopy results showed consistent spectra, but the increased intensity of peaks indicates an increase in bond number after exposure to 30 mT and 60 mT. The results of the antibacterial activity and the inhibition zone diameter of synthesized nanoparticles showed that Staphylococcus aureus was more sensitive to nanoparticles produced under 60 mT. Se-NPs produced by Alborzia kermanshahica cultured under a 60 mT magnetic field exhibit potent antimicrobial and anticancer properties, making them a promising natural agent for use in the pharmaceutical and biomedical industries.

Characterizations of biogenic selenium nanoparticles and their anti-biofilm potential against Streptococcus mutans ATCC 25175

IntroductionS. mutans has been identified as the primary pathogenic bacterium in biofilm-mediated dental caries. The biogenic selenium nanoparticles (SeNPs) produced by L. plantarum KNF-5 were used in this study against S. mutans ATCC 25175. ObjectivesThe aims of this study were: (1) the biosynthesis of SeNPs by L. plantarum KNF-5, (2) the characterization of SeNPs, (3) the investigation of the inhibitory effect of biogenic SeNPs against S. mutans ATCC 25175, and (4) the determination of the anti-biofilm potential of SeNPS against S. mutans ATCC 25175. Methodology3 mL of the culture was added to 100 mL of MRS medium and incubated. After 4 h, Na2SeO3 solution (concentration 100 μg/mL) was added and incubated at 37 °C for 36 h. The color of the culture solution changed from brownish-yellow to reddish, indicating the formation of SeNPs. The characterization of SeNPs was confirmed by UV-Vis spectrophotometry, FTIR, SEM-EDS and a particle size analyzer. The antibacterial activity was determined by the disk diffusion method, the MIC by the micro-double dilution method, and the biofilm inhibitory potential by the crystal violet method and the MTT assay. The effect of SeNPs on S. mutans ATCC 25175 was determined using SEM and CLSM spectrometry techniques. The sulfate-anthrone method was used to analyze the effect of SeNPs on insoluble extracellular polysaccharides. The expression of genes in S. mutans ATCC 25175 was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR). Preparation of nanoparticlesSeNPs produced by probiotic bacteria are considered a safe method. In this study, L. plantarum KNF-5 (probiotic strain) was used for the production of SeNPs. ResultsThe biogenic SeNPs were spherical and coated with proteins and polysaccharides and had a diameter of about 270 nm. The MIC of the SeNPs against S. mutans ATCC 25175 was 3.125 mg/mL. Biofilm growth was also significantly suppressed at this concentration. The expression of genes responsible for biofilm formation (GtfB, GtfC, BrpA and GbpB,) was reduced when S. mutans ATCC 25175 was treated with SeNPs. ConclusionIt was concluded that the biogenic SeNPs produced by L. plantarum KNF-5 was highly effective to inhibit the growth of S. mutans ATCC 25175. Novelty statementThe application of biogenic SeNPs, a natural anti-biofilm agent against S. mutans ATCC 25175. In the future, this study will provide a new option for the prevention and treatment of dental caries.

Curcumin Coated Orthosiphon Stamineus Leaf Extract Based Selenium Nanoparticle for Potential Tissue Engineering Applications

Curcumin is a type of polyphenol phytochemical that is bright yellow in colour and produced by the plant Curcuma longa. Despite its pharmacological properties, curcumin has low bioavailability, poor solubility, and undergoes rapid degradation. Nanoparticles (NPs) are used as a nanocarrier for drug delivery, to improve the stability and pharmacokinetics of the drug. Therefore, by coating curcumin over selenium NPs (SeNPs), the bioactivity, bioavailability, stability, and may increase the solubility of curcumin of SeNPs. This study aimed to synthesize the SeNPs from Orthosiphon stamineus leaf extract and coat it with curcumin and to characterize it and check its biocompatibility. Biosynthesis of SeNPs was carried out using plant extract of Evolvulus alsinoides and characterized using UV spectrophotometer, FT-IR, and SEM. Annexin V PI apoptotic and Hemolytic assay were used for checking biocompatibility. The UV-Vis spectrum gave a strong peak at 265 and 423 nm at various time intervals, indicating the SeNPs formation. Similarly, FT-IR has strong absorption bands at 3279, 1284, 1072, 1028, and cm−1 with wavelengths ranging from 4000-500 cm-1. SEM analysis of biosynthesized SeNPs showed a spherical shape. Our results suggest that curcumin-coated SeNPs possess greater biocompatibility towards PBMCs which was evaluated by Annexin V - PI assay and erythrocytes by hemolytic studies. Curcumin-coated Selenium nanoparticles were successfully synthesized by the biological method using leaf extract of Orthosiphon stamineus and reported as biocompatible using Flow cytometry. But a more detailed study should be done for implementing it in tissue engineering. Keywords: Selenium nanoparticle, Curcumin, Orthosiphon stamineus, Tissue Engineering.

Biosynthesis of selenium nanoparticles using cell-free extract of Xenorhabdus cabanillasii GU480990 and their potential mosquito larvicidal properties against yellow fever mosquito Aedes aegypti

Nanomaterials are successful due to their numerous applications in various domains such as cancer treatment, environmental applications, drug and gene delivery. Selenium is a metalloid element with broad biological activities and low toxicity especially at the nanoscale. Several studies have shown that nanoparticles synthesized from microbial and plant extracts are effective against important pests and pathogens. This study describes the bio fabrication of selenium nanoparticles using cell free extract of Xenorhabdus cabanillasii (XC-SeNPs) and assessed their mosquito larvicidal properties. Crystallographic structure and size of XC-SeNPs were determined with UV-a spectrophotometer, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), Energy-dispersive X-ray spectroscopy (EDAX), Zeta potential and Transmission electron microscopy (TEM). The significant surface plasmon resonance at 275 nm indicated the synthesis of XC-SeNPs from the pure cell-free extract of X. cabanillasii. The XRD result exhibits the crystalline nature of XC-SeNPs. The Zeta potential analysis confirmed that the surface charge of XC-SeNPs was −24.17 mV. TEM analysis revealed that synthesized XC-SeNPs were monodispersed, spherically shaped, and sized about 80–200 nm range. In addition, the larvicidal potentials of the bio-fabricated XC-SeNPs were assessed against the 4th-instar Ae. aegypti. XC-SeNPs displayed a dose-dependent larvicidal effect; the larval mortality was 13.3 % at the minimum evaluated concentration and increased to 72 % at higher dose treatments. The LC50 and LC90 concentration of XC-SeNPs against mosquito larvae were 79.4 and 722.4 ppm, respectively.

Biosynthesis of selenium nanoparticles by potential endophytic fungi Penicillium citrinum and Rhizopus arrhizus: characterization and maximization

AbstractFungal-mediated biosynthesis of selenium nanoparticles (SeNPs) is one of the promising biological-based nanomanufacturing process. On the other hand, the use of endophytic fungi in this respect has emerged as a new approach for green and cost-effective production of several nanoparticles. In the present study, two endophytic fungal isolates, identified as Penicillium citrinum and Rhizopus arrhizus morphologically and genetically using the ITS rRNA- gene. These fungal strains exhibited tolerance up to 40 mM NaSeO3 accompanied with red coloration of the medium that suggested selenite reduction and formation of selenium nanoparticles (SeNPs). The reduced selenite was quantified using inductively coupled plasma mass spectrometry (ICP-MS), and the results revealed that these fungi under the optimum growth conditions are able to transform > 99.0% of 3.0 mM selenite into elemental selenium. The crystalline structure, particle-sized distribution, and morphology of the purified selenium particles were extracted and characterized by different techniques including UV–Vis, X-ray diffraction and high-resolution transmission electron microscopy. The results indicated the production of regular spherical shapes of SeNPs with a majority of average size between 50 and 80 nm. Fourier transform infrared spectroscopy (FT-IR) of the produced particles revealed the presence of different functional groups that would be implicated in the synthesis process as bioreducers and capping agents. The results of optimum growth conditions revealed that the higher fungal growth resulted in the higher selenite reduction activity. Sabouraud’s and yeast extract-peptone-glucose (YPG) broth media are the best media for maximum growth of P. citrinum and R. arrhizus, respectively, and synthesis of SeNPs. The best carbon sources are sucrose and starch while NH4NO3 and NH4Cl are the best nitrogen sources for growth and synthesis of SeNPs by the fungal strains. Selenite reduction and biosynthesis of SeNPs by the fungi seemed to increase with increasing pH and maximized at alkaline pH value (9.0) being 97.94 and 97.13% for P. citrinum and R. arrhizus respectively. Initial selenite concentration markedly influenced SeNP production and the maximum rates were 96.94 and 98.47% recorded at 3.0 mM selenite for both fungi. In conclusion, the results were discussed in relation to the potentiality of these endophytic fungi for biosynthesis of SeNPs, and the favorable nutritional conditions for maximum production.

Ubiquitous Occurrence of Nano Selenium in Food Plants.

Selenium is an essential trace element in human nutrition. Recent findings suggest that the biosynthesis of selenium nano particles (SeNPs) in plants might be a ubiquitous phenomenon. We investigated the potential of SeNP biosynthesis in food plants and our core objective was to explore the commonness and possible ubiquitousness of nano selenium in food plants and consequently in the human diet. By growing a variety of plants in controlled conditions and the presence of selenite we found strong evidence that SeNPs are widely present in vegetables. The shoots and roots of seven different plants, and additionally Brazil nuts, were analyzed with single-particle inductively coupled plasma mass spectrometry with a focus on edible plants including herbs and salads. SeNPs were found in every plant of our study, hence we conclude, that SeNPs are common ingredients in plant-based food and are therefore eaten daily by most humans. Considering the concerning worldwide prevalence of selenium deficiency and the great physiological properties of SeNPs, we see a high potential in utilizing this discovery.

Biosynthesis of selenium nanoparticles by lactic acid bacteria and areas of their possible applications.

Lactic acid bacteria, being generally recognized as safe, are the preferred choice among other microbial producers of selenium nanoparticles. For successful production of SeNPs, it is necessary to take into account the physiological properties of the bacterium used as a biotransformer of inorganic forms of selenium in Se0. The antimicrobial and antioxidant activity of SeNPs allows to use them in the form of pure nanoparticles or biomass of lactic acid bacteria enriched with selenium in preparation of food, in agriculture, aquaculture, medicine, veterinary, and manufacturing of packing materials for food products. To attract attention to the promising new directions of lactic acid bacteria applications and to accelerate their implementation, the examples of the use of SeNPs synthesized by lactic acid bacteria in the mentioned above areas of human activity are described.

Biosynthesis of selenium nanoparticles by Candida albicans and them antimicrobial effects

Biosynthesis of selenium nanoparticles by Candida albicans and them antimicrobial effects

Effect of biosynthesized selenium nanoparticles using Nepeta extract against multidrug‐resistant Pseudomonas aeruginosa and Acinetobacter baumannii

The problems of drug resistance in bacteria have become one of the daily challenges of the clinical treatment of patients, which inevitably forces us to use agents other than common antibiotics. Among these, we can take help from different properties and applications of nanoparticles (NPs). In this work, we evaluate the antibacterial activity of biosynthesized selenium nanoparticles (SeNPs) against standard strains of multidrug-resistantPseudomonas aeruginosa and Acinetobacter baumannii. The production of biosynthesized SeNPs was proved by ultraviolet-visible, Fourier transform infrared, X-ray diffractometer,Field Emission Scanning Electron Microscopy, Dynamic light scattering, and Zeta potential methods. The cytotoxicity effect of SeNPs was investigated by MTT assay. Disk diffusion agar (DDA) and minimum inhibitory concentration (MIC) tests were performed on the mentioned bacteria using different classes of standard antibiotics and SeNPs separately. The impact of SeNPs combined with the desired antibiotics for better treatment of these infections was evaluated by checkerboard assay to determine the synergism effect. After the confirmation results based on the biosynthesis of SeNPs, both standard bacterial strains were susceptible to SeNPs and had a zone of inhibition using the DDA test. Also, the results of MICs showed that biosynthesized SeNPs in lower concentrations than antibiotics cause no growth of bacteria. On the other hand, according to the checkerboard assay, SeNPs had a synergistic effect with conventional antibiotics. The antibacterial sensitivity tests demonstrated the inhibition of bacterial growth in the presence of lower concentrations of SeNPs than common antibiotics. This property can be exerted in future applications to solve the drug resistance obstacle of microorganisms in bacterial diseases.

Biosynthesis of Selenium Nanoparticles and Evaluation of Its Antibacterial Activity against Pseudomonas aeruginosa

Background. A fundamental component of innate immunity is represented by skin that acts as a first aid against infection. The skin’s epithelial barriers, respiratory tract, and eyes directly contacting with the external environment have incremented the probability of infection. The opportunistic pathogen Pseudomonas aeruginosa causes various infections in immunocompromised hosts. In addition, one-third of P. aeruginosa clinical isolates are resistant to three or more antibiotics. Lately, lots of researchers concentrate on halophilic microorganisms due to affordable novel biomolecules. One of these biomolecules is metal nanoparticles. MNPs exhibited antimicrobial functionality against a variety of microbes. Amidst MNPs, SeNPs are one of the most extensively studied. In this study, halophilic bacteria from solar saltern were employed for the biosynthesis of SeNPs. Aim. This study aimed to evaluate the antibacterial properties of SeNPs which are synthesized by halophilic microorganisms. Result. The NPs were synthesized by Halomonas eurihalina intracellularly. The produced SeNPs were identified through various assays such as UV-Vis spectroscopy, XRD, DLS, FTIR, and SEM. UV-Vis spectroscopy confirmed the presence of SeNPs. In addition, the average particle size of SeNPs was 260 nm. FTIR confirmed the presence of the capping agent to inhibit the aggregation of SeNPs. Also, synthesized selenium nanoparticles have a natural crystalline nature that is verified by XRD. SEM also revealed the spherical shape. Furthermore, SeNPs represented significant antibacterial activity against P. aeruginosa. Conclusion. According to the obtained result, biosynthesized SeNPs demonstrated remarkable characteristics that make them profitable nonantibiotics and also decrease the morbidity and mortality associated with tissue infections.

Selenite Reduction by Proteus sp. YS02: New Insights Revealed by Comparative Transcriptomics and Antibacterial Effectiveness of the Biogenic Se0 Nanoparticles.

Biotransformation of selenite by microorganisms is an effective detoxification (in cases of dissimilatory reduction, e.g., to Se0) and assimilation process (when Se is assimilated by cells). However, the current knowledge of the molecular mechanism of selenite reduction remains limited. In this study, a selenite-resistant bacterium was isolated and identified as Proteus sp. YS02. Strain YS02 reduced 93.2% of 5.0 mM selenite to selenium nanoparticles (SeNPs) within 24 h, and the produced SeNPs were spherical and localized intracellularly or extracellularly, with an average dimension of 140 ± 43 nm. The morphology and composition of the isolated and purified SeNPs were characterized using dynamic light scattering (DLS), scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) spectrometry, and Fourier transform infrared (FTIR) spectroscopy. FTIR spectroscopy indicated the presence of proteins, polysaccharides, and lipids on the surface of the isolated SeNPs. Furthermore, the SeNPs showed excellent antimicrobial activity against several Gram-positive and Gram-negative pathogenic bacteria. Comparative transcriptome analysis was performed to elucidate the selenite reduction mechanism and biosynthesis of SeNPs. It is revealed that 197 genes were significantly upregulated, and 276 genes were significantly downregulated under selenite treatment. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that genes associated with ABC transporters, sulfur metabolism, pentose phosphate pathway (PPP), and pyruvate dehydrogenase were significantly enhanced, indicating selenite is reduced by sulfite reductase with PPP and pyruvate dehydrogenase supplying reducing equivalents and energy. This work suggests numerous genes are involved in the response to selenite stress, providing new insights into the molecular mechanisms of selenite bioreduction with the formation of SeNPs.

Biosynthesis of selenium nanoparticles using combinations of plant extracts and their antibacterial activity

Antimicrobial resistance is a significant public health problem, and the use of nanotechnology to control bacterial growth has increased, including multidrug-resistant ones. In this context, nanoparticles of different elements, mainly metals, such as silver, gold, and iron, have been extensively researched due to their efficient antimicrobial activity. Another element that stands out is selenium, which nanoparticles have high bioactivity and antibacterial action, although few studies report its use as a metallic nanoparticle. Therefore, the objective of this study was to perform the synthesis of selenium nanoparticles (SeNPs) from extracts of three plants: Allium cepa (onion), Malpighia emarginata (acerola), and Gymnanthemum amygdalinum (boldo). The synthesized nanoparticles were characterized by Dynamic Light Scattering (DLS), scanning electron microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (DRX). Antibacterial activity was evaluated by microdilution in broth, followed by the time-kill curve analysis. The bacterial strains tested were Streptococcus agalactiae, Staphylococcus aureus, methicillin-resistant S. aureus, Pseudomonas aeruginosa, and Escherichia coli. Hemolytic activity was also determined. The synthesized SeNPs had a size between 245 and 321 ​nm and mostly spherical morphology. Antimicrobial activity against all Gram-positive bacteria tested was observed, with minimal inhibitory concentrations ranging from 6.125 to 98 ​μg/ml, but without action in the tested Gram-negative bacteria. Low hemolytic capacity was observed, with CC50 ranging from 0.82 to 2.1 ​mg/ml. The antimicrobial activity and low hemolytic concentration indicate the possibility of use against Gram-positive bacteria, including multidrug-resistant ones, opening a wide variety of options for their applications.

Antibacterial and Antioxidant Activity of Garcinia mangostana Mediated Selenium Induced Nanoparticles: An In vitro Study

Introduction: The biosynthesis of selenium nanoparticles (SeNPs) has gained interest due to their unique chemical and biological properties, which are critical for their possible applications in a variety of fields. Garcinia mangostana (mangosteen) is a tropical fruit known for its edible pulp. The edible pulp accounts for just 30% of the total fruit weight, while the pericarp and seed are discarded. In response to rising public demand for naturally safe foods and items, we conducted a study to determine the antioxidant ability and antibacterial activity of mangosteen pericarp induced with selenium nano particles.
 Methods: The antioxidant capacities of selenium nano particles induced mangosteen’s pericarp were determined using 2,2- diphenyl-1-picrylhydrazyl (DPPH) assay, whereas agar well – diffusion technique was used to assess the antibacterial activity on chosen oral pathogens such as Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis.
 Results: In this study, the G. mangostana mediated selenium nanoparticles were synthesized using a green synthesis method. The maximum absorbance of the synthesized selenium nanoparticles was measured using a double beam UV visible spectrophotometer, resulting in a maximum absorbance of 325 nm. The Garcinia mangostana pericarp extract mediated selenium nanoparticles shows potent antimicrobial and antioxidant activity.
 Conclusion: The outcomes of our study could facilitate future application of mangosteen waste as a bio preservative in the food industry.

Biosynthesis of Selenium Nanoparticles (via Bacillus subtilis BSN313), and Their Isolation, Characterization, and Bioactivities.

Among the trace elements, selenium (Se) has great demand as a health supplement. Compared to its other forms, selenium nanoparticles have minor toxicity, superior reactivity, and excellent bioavailability. The present study was conducted to produce selenium nanoparticles (SeNPs) via a biosynthetic approach using probiotic Bacillus subtilis BSN313 in an economical and easy manner. The BSN313 exhibited a gradual increase in Se reduction and production of SeNPs up to 5–200 µg/mL of its environmental Se. However, the capability was decreased beyond that concentration. The capacity for extracellular SeNP production was evidenced by the emergence of red color, then confirmed by a microscopic approach. Produced SeNPs were purified, freeze-dried, and subsequently characterized systematically using UV–Vis spectroscopy, FTIR, Zetasizer, SEM–EDS, and TEM techniques. SEM–EDS analysis proved the presence of selenium as the foremost constituent of SeNPs. With an average particle size of 530 nm, SeNPs were shown to have a −26.9 (mV) zeta potential and −2.11 µm cm/Vs electrophoretic mobility in water. SeNPs produced during both the 24 and 48 h incubation periods showed good antioxidant activity in terms of DPPH and ABST scavenging action at a concentration of 150 µg/mL with no significant differences (p > 0.05). Moreover, 200 µg/mL of SeNPs showed antibacterial reactivity against Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 9027, and Pseudomonas aeruginosa ATCC 25923. In the future, this work will be helpful to produce biogenic SeNPs using probiotic Bacillus subtilis BSN313 as biofactories, with the potential for safe use in biomedical and nutritional applications.

Selenite bioreduction and biosynthesis of selenium nanoparticles by Bacillus paramycoides SP3 isolated from coal mine overburden leachate

A native strain of Bacillus paramycoides isolated from the leachate of coal mine overburden rocks was investigated for its potential to produce selenium nanoparticles (SeNPs) by biogenic reduction of selenite, one of the most toxic forms of selenium. 16S rDNA sequencing was used to identify the bacterial strain (SP3). The SeNPs were characterized using spectroscopic (UV–Vis absorbance, dynamic light scattering, X-ray diffraction, and Raman), surface charge measurement (zeta potential), and ultramicroscopic (FESEM, EDX, FETEM) analyses. SP3 exhibited extremely high selenite tolerance (1000 mM) and reduced 10 mM selenite under 72 h to produce spherical monodisperse SeNPs with an average size of 149.1 ± 29 nm. FTIR analyses indicated exopolysaccharides coating the surface of SeNPs, which imparted a charge of −29.9 mV (zeta potential). The XRD and Raman spectra revealed the SeNPs to be amorphous. Furthermore, biochemical assays and microscopic studies suggest that selenite was reduced by membrane reductases. This study reports, for the first time, the reduction of selenite and biosynthesis of SeNPs by B. paramycoides, a recently discovered bacterium. The results suggest that B. paramycoides SP3 could be exploited for eco-friendly removal of selenite from contaminated sites with the concomitant biosynthesis of SeNPs.

Green Synthesis of Selenium Nanoparticles by Cyanobacterium Spirulina platensis (abdf2224): Cultivation Condition Quality Controls.

Selenium nanoparticles (SeNPs) are well-known bioactive compounds. Various chemical and biological methods have been applied to SeNP synthesis. Spirulina platensis is a widely used blue-green microalgae in various industries. In this study, the biosynthesis of SeNPs using sodium selenite and Spirulina platens has been developed. The SeNP synthesis was performed at different cultivation condition including pH and illumination schedule variation. The SeNPs were characterized by FT-IR, XRD, size, and zeta potential measurements, and the antioxidant activities of selected SeNPs were evaluated by DPPH and FRAP assays. FT-IR analysis showed the production of SeNPs. The 12 h dark/12 h light cycles and continuous light exposure at pH 5 led to the production of stable SeNPs with sizes of 145 ± 6 and 171 ± 13 nm, respectively. Antioxidant activity of selected SeNPs was higher than sodium selenite. It seems that green synthesis is a safe method to produce SeNPs as well as a convenient method to scale-up this production.

Development of Selenium Nanoparticle Based Agriculture Sensor for Heavy Metal Toxicity Detection

The presence of heavy metals in increased concentrations in the environment has become a global environmental concern. This rapid increase in heavy metals in the environment is attributed to enhanced industrial and mining activities. Metal ions possess a lengthy half-life and property to bioaccumulate, are non-biodegradable and, thus, are a threat to the human health. A number of conventional spectroscopic and chromatographic techniques are being used for the detection of heavy metals, but these suffer from various limitations. Nano-based sensors have emerged as potential candidates for the sensitive and selective detection of heavy metals. Thus, the present study was focused on the synthesis of selenium nanoparticles (SeNPs) by using selenite-reducing bacteria in the development of a heavy metal toxicity biosensor. During the biosynthesis of selenium nanoparticles, supernatants of the overnight-grown culture were treated with Na2SeO32− and incubated for 24 h at 37 °C. The as-synthesized nanoparticles were characterized by UV–Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) and transmission electron microscopy (TEM) analyses. XRD and TEM results confirmed the formation of SeNPs in sizes ranging from 35 to 40 nm, with face-centered cubic (FCC) structures. The bioreduction process and validation of the formation of SeNPs was further confirmed by FTIR studies. The reduction in the biosynthesis of SeNPs using bacterial metabolite due to heavy metal cytotoxicity was analyzed by the colorimetric bioassay (SE Assay). The inhibition of selenite reduction and loss of red color in the presence of heavy metals may serve as a biosensor for heavy metal toxicity analysis. Thus, this biosensor development is aimed at improving the sensitivity and specificity of analytic detection.

Bioconversion of cheese whey into a hetero-exopolysaccharide via a one-step bioprocess and its applications

Continuing efforts have been made to produce functional exopolysaccharides (EPSs) using cheap substrates for valuable applications. Cheese whey is a lactose-rich byproduct of cheese-producing industries. In this research, a one-step bioprocess for the bioconversion of cheese whey to a hetero-exopolysaccharide using a ropy EPS producing strain Lactobacillus plantarum JNULCC001 with high β-galactosidase activity was performed. The prepared hetero-exopolysaccharide is named EPS-001 and composed of galactose, glucose, mannose, and arabinose with several functional groups, including carboxyl, hydroxyl, and amide groups, endowing its thermo-stable and highly negatively charged properties. The rheological analysis of the fermented whey indicates its high viscous and shear thinning (pseudoplastic non-Newtonian fluid) behavior, demonstrating the potential role of EPS-001 as a thickening and gelling agent. Besides, EPS-001 shows an excellent biosorption ability toward methylene blue (MB) and can serve as a stabilizer in the biosynthesis of selenium nanoparticles (SeNPs). Our research advances an alternative method for management of cheese whey, which may reduce its impact on the environment, and develops a novel value-added EPS for thickening, bioremediation and stabilizing nanomaterials.

Biogenic Synthesis of Selenium Nanoparticles with Edible Mushroom Extract: Evaluation of Cytotoxicity on Prostate Cancer Cell Lines and Their Antioxidant, and Antibacterial Activity

We report edible mushroom extract (EME) as a robust and environmentally friendly precursor for the biogenic synthesis of selenium nanoparticles (SeNPs). The as-synthesized SeNPs were characterized by UV-visible spectrophotometer (UV-vis), Fourier-transform infrared spectroscopy (FTIR), Transmission electron microscope (TEM), and Dynamic light scattering (DLS) techniques. The results obtained from TEM and DLS suggested that the SeNPs synthesized with EME are in the size of ~ 8 nm with a spherical shape and monodispersity. The occurrence of antioxidants in the EME has been confirmed with FTIR and thereby confirmed that flavonoids and phenolic compounds played a pivotal role in the biosynthesis of SeNPs from Na2SeO3. In addition, EME-SeNPs exhibited no cytotoxicity on the cell lines of prostate cancer (PC-3) at concentrations ranging from 0.5-1.5 μM. At a concentration of 0.25 mM against 1,1-diphenyl-2-picrylhydrazyl, the average scavenging level of EME-SeNPs was found to be > 80.20 %. Moreover, the percentage viability of gram-negative E.coli and gram-positive E.faecium was recorded at a high concentration of EME-SeNPs and found to be 82 % and 65 %, respectively.

Biosynthesis of selenium nanoparticles and their protective, antioxidative effects in streptozotocin induced diabetic rats

ABSTRACT Green synthesis of selenium nanoparticles (Se NPs) was performed by mixing Hibiscus sabdariffa (roselle plant) leaf extract with the solution of selenious acid (H2SeO3) under continuous stirring conditions resulting the roselle plant secondary metabolites conjugated Se NPs. The existence of functional groups of roselle plant secondary metabolites on the surface of prepared Se NPs was confirmed by Fourier transform infrared spectroscopy (FTIR). The formation of crystalline nanoparticles with anisotropic shape was confirmed by transmission electron microscopy (TEM) images. Furthermore, we also studied anti-oxidative and protective effects of Se NPs in streptozotocin (STZ) induced diabetes rats. These STZ induced diabetic rats were daily exposed to Se NPs or/and insulin treatment and the effect of Se NPs on the factors correlated to oxidative damage in the rat testes were evaluated. The biochemical studies showed that the Se NPs are capable to enhance the serum testosterone reduction caused due to STZ induced diabetes. In addition, Se NPs can significantly reduce the oxidative stress indicators of the testicular tissue such as nitric oxide and lipid peroxidation. However, the treatment of Se NPs on the STZ induced diabetic rats increased the activities of antioxidant enzyme as well as the glutathione content in testicular tissues. Furthermore, microscopic studies revealed that the Se NPs are capable of preventing the histological damage in the testes of STZ induced diabetic rats. Altogether, these results explained the possible effects of Se NPs in attenuating oxidative damage induced by diabetes, especially in the testicular tissue.