Pathogenicity of Microbes

Homogeneously distributed zinc nanoparticles (NPs) on the glass substrate were investigated for the transmittance, mechanical durability, and antibacterial effect. The buffered Ti NPs between Zn NPs and glass substrate were studied for an enhancement of the transmittance and mechanical endurance. The Ti NPs buffered Zn NPs showed a high transmittance of approximately 91.5% (at a wavelength of 550 nm) and a strong antibacterial activity for Staphylococcus aureus and Escherichia coli bacteria. The buffered Ti NPs are attractive for an excellent mechanical endurance of the Zn NPs. The Zn NPs did not require the protection layer to prevent the degradation of the performance for both the antibacterial effect and the transmittance. T he prevention of microbial surface contamination has become most crucial in today's health care system, and in food and pharmaceutical production. Human beings are often infected by microorganisms such as bacteria, viruses, and molds that often infect living environments. Silver nanoparticles or silver ions have been known to have strong inhibitory and bactericidal effects . Metallic nanoparticles are most promising as they show good antibacterial properties due to their large surface area to volume ratio, which is coming up as the current interest in the researchers due to the growing microbial resistance against metal ions, antibiotics and the development of resistant strains 7 . However, although the silver NPs showed a good antibacterial effect, they exhibited a strong toxicity to humans and a high cost for mass-production. Recently, transparent electronic devices were widely used as the electronic devices were integrated onto the glass panels. All of electronic devices were required to be applied for the antibacterial function, keeping a high transparency comparable to the glass panels. In addition, the mechanical durability of the glass panels with an antibacterial effect is required for longterm applications. Most of the reported results were mainly focused on the zinc oxide nanoparticles for antibacterial effect 10-13 . However, zinc oxide nanoparticles were mainly prepared by solution technique, which resulted in an inhomogeneous antibacterial effect due to the severe agglomeration of the nanoparticles. Zinc oxide nanoparticles are very difficult to establish the comparable transmittance to the glass substrate. Compared with silver NPs, zinc showed no toxicity to humans and a low-cost for mass-production. If the Zn NPs grown on the glass substrate exhibited an antibacterial activity and a comparable transmittance to the glass, because they were easily oxidized in air atmosphere for a long time and then changed to ZnO NPs, they were expected to be exhibited an antibacterial performance and a comparable transmittance to the glass substrate. To the best of our knowledge, the study to enhance both the transmittance and the antibacterial property using pure zinc NPs has not been reported. In the present study, zinc NPs instead of silver were chosen for antibacterial function and their influence on the transmittance was investigated using samples deposited by optimum conditions. For enhanced mechanical endurance of the zinc NPs on glass substrate, the Ti NPs were used as an adhesion layer between zinc NPs and glass. The reason that the Ti NPs deposited via a physical vapor deposition (PVD) process exhibited such a strong adhesion with the glass substrates was intensively investigated in the present study. Morphology, transmittance, antibacterial effect, and mechanical endurance of the zinc NP/glass was investigated for different structures such as Zn NPs/glass, Zn NPs/SiO 2 /glass, and Zn NPs/Ti NPs/glass.

This study focuses on the isolation and identification of Salmonella and Listeria from spiked food samples to examine the ideal conditions for food spoilage using selective enrichment and biochemical screening tests. Both bacteria are significant due to their high pathogenicity and environmental resistance. The experiment involves a four-step procedure: pre-enrichment, selective enrichment, selective plating/purification, and biochemical screening. Results indicated successful isolation of both bacteria, with various biochemical tests confirming their presence. This study underscores the importance of rigorous testing to ensure food safety and prevent foodborne illnesses.

Serratia liquefaciens is a gram-negative bacterium characterized by its motility due to peritrichous flagella and distinctive colony morphology, presenting as cream, pink, or red with smooth margins and an iridescent sheen. Optimal growth occurs between 10-36°C with pH tolerance from 5-9 and salt tolerance up to 4% NaCl. Isolation and identification are achieved using selective and differential media such as EMB and MAC agars, where it shows non-lactose-fermenting properties. Clinically, S. liquefaciens is pathogenic, causing transfusion-related infections and hospital-acquired infections due to its virulence factors like DNases and proteases. It also affects food quality by causing rot diseases in fruits. However, its virulence factors have shown potential for agricultural and pharmaceutical applications, including antibacterial and chitinolytic properties and remediation of heavy metal contamination in soils. Recent research highlights its ability to reduce arsenic accumulation in rice, demonstrating significant potential for agricultural biotechnology advancements.

ILICA nanoparticles (SNPs) are particles of silica which are in the range of 1 to 100 nm in size. In the present study, native silica nanoparticles (SNPs) have been prepared chemically using cetyltrimethyl ammonium bromide (CTAB) and sodium silicate as precursors. The prepared native SNPs were organically modified using the trioctylphosphine oxide (Cyanex921) to yield the modified CY-SNPs particles. The synthesized SNPs and CY-SNPs were characterized by using Scanning Electron Microscope (SEM) micrographs that showed spherical particles with an average size of 35 nm. The elemental analysis was performed using the Energy Dispersive Spectrum (EDS). For the native SNPs, The peaks recorded around 1.9 Kv and 0.5 Kv are the binding energies corresponding to Si and O, respectively. For the modified CY-SNPs, an additional peak around 2.1 Kv corresponding to phosphorous from the cyanex921 moiety was observed. The powder X-Ray Diffraction (XRD) analysis of the material further confirmed the crystallinity of the SNPs as evidenced by the diffraction pattern at broad peak centered at 2ϴ=20o which indicates that the sample is amorphous. Fourier Transform Infra-Red Spectroscopy (FTIR) spectra indicated the loading of cyanex921 to the surface of the native SNPs. The antimicrobial activities of native and phosphine modified SNPs were assessed against Gram-positive and Gram-negative microorganisms using the minimum inhibitory concentration (MIC) studies. The results obtained showed that CY-SNPs have potential antibacterial effects against the gram positive microorganisms, viz. methicillin resistant staphylococcus aureus (MRSA) and the gram negative microorganisms viz. E.coli, klebsiella. Sp. and pseudomonas sp. and the MIC corresponding to each type has been determined. The native silica nanoparticles have not shown any antibacterial effect against the four bacteria strains previously mentioned over concentrations 0.10-5.0 mg/mL. The mechanism of the antibacterial activity of the proposed phosphine modified silica nanoparticles was discussed. The present study can generally approve the qualification of caynex921modified silica nanoparticles for the use as antibacterial agents.

Purpose: The increase of bacterial resistance to common antibacterial agents is one of the major problems of health care systems and hospital infection control programs. In this study, antimicrobial activity of titanium dioxide (TiO2 ) and zinc oxide (ZnO) nanoparticles (NPs) was investigated against E. coli, Salmonella enteritidis, Listeria monocytogenes, and Staphylococcus aureus pathogenic bacteria by determining sensitivity coefficient and kinetics of bacterial death. Methods: Antimicrobial tests were performed with ~106 CFU/mL of each bacterium at baseline. At first, minimum inhibitory concentration (MIC) was concluded by the dilution method and then, death kinetic and susceptibility coefficient of NPs suspensions was determined at 0 to 360 min. treatment time. Results: The results of this study revealed that, the highest susceptibility was observed for L. monocytogenes (Z=0.025 mL/μg) to TiO2 NPs, whereas the lowest susceptibility was obtained in the reaction of ZnO NPs with S...

Purpose: The increase of bacterial resistance to common antibacterial agents is one of the major problems of health care systems and hospital infection control programs. In this study, antimicrobial activity of titanium dioxide (TiO2 ) and zinc oxide (ZnO) nanoparticles (NPs) was investigated against E. coli, Salmonella enteritidis, Listeria monocytogenes, and Staphylococcus aureus pathogenic bacteria by determining sensitivity coefficient and kinetics of bacterial death. Methods: Antimicrobial tests were performed with ~106 CFU/mL of each bacterium at baseline. At first, minimum inhibitory concentration (MIC) was concluded by the dilution method and then, death kinetic and susceptibility coefficient of NPs suspensions was determined at 0 to 360 min. treatment time. Results: The results of this study revealed that, the highest susceptibility was observed for L. monocytogenes (Z=0.025 mL/μg) to TiO2 NPs, whereas the lowest susceptibility was obtained in the reaction of ZnO NPs with S...

Objectives: Silver nanoparticles (AgNPs) possess unique features among noble metal nanoparticles due to their wide range of applications in various field including medicine, environmental safety, etc. The present study relies on eco-friendly, cost effective method for the synthesis of AgNPs. Methods: AgNPs were rapidly synthesized from AgNO3 Results: X-ray diffraction analysis showed that the nanoparticles formed in the present synthesis were crystalline in nature. FT-IR analysis showed the presence of possible biomolecules needed for reducing silver ions. Further, antibacterial activity of synthesized AgNPs showed effective inhibition against pathogenic microbes. In addition, these green synthesized nanoparticles were shown to exhibit potential cytotoxic effect on MCF-7 cell line in dose dependent manner. using aqueous leaf extract of O. heracleoticum L. as reducing as well as capping agent. Synthesized AgNPs were characterized with the help of FE-SEM, XRD, EDS and UV-vis absorption spectroscopy. FE-SEM showed the spherical nature of nanoparticles with the size ranging from 30-40 nm. In addition, their antibacterial activities against standard bacterial pathogens were evaluated as per the standard disk diffusion method. Further, cytotoxicity potential of AgNPs were also determined using the MTT assay. Conclusion: It has been demonstrated that O. heracleoticum L. plant extract could be used as a proficient green reducing agent for the synthesis of AgNPs. Further, these synthesized AgNPs were shown to exhibit effective antibacterial effect against pathogens and potential cytotoxic effect on MCF-7 cells.

This article investigates the effect of Ni 2+ content on structural (XRD, XPS), morphological (TEM), and magnetic behaviors of silica magnesium zirconium copper nanoceramics calcined at 800 °C. The solgel route is followed for the silica magnesium zirconium copper/(0.0-0.7) Ni 2+ samples preparation. X-ray photoelectron spectroscopy is employed to analyze the chemical states of elements for the samples. The three representative binding energy magnitudes for O, Ni, and Cu reside at 534, 857, and 979 eV, consecutively. The saturation magnetization constricts with the elevation of Ni 2+ content, while the magnetic hysteresis loop resembles the superparamagnetic attitude. The optical spectra present the possibility of direct and indirect transitions in the prepared nanoceramics. Energy gap (value and type), refractive index, and real and imaginary dielectric constant were extracted. The energy gap approaches 3.75 eV and 3.71 eV for direct and indirect transitions correspondingly with (0.7) Ni 2+. The antimicrobial and the toxicity performance of all inspected nanocomposites were conducted against pathogenic microbes. The attained results evidenced that SMZC-0.7Ni possesses energetic antimicrobial potential against all targeted microbes. The investigated SMZC-0.7Ni nanocomposite functioned to eradicate frequent waterborne pathogens in wastewater at an appropriate dose (100 mg/L), demonstrating that SMZC can be utilized as a competent disinfectant in the municipal wastewater decontamination process. Inherently, SMZC-0.7Ni can be employed as an excellent nano-weapon against multiple dangerous microorganisms. Water is amongst the necessities of human civilization and other life forms in the universe, as it is utilized in various daily activities. Industrial development significantly contributes to the creation of sewage, which is often dumped untreated into bodies of water, resulting in pollution 1. Due to rising costs of freshwater resources, increasing population, and a range of climatic and environmental challenges, it is estimated that over 1.1 M people have no access to an appropriate water supply 2. Likewise, pathogenic microbes encompassing bacteria, viruses, fungi, protozoa, and rickettsia, trigger 80% of the total illnesses in underdeveloped countries, representing a severe hazard to public health and claiming millions of lives each year around the world 3. The management of wastewater could be a dormant solution to pollution reduction; yet, typical treatment procedures are insufficient to eliminate new pollutants and meet stringent water quality criteria entirely. The chlorination process is employed to inactivate pathogenic microorganisms in wastewater treatment plant effluents (WWTPs) before the point of discharge. Chlorination and ultraviolet (UV) irradiation are the most frequently applied disinfecting techniques 4. Nevertheless, the difficulties these two approaches encounter, such as the

Magnesium oxide nanoparticles (MgO-NPs) were synthesized using the fungal strain Aspergillus terreus S1 to overcome the disadvantages of chemical and physical methods. The factors affecting the biosynthesis process were optimized as follows: concentration of Mg(NO3)2·6H2O precursor (3 mM), contact time (36 min), pH (8), and incubation temperature (35 °C). The characterization of biosynthesized MgO-NPs was accomplished using UV-vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy—energy dispersive X-ray (SEM-EDX), X-ray diffraction (XRD), and dynamic light scattering (DLS). Data confirmed the successful formation of crystallographic, spherical, well-dispersed MgO-NPs with a size range of 8.0–38.0 nm at a maximum surface plasmon resonance of 280 nm. The biological activities of biosynthesized MgO-NPs including antimicrobial activity, biotreatment of tanning effluent, and chromium ion removal were invest...

L-Asparaginase (L-asparagine aminohydrolase, E.C. 3.5.1.1) has been proven to be competent in treating Acute Lymphoblastic Leukaemia (ALL), which is widely observed in paediatric and adult groups. Currently, clinical L-Asparaginase formulations are derived from bacterial sources such as Escherichia coli and Erwinia chrysanthemi. These formulations when administered to ALL patients lead to several immunological and hypersensitive reactions. Hence, additional purification steps are required to remove toxicity induced by the amalgamation of other enzymes like glutaminase and urease. Production of L-Asparaginase that is free of glutaminase and urease is a major area of research. In this paper, we report the screening and isolation of fungal species collected from the soil and mosses in the Schirmacher Hills, Dronning Maud Land, Antarctica, that produce L-Asparaginase free of glutaminase and urease. A total of 55 isolates were obtained from 33 environmental samples that were tested by co...

This study examines substances from plant leaves of Azadirachta indica and Melia azedarach extracted with methanol (80%) and then successively fractionated with increasing gradient polarity solvents. The methanol extract from the two plant leaves was selected to be incorporated with nanocomposites because of their high antimicrobial activities. HPLC analysis was performed for the determination of total phenolics and avonoids. LC-ESI-MS positive ion acquisition mode revealed the presence of four main chemical classes; limonoids, triterpenes, fatty acids, and phenolics. Sol-gel processes were adapted to prepare CaO/chitosan composite loaded with the methanol extract of the two plant leaves, acting as innovative antibacterial agents. The fabricated nanocomposites were characterized by XRD, TEM, SEM, and FT-IR methods. Minimal bactericidal concentrations (MBC) were established by agar plating using bacteria treated with MIC and at least 2 concentrations double-higher than the MIC. Bio lm was cultivated in the presence of sub-MICs of the extracts and the nanocomposites, followed by quanti cation with the crystal violet assay. The examined chitosan-CaO-based hybrid nanocomposites loaded with the methanol fractions from the leaves of A. indica and M. azedarach had an excellent performance as bio lm inhibitors. This indicates their good potential for biomedical applications.

Endophytic fungi have been in the spotlight as a reservoir of novel agents with diverse bioactivities. Similarity in chemical diversity with the host plant makes them an amenable target for industrial interventions. A wide range of compounds as secondary metabolites and enzymes are manufactured inside the endophytic fungal factory. However, utilization of endophytic fungi as industrially imperative enzyme producers has been a scarce event. The present study was conducted to bio-prospect the fungal endophytes present in the high altitude medicinal plants of Uttarakhand, as industrially imperative enzyme producers. A total of 58 different endophytic isolates were obtained from Pinus sabiniana, Cinnamomum tamala, Cinnamomum verum, Ocimum tenuiflorum and Rhododendron arboreum. Endophytic fungal colonization was highest, 31%, in Pinus sabiniana. The pure isolates were further explored for the production of amylases, cellulases, proteases and L-asparaginase. Out of 58 isolates, 40 isolate...

The present study was carried out to isolate endophytic fungi from Ocimum sanctum and Aloe vera and to assess their antifungal activity against Rhizoctonia solani, Fusarium oxysporum, Colletotrichum falcatum and Helminthosporium maydis. The isolated fungi were further evaluated for production of extracellular enzymes such as amylase, cellulase, chitinase, pectinase, laccase, lipase and urease. During the study 18 endophytic fungi were isolated from leaves, stem and roots of O. sanctum and Aloe vera which are different from each other morphologically. AVR1 and AVR3 show antagonistic activity towards the Fusarium oxysporum. T2S1 and AVL1 were found positive for amylase, TL1, AVR1, and AV2L1 were found positive in cellulase production while only AVR3 was found positive for chitinase production. AVR3, TL2, TL3, TS1, AV2R1, T2S1 and T2L1 were positive in pectinase production, none of the isolates were found positive in laccase production, only AVL1 was found positive in lipase production and TL2, T2R1, AVL1, AVL4, T2L1 and TL3 were positive in urease production. The results of the study suggest that endophytic fungi associated with O. sanctum and Aloe vera are potential agents for antimicrobial activity and a vast source of enzyme.

The nanostructured material, due to their outstanding applications in various fields of science and technology; metal and metal oxide nano are exclusively explored in the progress of nanosized materials. The transition metal oxides including CuO is are used for magnetic storage devices, solar energy applications, sensors, as a catalyst in reactions, as electrode materials in supercapacitors and to tune the semiconducting properties of materials. The current work focuses on the synthesis of CuO nanoparticles (NPs) by combustion technique for various annealing (100°C and 300°C) using ascorbic acid as a capping agent. The XRD pattern confirms that the CuO NPs exhibit the monoclinic structure. The optical properties are investigated using UV-Vis absorption spectra. Further, the refractive index, optical dielectric constant and bulk modulus were investigated using the specific empirical model as a function of temperature. The FTIR spectrum shows that the band in the range 450-500 cm −1 confirms the formation of CuO NPs. The SEM images revealed that the spherical surface morphology of the CuO NPs. The Elemental analysis and the particle size were confirmed by elemental dispersive X-ray analysis (EDX) and particle size analyzer. Moreover, the antibacterial activity of CuO nanoparticles was investigated using E. coli, S. typhi, M. luteus, P. fluorescent, S. flexneri, and V. cholera bacteria.

Endophytic fungi residing in the host plants are well known for the production of industrially significant enzymes. This study deals with the isolation of fungal endophytes and the screening of extracellular enzymes from nine different plants of the family Lamiaceae with potent medicinal properties. Overall, 40 endophytic fungi (LCJ401-LCJ440) were isolated from selected medicinal plants. The isolated endophytic fungi were evaluated for their capability to synthesize industrially important enzymes like amylase, protease, cellulase, laccase and L-Asparaginase in specific solid media. The results indicated that 45%, 37.5%, 35%, 32.5% and 52.5% of isolates could produce amylase, protease, cellulase, laccase and L-Asparaginase enzymes respectively. Based on the primary screening, the L-Asparaginase enzyme was more dominant and therefore the promising L-Asparaginase producing isolates were estimated by the nesselarization method. Of these, LCJ413, LCJ428, LCJ432 and LCJ438 were known to produce a high amount of L-Asparaginase. These isolates were subject to molecular analysis by 18S rRNA sequencing and MEGA software was used to construct a phylogenetic tree. The endophytic fungi identified were LCJ413 (Curvularia sp.), LCJ428 (Arxotrichum sp.), LCJ432 and LCJ438 (Fusarium sp.). Findings here revealed that fungal endophytes of Lamiaceae taxa have high L-Asparaginase-producing potency and can be exploited as a substitute reservoir for anticancer enzyme production.

l-Asparaginase is a therapeutically and industrially-competent enzyme, acting predominantly as an anti-neoplastic and anti-cancerous agent. The existing formulations of prokaryotic l-asparaginase are often toxic and contain l-glutaminase and urease residues, thereby increasing the purification steps. Production of l-glutaminase and urease free l-asparaginase is thus desired. In this research, bioprospecting of isolates from the less explored class Agaricomycetes was undertaken for l-asparaginase production. Plate assay (using phenol red and bromothymol blue dyes) was performed followed by estimation of l-asparaginase, l-glutaminase and urease activities by Nesslerization reaction for all the isolates. The isolate displaying the desired enzyme production was subjected to morphological, molecular identification, and phylogenetic analysis with statistical validation using Jukes-Cantor by Neighbour-joining tree of Maximum Likelihood statistical method. Among the isolates, Ganoderma aust...

We used a green sol-gel synthesis method to fabricate a novel nanoporous copper aluminosilicate (CAS) material. Nanoporous CAS was characterized using X-ray powder diffraction (XRD), field emission transmission and scanning electron microscopies (FE-TEM/FE-SEM), Fourier transform infrared (FTIR) spectroscopy, and optical analyses. The CAS was also evaluated for use as a promising disinfectant for the inactivation of waterborne pathogens. The antimicrobial action and minimum inhibitory concentration (MIC) of this CAS disinfectant were determined against eight microorganisms (Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Candida albicans, and Aspergillus niger). An antimicrobial susceptibility testing of CAS was measured. Results of disc diffusion method pointed out that the diameters of the zone using well diffusion were wider than disc diffusion methods, and the findings also showed that the MIC of the CAS disinfectant against E. coli, S. enterica, and P. aeruginosa was 100 mg/L within 20 min of contact time. Meanwhile, the MIC of the CAS disinfectant was 100 mg/L within 40 min of contact time for the other strains. The efficacy of antimicrobial action (100%) reached within 20 to 40 min against all tested microbes. Herein, the antimicrobial susceptibility testing of CAS disinfectant showed no toxicity for human and bacterial cells. It can be concluded that nanoporous CAS is a promising, economically, and worthy weapon for water disinfection.

Eco-friendly copper aluminosilicate nanoparticles doped with cobalt nanoparticles were prepared via the sol-gel route. The samples were calcined at 800°C to induce high crystallization, which would potentially enhance their structural, spectroscopic and antimicrobial properties. Structural and spectroscopic characterization were measured using X-ray diffraction, Field emission-scanning electron microscopy, Fourier Transformed Infrared, UV-Vis-absorbance and UV/Vis diffuse reflectance spectra. The product revealed the formation of a crystalline cubic phase of (CAS) and orthorhombic (β-Co 2 SiO 4) phase. The antimicrobial susceptibility testing of nanocrystalline CAS, 5Co-CAS and 9Co-CAS as magnetic nanocomposites was evaluated using agar diffusion and broth dilution methods against Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Candida albicans, and Aspergillus niger. The toxicity assays for each antiseptic were also conducted. The incorporation of cobalt ions in the silicate base material was observed to be highly cross-linked during the formation process. UV-Vis-absorbance for the samples gave a red shift and noticeable increases in the band gap with the values 1.42, 1.43, 1.52 and 1.50 eV, respectively. The results showed that 9Co-CAS was the most potent antiseptic followed by 5Co-CAS and CAS.

The following study was performed chiefly to analyze the antimicrobial activity of CdO/ZnO-ESM nanocomposites. A unique method was used for the synthesis of CdO/ZnO-ESM nanocomposites using an eggshell membrane as a bio-template which acts as both reducing and stabilizing agents; whereas cadmium nitrate and zinc nitrate were employed as metal precursors. The prepared samples were characterized by the following techniques such as TGA, PXRD, DRS-UV-Visible reflectance, FT-IR, HR-SEM, EDAX, Zeta potential, and Photoluminescence analysis. The prepared samples were subsequently tested for antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus and Bacillus sp.) and Gram-negative bacteria (Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Salmonella enterica, and Vibrio sp.) using agar well diffusion method. The minimum inhibitory concentration was determined by the broth microdilution method. The maximum inhibition zone of 24 mm, was observed in Salmonella enterica at a concentration (30 μg/mL) of CdO/ZnO-ESM nanocomposites, while the highest MIC value was observed in Bacillus sp. at a concentration (1.95 μg/mL) of these nanocomposites. The result of this study showed that CdO/ZnO-ESM nanocomposites have an exceptional antimicrobial activity against both Gram-positive and Gram-negative bacteria.

The novel V 2 O 5 /ZnO nanocomposite, an antibacterial material, was synthesized through a simple, low-cost, and energysaving approach. The eggshell membrane was used for the first time as a bio-template, reducing and stabilizing agent during this synthesis. Ammonium metavanadate and zinc nitrate hexahydrate (1:1) were the metal precursors. The synthesis involved soaking of an eggshell membrane with the metal solution at room temperature followed by the calcination. The as-prepared and synthesized V 2 O 5 /ZnO nanocomposite was characterized by thermal, spectroscopic, and microscopic techniques. Besides, this study determined the antibacterial activity (agar well-diffusion test) and minimum inhibition concentration (resazurin microdilution test) of V 2 O 5 /ZnO nanocomposite against Gram-positive bacteria (Staphylococcus aureus and Bacillus sp.) and Gram-negative bacteria (Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Salmonella enterica, and Vibrio sp.). The annealing temperature (550 °C) for V 2 O 5 /ZnO nanocomposite was determined by the TGA-DTA study. The XRD analysis of V 2 O 5 /ZnO nanocomposite revealed the formation of both the orthorhombic (V 2 O 5) and hexagonal wurtzite (ZnO) structures with the crystallite size of 20 nm. The FT-IR spectrum indicated the stretching vibration of V=O and Zn-O at 925 and 473 cm −1 , respectively. The Raman spectra also confirmed the formation of the orthorhombic and hexagonal wurtzite structure. From DRS UV-visible spectroscopy, the optical band-gap energy of V 2 O 5 /ZnO nanocomposite was equal to 2.05 eV. The HR-SEM study of V 2 O 5 /ZnO nanocomposite depicted large spheres as well as small particles. The EDX analysis established only vanadium (32.45 wt %), oxygen (57.06 wt %), and zinc (10.48 wt %). The zeta-potential analysis of V 2 O 5 /ZnO nanocomposite showed moderate stability with a negative value of − 42.9 mV. The study of antibacterial activity exhibited a high zone of inhibition (23 mm) against the Staphylococcus aureus and Bacillus sp. at 30 μg mL −1 , and the minimum inhibition concentration (MIC) value was observed in Bacillus sp. at 0.49 μg mL −1. The V 2 O 5 /ZnO nanocomposite can be employed in biomedical applications as an antibacterial agent.

Magnesium oxide nanoparticles (MgO-NPs) were synthesized using the fungal strain Aspergillus terreus S1 to overcome the disadvantages of chemical and physical methods. The factors affecting the biosynthesis process were optimized as follows: concentration of Mg(NO3)2·6H2O precursor (3 mM), contact time (36 min), pH (8), and incubation temperature (35 °C). The characterization of biosynthesized MgO-NPs was accomplished using UV-vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy—energy dispersive X-ray (SEM-EDX), X-ray diffraction (XRD), and dynamic light scattering (DLS). Data confirmed the successful formation of crystallographic, spherical, well-dispersed MgO-NPs with a size range of 8.0–38.0 nm at a maximum surface plasmon resonance of 280 nm. The biological activities of biosynthesized MgO-NPs including antimicrobial activity, biotreatment of tanning effluent, and chromium ion removal were invest...

Seven novel synthetic heterocyclic compounds containing naphthofurans were evaluated for their inhibitory effect on Phomopsis azadirachtae, the causative agent of destructive die-back disease of neem. Twigs of Azadirachta indica (Neem) infected with die-back were collected and were analyzed to determine the pathogen. Phomopsis azadirachtae the causal organism was isolated on malt extract agar from die-back infected neem twigs. They were identified by PCR based molecular methods. Phomopsis genus specific primers (5.8S r-DNA) were then used for the confirmation of P. azadirachtae-the causative agent of die-back of neem by Polymerase chain reaction (PCR). Studies revealed the amplification of expected 141bp DNA in P. azadirachtae isolated from the diseased trees confirming the causal organism of die-back of neem. Studies revealed a very effective in vitro control of P.azadirachtae mycelia growth at very significant concentration.

With the fast development of nanomaterials and nanotechnology, environmental nanotechnology has captivated increasing concerns in the past few decades. There are several nanomaterials in the earth, and a variety of modification held in future development. These Zinc nanoparticles illustrate antibacterial, anti-corrosive, and UV filtering premises. In the study, we determine the antibacterial action of nanoparticles of Zinc Oxide for the curing of city wastewater. Sample of wastewater were collected from sewage water, make three samples the sample I exposed to UV, and Sample II is treated with chlorine while other is control. Samples were than cultured on NA and EMB agar, next day microscopy, biochemical test, spot test to identify the specie was performed accordingly. From control sample Escherichia coli while from UV exposed and chlorine treated organism identified as Staphylococcus. epidermidis  respectively, Nano particles of Zinc were prepared by mechano-chemical method then the...

Escherichia coli have been associated with severe and sometimes fatal infections like pyelonephritis, septicemia, endocarditis, meningitis, urinary tract infections (UTIs), epidemic diarrhea of adults and children. The situation is worsening due to increased antibiotic resistance plasmid genes of the bacteria. The study correlates plasmids with drug resistance of clinical isolates of E.coli. A total of 52 E.coli clinical isolates from different human clinical specimens (comprising of urine, blood, faeces, hand and wound swab) were obtained from patients in hospitals in Lagos, Nigeria and their antimicrobial susceptibility pattern and plasmid profiles were tested against methanolic leaf extract of Azadirachta indica and some selected antibiotics. Thirteen isolates of E.coli were selected and cultured in nutrient broth in the presence and absence of 1% SDS solution. Very high resistance levels (≥75) were detected against ciprofloxacin, amoxicillin. ampicillin, tetracycline, Co-Amoxiclavand imipenem,while nitrofurantoin (96.2%), gentamicin (88.5%), ofloxacin (78.9%), chloramphenicol (71.2%) and A.indica (65.4%) were highly sensitive to the E.coli strains. Some of the isolates possessed single sized plasmid while others had multiple plasmids with different sizes which ranged from 2.1 kb to 21.7 kb. High antibiotic resistances were detected from isolates with high molecular weight plasmids.

We used a green sol-gel synthesis method to fabricate a novel nanoporous copper aluminosilicate (CAS) material. Nanoporous CAS was characterized using X-ray powder diffraction (XRD), field emission transmission and scanning electron microscopies (FE-TEM/FE-SEM), Fourier transform infrared (FTIR) spectroscopy, and optical analyses. The CAS was also evaluated for use as a promising disinfectant for the inactivation of waterborne pathogens. The antimicrobial action and minimum inhibitory concentration (MIC) of this CAS disinfectant were determined against eight microorganisms (Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Candida albicans, and Aspergillus niger). An antimicrobial susceptibility testing of CAS was measured. Results of disc diffusion method pointed out that the diameters of the zone using well diffusion were wider than disc diffusion methods, and the findings also showed that the MIC of the CAS disinfectant against E. coli, S. enterica, and P. aeruginosa was 100 mg/L within 20 min of contact time. Meanwhile, the MIC of the CAS disinfectant was 100 mg/L within 40 min of contact time for the other strains. The efficacy of antimicrobial action (100%) reached within 20 to 40 min against all tested microbes. Herein, the antimicrobial susceptibility testing of CAS disinfectant showed no toxicity for human and bacterial cells. It can be concluded that nanoporous CAS is a promising, economically, and worthy weapon for water disinfection.

Wollastonite clusters doped with/without CuO (0.0-10.0 g/100 g nominal CaSiO3) were prepared via precipitation route. This method is suitable for the development of wollastonite clusters, as ingenious compared with other costly methods. Wollastonite was developed after heat-treatment at 550°C/2 h, as rounded to sub rounded nano-crystals at the size of 20-50 nanometers. The cluster powders were quantitatively tested on Gram negative bacteria (Pseudomonas aeruginosa and Escherichia coli), Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Fungi (Aspergillus niger and Fusarium solani) using the agar diffusion technique. CuO-containing samples showed good activity against E. coli, P. aeruginosa and A. niger fungi. Gram negative bacteria Pseudomonas aeruginosa and fungi Aspergillus niger were detected to be most susceptible to the 5.0% CuO concentration with an inhibition zone diameter (IZD) between 30 mm and 22 mm, respectively. Moreover, E. coli showed an IZD of 2...

Phomopsis azadirachtae Sateesh, Bhat and Devaki is the causal agent of die-back disease of neem. Six isolates of P. azadirachtae collected from different geographical regions of Tamilnadu were subjected to SDS-PAGE to study the variation among the isolates. Mycelial soluble proteins extracted from the six isolates exhibited marked variations in their electrophoretic protein profile. A few bands were common to all the isolates and each isolate also had a few specific bands. Soluble proteins were resolved into 42 bands of different molecular weights. Similarity index obtained ranged from 29.63% to 59.26%. Above findings indicate the existence of variability in P. azadirachtae isolates and its heterogeneous nature, revealing the genetic diversity of the pathogen.

Antimicrobial resistance (AMR) is the development of resistance by pathogenic microbes to an antimicrobial agent that was previously proven to be an effective treatment. The most significant concern at this time is pathogenic bacteria as they are starting to develop resistance to antibiotics faster than other types of organisms and pose a greater threat. Bacteria are able to develop antimicrobial resistance through gene transfer or mutations in the genome of the bacterial strain. Currently, there is an urgent need for methods that can effectively treat prevalent bacterial infections. This can be achieved through either the creation of new and improved antimicrobial agents or utilizing synthetic biology at the genetic level to achieve immunity. Many fields in modern medicine involve effective antibiotic drugs as part of the treatment of the disease. For example, organ transplants, chemotherapy for cancer, bone replacement surgery, etc. could not be performed without effective antibiotics. Infections due to multi-resistant bacterial strains are one of the main causes of death in patients undergoing these procedures. When infections become resistant to first-line antimicrobials, they must be switched to second or thirdline antimicrobials, which are usually more expensive. A patient affected by antibacterial resistant strains might need more expensive treatments, specialized equipment, and more intensive care, which may lead to elevated costs in addition to the original treatment cost. Any data collected regarding the effects of antimicrobial-resistant infections are hard to rely on as infection rates increase rapidly every year, which is a problem.

Fungal species that establish an endophytic role inside the tissues of medicinal plants are known to produce a wide range of biologically active metabolites and enzymes. In the present study, the most dominant and representative endophytic fungal species of five ethno-medicinal plants prevalent in the pristine sacred forests of Meghalaya, were screened for their ability to produce amylase, cellulase, protease, lipase, and xylanase. Each of endophytic fungal isolates showed a wide range of enzyme activity. Mycelial biomass generation and root colonization, in addition to the enzyme activity of the endophytic fungal isolates, provided insights into their probable origin and ecological roles within the plant host.

 Activated carbon is greatly used to adsorb toxic heavy metals from water bodies. Simultaneous removal of such pollutants and pathogenic impurities is essential for safe drinking water. In this study, silver nanoparticles (NPs) doped activated carbon (AC) composite was fabricated via hydrothermal technique and green synthesis technique using commercial activated carbon powder and silver nitrate solution. Several analytical techniques, including scanning electron microscopy (SEM), energy dispersive x-ray (EDX), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirmed the formation of silver nanoparticles on the surface and pores of AC. The prepared composite materials were accessed for their anti-bacterial property using Escherichia coli and Staphylococcus aureus and found that such materials have good antibacterial activity which shows that as fabricated composite can be used potentially for water treatment.

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ILICA nanoparticles (SNPs) are particles of silica which are in the range of 1 to 100 nm in size. In the present study, native silica nanoparticles (SNPs) have been prepared chemically using cetyltrimethyl ammonium bromide (CTAB) and sodium silicate as precursors. The prepared native SNPs were organically modified using the trioctylphosphine oxide (Cyanex921) to yield the modified CY-SNPs particles. The synthesized SNPs and CY-SNPs were characterized by using Scanning Electron Microscope (SEM) micrographs that showed spherical particles with an average size of 35 nm. The elemental analysis was performed using the Energy Dispersive Spectrum (EDS). For the native SNPs, The peaks recorded around 1.9 Kv and 0.5 Kv are the binding energies corresponding to Si and O, respectively. For the modified CY-SNPs, an additional peak around 2.1 Kv corresponding to phosphorous from the cyanex921 moiety was observed. The powder X-Ray Diffraction (XRD) analysis of the material further confirmed the crystallinity of the SNPs as evidenced by the diffraction pattern at broad peak centered at 2ϴ=20o which indicates that the sample is amorphous. Fourier Transform Infra-Red Spectroscopy (FTIR) spectra indicated the loading of cyanex921 to the surface of the native SNPs. The antimicrobial activities of native and phosphine modified SNPs were assessed against Gram-positive and Gram-negative microorganisms using the minimum inhibitory concentration (MIC) studies. The results obtained showed that CY-SNPs have potential antibacterial effects against the gram positive microorganisms, viz. methicillin resistant staphylococcus aureus (MRSA) and the gram negative microorganisms viz. E.coli, klebsiella. Sp. and pseudomonas sp. and the MIC corresponding to each type has been determined. The native silica nanoparticles have not shown any antibacterial effect against the four bacteria strains previously mentioned over concentrations 0.10-5.0 mg/mL. The mechanism of the antibacterial activity of the proposed phosphine modified silica nanoparticles was discussed. The present study can generally approve the qualification of caynex921modified silica nanoparticles for the use as antibacterial agents.

l-Asparaginase is a therapeutically and industrially-competent enzyme, acting predominantly as an anti-neoplastic and anti-cancerous agent. The existing formulations of prokaryotic l-asparaginase are often toxic and contain l-glutaminase and urease residues, thereby increasing the purification steps. Production of l-glutaminase and urease free l-asparaginase is thus desired. In this research, bioprospecting of isolates from the less explored class Agaricomycetes was undertaken for l-asparaginase production. Plate assay (using phenol red and bromothymol blue dyes) was performed followed by estimation of l-asparaginase, l-glutaminase and urease activities by Nesslerization reaction for all the isolates. The isolate displaying the desired enzyme production was subjected to morphological, molecular identification, and phylogenetic analysis with statistical validation using Jukes-Cantor by Neighbour-joining tree of Maximum Likelihood statistical method. Among the isolates, Ganoderma aust...

Development of nanotechnologies to improve the functionality of natural antimicrobials for food applications has received much attention in recent years. Mesoporous silica particles, such as MCM-41, have been recently proposed as smart delivery devices capable of loading and releasing large amounts of cargo. In this study, the antimicrobial activity of caprylic acid entrapped in MCM-41 nanoparticles against Escherichia coli, Salmonella enterica, Staphylococcus aureus and Listeria monocytogenes was tested and compared with the bactericidal effect of free caprylic acid using the macrodilution method. The minimum bactericidal concentration for free caprylic acid was established to be below 18.5 mM for Staphylococcus aureus and Listeria monocytogenes and within the 18.5-20 mM range for Escherichia coli and Salmonella enterica. Moreover, caprylic acid-loaded nanoparticles showed a total inhibition of the growth within the 18.5-20 mM range for the tested bacteria, and therefore the antimicrobial activity was preserved. Transmission electron microscopy images revealed that bacteria treatment with the caprylic acid-loaded nanoparticles generated disruption of cell envelope and leakage of cytoplasmic content, which resulted in cell death. We believe that caprylic acid encapsulation in nanoparticles MCM-41 can provide an effective system for potential applications in food safety in the food industry due to the possible controlled release of fatty acid and the masking of its unpleasant organoleptic properties.

L-Asparaginase (L-asparagine aminohydrolase, E.C. 3.5.1.1) has been proven to be competent in treating Acute Lymphoblastic Leukaemia (ALL), which is widely observed in paediatric and adult groups. Currently, clinical L-Asparaginase formulations are derived from bacterial sources such as Escherichia coli and Erwinia chrysanthemi. these formulations when administered to ALL patients lead to several immunological and hypersensitive reactions. Hence, additional purification steps are required to remove toxicity induced by the amalgamation of other enzymes like glutaminase and urease. production of L-Asparaginase that is free of glutaminase and urease is a major area of research. In this paper, we report the screening and isolation of fungal species collected from the soil and mosses in the schirmacher Hills, Dronning Maud Land, Antarctica, that produce L-Asparaginase free of glutaminase and urease. A total of 55 isolates were obtained from 33 environmental samples that were tested by conventional plate techniques using Phenol red and Bromothymol blue as indicators. Among the isolated fungi, 30 isolates showed L-Asparaginase free of glutaminase and urease. The L-Asparaginase producing strain Trichosporon asahii IBBLA1, which showed the highest zone index, was then optimized with a Taguchi design. Optimum enzyme activity of 20.57 U mL −1 was obtained at a temperature of 30 °C and pH of 7.0 after 60 hours. Our work suggests that isolation of fungi from extreme environments such as Antarctica may lead to an important advancement in therapeutic applications with fewer side effects. Acute Lymphoblastic Leukaemia (ALL) is the most common type of childhood cancer. One of the major methods to treat ALL is through the enzyme L-Asparaginase. L-Asparaginase diminishes the supply of asparagine to cancer cells, thereby leading to apoptosis and cell cycle arrest in the G1 phase 1,2. However, depletion of glutamine due to the dual glutaminase and L-Asparaginase activity may lead to pancreatitis, haemostasis abnormalities, central nervous system dysfunction and immunological reactions due to antibody production 3,4. Recent breakthroughs have made asparaginase treatment on children and young adults more feasible. The administration of this chemotherapeutic drug in adults over the age of 45 years has shown tolerance but at the cost of higher toxicity 5. Additionally, presence of urease activity has been detected in commercial preparations, which can also reduce the efficacy of ALL treatment 6. A detailed description of the effect of glutaminase and urease on the outcome of L-Asparaginase activity is given in supplementary data. Apart from medicinal applications, L-Asparaginase is also used in the food industry to prevent acrylamide formation at high temperatures, which otherwise has carcinogenic and neurotoxic implications 7,8. Currently, L-Asparaginase is industrially produced mainly from prokaryotic microbes such as Escherichia coli and Erwinia chrysanthemi. However, the concomitant presence of the activities of glutaminase and urease means that additional purification steps are required to remove these two enzymes and maintain drug efficacy 9,10. The presence of glutaminase destroys the necessary glutamine required for the growth of normal cells 11. Urease leads

l-Asparaginase is a therapeutically and industrially-competent enzyme, acting predominantly as an anti-neoplastic and anti-cancerous agent. The existing formulations of prokaryotic l-asparaginase are often toxic and contain l-glutaminase and urease residues, thereby increasing the purification steps. Production of l-glutaminase and urease free l-asparaginase is thus desired. In this research, bioprospecting of isolates from the less explored class Agaricomycetes was undertaken for l-asparaginase production. Plate assay (using phenol red and bromothymol blue dyes) was performed followed by estimation of l-asparaginase, l-glutaminase and urease activities by Nesslerization reaction for all the isolates. The isolate displaying the desired enzyme production was subjected to morphological, molecular identification, and phylogenetic analysis with statistical validation using Jukes-Cantor by Neighbour-joining tree of Maximum Likelihood statistical method. Among the isolates, Ganoderma aust...

Graphical abstract Nanoscale zero-valent iron particles were investigated as an antibacterial agent against two Gram-positive bacteria; Staphylococcus aureus NRRL B-313 (S. aureus), Bacillus subtilus NRC (B. subtilus), and two Gram-negative bacteria; Escherichia coli NRC B-3703 (E. coli), Pseudomonas aeruginosa NRC B-32 (Ps. aeruginosa). The characterization of synthesized nZVI particles was obtained by XRD, SEM, EDX, and TG analyses. The results demonstrated that the nZVI particles have a spherical shape, mean crystalline size of 44.43 nm, and exhibited a good chemical and thermal stability performance under different physical conditions. The bacterial suspensions were subjected to the treatment using nZVI particle suspensions with a concentration of 10 mg/mL. The minimum inhibitory concentration of nZVI particles was determined using the well diffusion assay method and found to be 15, 10, 10, and 5 mg for the following four strains; S. aureus, B. subtilus, E. coli, and Ps. aerugin...

l-Asparaginase is a therapeutically and industrially-competent enzyme, acting predominantly as an anti-neoplastic and anti-cancerous agent. The existing formulations of prokaryotic l-asparaginase are often toxic and contain l-glutaminase and urease residues, thereby increasing the purification steps. Production of l-glutaminase and urease free l-asparaginase is thus desired. In this research, bioprospecting of isolates from the less explored class Agaricomycetes was undertaken for l-asparaginase production. Plate assay (using phenol red and bromothymol blue dyes) was performed followed by estimation of l-asparaginase, l-glutaminase and urease activities by Nesslerization reaction for all the isolates. The isolate displaying the desired enzyme production was subjected to morphological, molecular identification, and phylogenetic analysis with statistical validation using Jukes-Cantor by Neighbour-joining tree of Maximum Likelihood statistical method. Among the isolates, Ganoderma aust...

Endophytic fungi exhibit a complex web of interactions with host plants and have been extensively studied over the last several years as prolific sources of new bioactive natural products. Fungal enzymes are one of them which are used in food, beverages, confectionaries, textiles and leather industries to simplify the processing of raw materials. They are often more stable than enzymes derived from other sources. Enzymes of the endophytes are degraders of the polysaccharides available in the host plants. The use of simpler solid media permits the rapid screening of large populations of fungi for the presence or absence of specific enzymes. Fifty fungal strains, isolated from medicinal plants (Alpinia calcarata, Bixa orellana, Calophyllum inophyllum, and Catharanthus roseus) were screened for extracellular enzymes such as amylase, cellulase, laccase, lipase, pectinase and protease on solid media. Sixty four percent of fungi screened for enzymes showed positive for lipase, 62% for amy...

Endophytic fungi exhibit a complex web of interactions with host plants and have been extensively studied over the last several years as prolific sources of new bioactive natural products. Fungal enzymes are one of them which are used in food, beverages, confectionaries, textiles and leather industries to simplify the processing of raw materials. They are often more stable than enzymes derived from other sources. Enzymes of the endophytes are degraders of the polysaccharides available in the host plants. The use of simpler solid media permits the rapid screening of large populations of fungi for the presence or absence of specific enzymes. Fifty fungal strains, isolated from medicinal plants (Alpinia calcarata, Bixa orellana, Calophyllum inophyllum and Catharanthus roseus) were screened for extracellular enzymes such as amylase, cellulase, laccase, lipase, pectinase and protease on solid media. Sixty four percent of fungi screened for enzymes showed positive for lipase, 62% for amylase and pectinase, 50% showed for lipase, 32% showed for cellulase, 30% for laccase and only 28% showed positive for protease. The array of enzymes produced differs between fungi and often depends on the host and their ecological factors.

 Activated carbon is greatly used to adsorb toxic heavy metals from water bodies. Simultaneous removal of such pollutants and pathogenic impurities is essential for safe drinking water. In this study, silver nanoparticles (NPs) doped activated carbon (AC) composite was fabricated via hydrothermal technique and green synthesis technique using commercial activated carbon powder and silver nitrate solution. Several analytical techniques, including scanning electron microscopy (SEM), energy dispersive x-ray (EDX), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirmed the formation of silver nanoparticles on the surface and pores of AC. The prepared composite materials were accessed for their anti-bacterial property using Escherichia coli and Staphylococcus aureus and found that such materials have good antibacterial activity which shows that as fabricated composite can be used potentially for water treatment.

The present study provided a green approach for chitosan/silver nanocomposite (CS/AgNC) synthesis. CS/AgNC were synthesized by a biological method using the supernatant of Escherichia coli D8 (MF062579) strain in the presence of sun light. The absorbance spectra of particle solutions have been characterized by UV-Vis spectrophotometry, Fourier transform-infrared (FT-IR) spectroscopy and transmission electron microscopy (TEM). The obtained CS/AgNC showed absorption peak at 446 nm with an average particle size of ~21-31 nm. Moreover, CS/AgNC showed a potent antimicrobial activity against Candida albicans, Staphylococcus aureus and E. coli.

ILICA nanoparticles (SNPs) are particles of silica which are in the range of 1 to 100 nm in size. In the present study, native silica nanoparticles (SNPs) have been prepared chemically using cetyltrimethyl ammonium bromide (CTAB) and sodium silicate as precursors. The prepared native SNPs were organically modified using the trioctylphosphine oxide (Cyanex921) to yield the modified CY-SNPs particles. The synthesized SNPs and CY-SNPs were characterized by using Scanning Electron Microscope (SEM) micrographs that showed spherical particles with an average size of 35 nm. The elemental analysis was performed using the Energy Dispersive Spectrum (EDS). For the native SNPs, The peaks recorded around 1.9 Kv and 0.5 Kv are the binding energies corresponding to Si and O, respectively. For the modified CY-SNPs, an additional peak around 2.1 Kv corresponding to phosphorous from the cyanex921 moiety was observed. The powder X-Ray Diffraction (XRD) analysis of the material further confirmed the crystallinity of the SNPs as evidenced by the diffraction pattern at broad peak centered at 2ϴ=20o which indicates that the sample is amorphous. Fourier Transform Infra-Red Spectroscopy (FTIR) spectra indicated the loading of cyanex921 to the surface of the native SNPs. The antimicrobial activities of native and phosphine modified SNPs were assessed against Gram-positive and Gram-negative microorganisms using the minimum inhibitory concentration (MIC) studies. The results obtained showed that CY-SNPs have potential antibacterial effects against the gram positive microorganisms, viz. methicillin resistant staphylococcus aureus (MRSA) and the gram negative microorganisms viz. E.coli, klebsiella. Sp. and pseudomonas sp. and the MIC corresponding to each type has been determined. The native silica nanoparticles have not shown any antibacterial effect against the four bacteria strains previously mentioned over concentrations 0.10-5.0 mg/mL. The mechanism of the antibacterial activity of the proposed phosphine modified silica nanoparticles was discussed. The present study can generally approve the qualification of caynex921modified silica nanoparticles for the use as antibacterial agents.

Ο παθογόνος μικροοργανισμός Listeria monocytogenes είναι ένα βακτήριο που μολύνει τρόφιμα όπως αλεύρι, ζάχαρη, γαλακτοκομικά προιόντα και προκαλεί ασθένειες στον άνθρωπο όπως μηνιγγιοεγκεφαλίτιδα, βακτηριαιμία και λιστερίωση. Εμφανίστηκε πρώτη φορά στην Κίνα. Αναπτύσσεται κυρίως σε χαμηλές θερμοκρασίες. σε συνθήκες καταπόνησης και σε εφαρμογές χλωριούχου νατρίου. Το παθογόνο είναι ευάλωτο σε αντιβιοτικά όπως πενικιλίνη και αμπικιλίνη αλλά παρουσιάζει αντίσταση σε αντιβιοτικά όπως η τετρακυκλίνη, η χλωραμφενικόλη. Για την καταπολέμηση του παθογόνου γίνεται κάλυψη των τροφίμων με ζελατίνη και η χρήση γαλακτικού οξέος.

Amorpho-structural and magnetic analysis of Al2O3–P2O5–Na2O/NiO magnetic porous nanocomposites in the influence of SiO2 as a nucleating agent is studied. Concurrently, the effect of the incorporated NiO nanoparticles on the structural, morphological, optical, and magnetic characteristics of the Al2O3–P2O5–Na2O porous nanocomposites is examined. XRD and FT-IR spectroscopy indicated the successful formation of Al2O3–P2O5–Na2O crystallizes, while the incorporation of NiO/SiO2 increased the total crystalline degree. TEM-results designate an increase in particle size of the phosphate-based crystallites as the NiO/SiO2 level increases, which corresponded to the higher crystallization in the sodium aluminophosphate (Al4Na7P9O32) nanocomposite. The FT-IR results showed that these modified sol-gel reactions are a result of acid hydrolysis of the Al–O–P and Na–O–P bonds and the influence of Si–O–OH, leading to network termination by POH groups and octahedrally solvated Al atoms (with strong quadrupole interaction) with the SiOH groups. With the introduction of NiO/SiO2, the fundamental band gaps are found to be 3.89, 3.93, 3.98, and 4.05 eV for direct allowed transitions. In the case of the indirect transition, the energy of the bandgap were 3.42, 3.57, 3.63, and 4.75 with the introducing of NiO/SiO2. The saturation magnetization increased from 0.11 to 0.38 with increasing NiO content from 0.15 to 0.25%. Also, the switching field distribution (SFD) was investigated. The obtained optical and magnetic properties for Al2O3–P2O5–Na2O/NiO magnetic porous nanocomposites supported with silica which make them an excellent candidate for high-performance optics, biocompatible systems, solid-state electrolytes, fast ion-conducting materials, and opto-magnetic devices.

We used a green sol-gel synthesis method to fabricate a novel nanoporous copper aluminosilicate (CAS) material. Nanoporous CAS was characterized using X-ray powder diffraction (XRD), field emission transmission and scanning electron microscopies (FE-TEM/FE-SEM), Fourier transform infrared (FTIR) spectroscopy, and optical analyses. The CAS was also evaluated for use as a promising disinfectant for the inactivation of waterborne pathogens. The antimicrobial action and minimum inhibitory concentration (MIC) of this CAS disinfectant were determined against eight microorganisms (Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Candida albicans, and Aspergillus niger). An antimicrobial susceptibility testing of CAS was measured. Results of disc diffusion method pointed out that the diameters of the zone using well diffusion were wider than disc diffusion methods, and the findings also showed that the MIC of the CAS disinfectant against E. coli, S. enterica, and P. aeruginosa was 100 mg/L within 20 min of contact time. Meanwhile, the MIC of the CAS disinfectant was 100 mg/L within 40 min of contact time for the other strains. The efficacy of antimicrobial action (100%) reached within 20 to 40 min against all tested microbes. Herein, the antimicrobial susceptibility testing of CAS disinfectant showed no toxicity for human and bacterial cells. It can be concluded that nanoporous CAS is a promising, economically, and worthy weapon for water disinfection.

Extracellular enzymes or exoenzymes are synthesized inside the cell and then secreted outside the cell, where their function is to break down complex macromolecules into smaller units to be taken up by the cell for growth and assimilation. These enzymes degrade complex organic matter such as cellulose and hemicellulose into simple sugars that enzyme-producing organisms use as a source of carbon, energy, and nutrients. Grouped as hydrolases, lyases, oxidoreductases and transferases, these extracellular enzymes control soil enzyme activity through efficient degradation of biopolymers. In their review we are focusing on fungal enzymes and their abilities to degrade polymers to protect environment.