In the study, Poly Vinyl Alcohol (PVA) films engineered with the nanoparticles and essential oils have been developed as efficient alternative to the currently used food packaging materials. For ...this, impact of cinnamon essential oil (CEO), on the metabolomic profile of Staphylococcus aureus, Escherichia coli and Aspergillus flavus was analysed. Subsequently, PVA based nanocomposite films CEO, zinc oxide nanoparticles (ZnONPs), and nanocellulose (NC) were synthesised and characterized by FT-IR analysis. By the GC–MS analysis. The presence of ZnONPs enhanced the release of cinnamaldehyde from 31.16 to 44.23 and further enhancement to 71.82 was seen the presence of nanocellulose. The incorporation of NPs was found to enhance the hydrodynamic and mechanical properties of the prepared films. The final developed films, PZNCCEO, showed the least values for WHC and MC which were 56.31 ± 2.12 % and 13.30 ± 0 % respectively. Antimicrobial efficacy could also be demonstrated through the observation on changes in the morphological features of treated S. aureus and E. coli by the FE-SEM. Finally, the developed nanocomposite film was found to have the potential for food packaging as demonstrated through the protection of corn kernals and Vigna unguiculata.
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Lactobacillus plantarum can produce many secondary metabolites, some of which have antibacterial effects. This study aimed to explore the main antimicrobial metabolites of ...Lactobacillus plantarum LPZN19.
The results of antibacterial activity after fermentation for different durations showed that the metabolites from the LPZN19 cell-free supernatant (LCFS) after 24 h had the strongest antibacterial activity, which was confirmed by the highest contents of organic acids and fatty acids in the LCFS after 24 h. Lactic acid, phenyllactic acid, malic acid, aspartic acid, dodecanoic acid and propionic acid were the main differentially abundant metabolites. LCFS was separated by semi-preparative liquid chromatography to obtain 4 antibacterial parts, mainly organic acids such as lactic acid, glycolic acid, and citric acid, and fatty acids such as stearic acid, palmitic acid, and octanoic acid. In addition, fatty glycerides and amino acids with antimicrobial activity were included.
Our findings indicate that the main antimicrobial metabolites of L. plantarum LPZN19 include organic acids, fatty acids, fatty glycerides and some amino acids with antimicrobial activity, which not only clarifies the main antimicrobial metabolites of L. plantarum LPZN19 but also provides an effective method for rapid screening of antimicrobial substances.
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•The rGO-BixFe(1-x)2O3 (x = 0.02, 0.05, 0.10 and 0.20) nanocomposites are synthesized by a cost-effective co-precipitation procedure.•Presence of various defects have been realized in ...the sample from PL spectra.•The direct band gap of the nanocomposite with Bi loading upto 10 % is found to be 2.51 eV.•The nanocomposite with Bi loading upto 10 % may be suitable photocatalyst of choice towards the photodegradation of Crystal Violet.•Adsorption capacity and rate constant in the nanocomposite are found to be 28.50 mg/g and 0.0473 min−1 respectively.•The nanocompoiste showed antibacterial activity against Staphylococcus aureus (Gram +Ve) and Klebsiella pneumonia (Gram −Ve).
The nanocomposites of rGO-BixFe(1-x)2O3 (x=0.02, 0.05, 0.10 and 0.20) are successfully synthesized with the help of a cost-effective co-precipitation procedure. Influence of Bi on to the magnetic, optical, microstructural and antimicrobial properties of Fe2O3 are investigated. The presence of pure α-Fe2O3 is being witnessed through the characteristic intensity of XRD peak where phase impurity is not noticed up to 10 % of Bi loading. Presence of various defects have been realized in the sample from PL spectra. The direct band gap of the adsorbent nanocomposite with Bi loading up to 10 % with that of α-Fe2O3 is found to be 2.51 eV and it may be taken as a suitable photocatalyst of choice towards the photodegradation of Crystal Violet with 97.69 % by maintaining the pH-10 and time-60 min as optimum condition. Adsorption capacity (qm) and rate constant (kapp) are found to be 28.50 mg/g and 0.0473 min−1 respectively. The antimicrobial analysis of the synthesized material signifies its antibacterial activity against Staphylococcus aureus (Gram +Ve) and Klebsiella pneumonia (Gram −Ve). On the basis of our finding, the synthesized nano composite may be the materials of choice for the optical device application, memory storage device as well as in the biomedical application.
The study evaluates caesium, potassium, silver, and zinc tungstophosphates synthesized in bulk and Y zeolite-supported forms through a two-step process. Spectral investigation reveals the impact of ...cation size on tungstophosphates formation. The large cations form ion-ion interaction with the Keggin ion, while smaller cations form hydrogen bonds between the cation hydration sphere and terminal oxygens in the Keggin ion. Supported salts formation proceeds without Keggin ion distortion. Zeta potential showed the absence of particle aggregation for caesium and potassium tungstophosphate. Nicosulfuron removal by the supported salt exhibits enhanced retention, with the exception observed for zinc tungstophosphate suggesting a decomposition mechanism. Antimicrobial evaluations reveal silver salt's potency, especially in zeolite-supported form, emphasizing the role of zeolite support. In the presence of pesticide molecules, the antimicrobial activity of salts lowers, with the exception seen for fungus strain. The antioxidant assessments demonstrate superior inhibition for insoluble bulk salts, with caesium tungstophosphate exhibiting the highest inhibition, while supported silver salt enhances bulk salt performance. The presence of pesticides affects both antimicrobial and antioxidant activities, while a complex relationship with radical scavenging ability in bulk and supported salts is independent of their pesticide adsorption capacities. The study broadens the range of the versatile applications of tungstophosphates, highlighting their specific interactions with pesticides and their impact on bioactivity and environmental remediation.
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•Cs, K, Ag, and Zn-tungstophosphate synthesized in bulk and Y zeolite-supported forms.•Ion-ion interaction and hydrogen bonds with Keggin ion are influenced by cation size.•Nicosulfuron removal by the supported salts is enhanced compared to bulk forms.•Potent antimicrobial activity of silver salt, especially in zeolite-supported form.•Significant influence of nicosulfuron on antimicrobial and antioxidant activities.
To degrade anthracene, magnetite nanoparticles were produced using a simple co-precipitation process. The fabricated nanoparticles have been analyzed for structural and optical properties. XRD ...examination revealed that the produced Fe3O4 nanoparticles were cubic phase, having a mean crystallite dimension of 18.84 nm. DLS determined the hydrodynamic diameter of Fe3O4 nanoparticles to be 182 nm. UV-Vis research revealed that Fe3O4 nanoparticles absorb at 390 nm. A peak at 895 cm-1 in the FT-IR study indicated the metal-oxygen connection. The synthesized Fe3O4 nanoparticles demonstrated an effective photocatalytic performance towards anthracene degradation and was found to be 86.55%. Furthermore, Fe3O4 nanoparticles showed the highest antimicrobial activity against Bacillus subtilis was 19.43 mm. The present study is the first and foremost study determining the dual role of Fe3O4 nanoparticles towards bioremediation and biomedical applications.
Polycyclic aromatic hydrocarbons (PAHs) are omnipresent, persistent, and carcinogenic pollutants continuously released in the atmosphere due to the rapid increase in population and industrialization ...worldwide. Hence, there is an ultimate rise in concern about eliminating the toxic PAHs and their related aromatic hydrocarbons from the air, water, and soil environment by employing efficient removal technologies using nanoparticles as a catalyst. Here, the degradation of selective PAHs viz., anthracene and benzene using laboratory synthesized rGO-Ag-Cu-Ni nanocomposite (catalyst) was studied. Characterization studies revealed the nanocomposites exhibited surface plasma resonance at 350 - 450 nm, confirming the presence of Ag, Cu, and Ni metal ions embedded on the reduced graphene substrate. It was found that the nanocomposites synthesized were spherical, amorphous in nature, and aggregated together with measurements ranging from 423 to 477 nm. An SEM-EDX analysis of the nanocomposite demonstrated that it contained 25.13% O, 14.24% Ni, 27.79% Cu, and 32.84% Ag, which confirms the synthesis of the nanocomposite. Crystalline, sharp nanocomposites of average size 17–41 nm with an average diameter of 118.5 nm (X-ray diffraction and DLS) were observed. FTIR spectra showed that the nanocomposites had the functional groups alkanes, alkenes, alkynes, carboxylic acids, and halogen derivatives. Batch adsorption studies revealed that the maximum degradation achieved at optimum nano-composite concentration of 10 μg/mL, pH value of 5, PAHs concentration of 2 μg/mL and effective irradiation source being UV radiations in the case of both benzene and anthracene pollutants. The degradation of benzene and anthracene followed Freundlich & Langmuir isotherm with the highest R2 value of 0.9894 & 0.9885, respectively. Adsorption kinetic studies under optimum conditions revealed that the adsorption of both benzene and anthracene followed Pseudo-second order kinetics. Antimicrobial studies revealed that the synthesized nano-composite exhibited potential antimicrobial activity against Gram positive bacterium (Bacillus subtilis, Staphylococcus aureus), Gram negative bacterium (Klebsiella pneumonia, Escherichia coli) and fungal strain (Aspergillus niger) respectively. Thus, the synthesized rGO-Ag-Cu-Ni nano-composite acts as an effective antimicrobial agent as well as a PAHs degrading agent, helping to overcome antibiotics resistance and to mitigate the overgrowing PAHs pollution in the environment.
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•Synthesis of rGO-Ag-Cu-Ni nano-composite and its characterization using UV spectroscopy, FTIR, SEM-EDX, XRD and DLS analysis were conducted•Batch adsorption studies were conducted with various parameters viz, concentration of catalyst (rGO-Ag-Cu-Ni nano-composite).•Concentration of anthracene and benzene (pollutant), pH and irradiation source followed by Kinetic and isotherm adsorption studies.•Antimicrobial potential of synthesized nano-composite (rGO-Ag-Cu-Ni nano-composite) were examined.
Marine organisms, such as sea urchins like Heliocidaris crassispina, produce bioactive substances with antimicrobial activity to protect themselves from the high density of microorganisms in their ...habitats. One such substance, Echinochrome A (Ech A), has been isolated from various sea urchins' shells and spines using strong acidic solutions and organic solvents. Ech A, however, has not been reported from the coelomic fluid of H. crassispina. In this study, we report the antimicrobial activity of H. crassispina coelomic fluid extract against various microbes, evaluating its potential for purifying potent antimicrobial materials. Upon confirming the extract as a promising source of antimicrobial materials, we isolated antimicrobial compounds from the extract. A series of HPLC steps were taken to purify antimicrobial materials from the H. crassispina coelomic fluid extract, resulting in the isolation of two single absorbance peaks showing antimicrobial activity against Staphylococcus aureus. One peak consisted of a single antimicrobial compound with a molecular weight (MW) corresponding to Ech A, while the other peak comprised five MWs inferred to be those of Ech A and its oxidative products. The elution of Ech A in two separate peaks may be attributable to the presence of Ech A's isomer, as reported in several previous studies. The use of the environmentally friendly extraction method in procurement of Ech A from the coelomic fluid would contribute to the implementation of risk-reducing extraction method for researchers studying Ech A from sea urchins.
•This study is the first to report the presence of Ech A in the coelomic fluid of the sea urchin Heliocidaris crassispina.•Ech A was successfully isolated from the coelomic fluid of H. crassispina using a series of HPLC steps.•The purified Ech A exhibited antimicrobial activity against a variety of microbes, S.aureus, S.flexneri, and C.albicans were the most susceptible strains.•This study avoids use of strong solvents, employing a less hazardous and more environmentally friendly extraction method.
Recently, antibiotic resistance of pathogens has grown given the excessive and inappropriate usage of common antimicrobial agents. Hence, producing novel antimicrobial compounds is a necessity. ...Carbon nanomaterials (CNMs) such as carbon nanotubes, graphene/graphene oxide, and fullerenes, as an emerging class of novel materials, can exhibit a considerable antimicrobial activity, especially in the nanocomposite forms suitable for different fields including biomedical and food applications. These nanomaterials have attracted a great deal of interest due to their broad efficiency and novel features. The most important factor affecting the antimicrobial activity of CNMs is their size. Smaller particles with a higher surface to volume ratio can easily attach onto the microbial cells and affect their cell membrane integrity, metabolic procedures, and structural components. As these unique characteristics are found in CNMs, a wide range of possibilities have raised in terms of antimicrobial applications. This study aims to cover the antimicrobial activities of CNMs (both as individual forms and in nanocomposites) and comprehensively explain their mechanisms of action. The results of this review will present a broad perspective, summarizes the most remarkable findings, and provides an outlook regarding the antimicrobial properties of CNMs and their potential applications.
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•Carbon nanomaterials (CNMs) such as carbon nanotubes, graphene, and fullerenes, are an emerging class of novel materials.•CNMs can exhibit a considerable antimicrobial activity, especially in the nanocomposite forms.•The most important factor affecting the antimicrobial activity of CNMs is their size.•This study aims to cover the antimicrobial activities of CNMs (both as individual forms and in nanocomposites).
