Phytochemically stabilized chitosan encapsulated Cu and Ag nanocomposites to remove cefuroxime axetil and pathogens from the environment

Green synthesis of chitosan-encapsulated CuO nanocomposites for efficient degradation of cephalosporin antibiotics in contaminated water

The synthesis and characterization of chitosan encapsulated copper oxide nanocomposites (CuNPs) using plant extracts for the photocatalytic degradation of second-generation antibiotics, cefixime and cefuroxime, were investigated. The study revealed that the presence of diverse chemical components in the plant extract significantly influenced the size of the CuNPs, with transmission electron microscopy (TEM) showing spherical shapes and sizes ranging from 11-35 nm. The encapsulation process was confirmed by an increase in size for certain samples, indicating successful encapsulation. X-ray photoelectron spectroscopy (XPS) analysis further elucidated the chemical makeup, confirming the valency state of Cu2+ and the presence of Cu-O bonding, with no contaminants detected. Photocatalytic activity assessments demonstrated that the copper oxide nanocomposites exhibited significant degradation capabilities against both antibiotics under UV light irradiation, with encapsulated nanocomposites (EnCu30) showing up to 96.18% degradation of cefuroxime within 60 min. The study highlighted the influence of chitosan encapsulation on enhancing photocatalytic performance, attributed to its high adsorption capability. Recycling studies confirmed the sustainability of the Cu nanocomposites, maintaining over 89% degradation rate after five consecutive cycles. This research underscores the potential of green-synthesized CuNPs as efficient, stable photocatalysts for the degradation of harmful antibiotics, contributing to environmental sustainability and public health protection.

Safe and sustainable food packaging: Argemone albiflora mediated green synthesized silver-carrageenan nanocomposite films

Silver-Carrageenan (Ag/Carr) nanocomposite film for food packing application by the green method using Argemone albiflora leaf extract has been developed in this study. Different plant parts of Argemone albiflora (blue stem prickly poppy) are used all over the world for the treatment of microbial infections, jaundice, skin diseases etc. GC-MS analysis was used to examine the phytochemical found in the Argemone albiflora leaf extract which reduces the metal ions to nanoscale. The biopolymer employed in the synthesis of nanocomposite film was carrageenan, a natural carbohydrate (polysaccharide) extracted from edible red seaweeds. We developed a food packing that is biodegradable, eco-friendly, economical and free from harmful chemicals. These films possess better UV barrier and mechanical and antimicrobial properties with 1 mM AgNO3 solution. The presence of silver nanoparticles in the carrageenan matrix was evident from FESEM. The mechanical properties were analysed by a Universal testing machine (UTM) and different properties like water vapour permeability (WVP), moisture content (MC) and total soluble matter (TSM) important for food packing applications were also analysed. The antimicrobial properties of the synthesized film samples were studied against E. coli and S. aureus pathogenic bacteria. These films were employed for the storage of cottage cheese (dairy product) and strawberries (fruit). This packing increased the shelf life of the packed food effectively. Ag/Carr films are biodegradable within four weeks.

Bio-based matrix photocatalysts for photodegradation of antibiotics

Antibiotics development during the last century permitted unprecedent medical advances. However, it is undeniable that there has been an abuse and misuse of antimicrobials in medicine and cosmetics, food production and food processing, in the last decades. The pay toll for human development and consumism is the emergence of extended antimicrobial resistance and omnipresent contamination of the biosphere. The One Health concept recognizes the interconnection of human, environmental and animal health, being impossible alter one without affecting the others. In this context, antibiotic decontamination from water-sources is of upmost importance, with new and more efficient strategies needed. In this framework, light-driven antibiotic degradation has gained interest in the last few years, strongly relying in semiconductor photocatalysts. To improve the semiconductor properties (i.e., efficiency, recovery, bandgap width, dispersibility, wavelength excitation, etc.), bio-based supporting material as photocatalysts matrices have been thoroughly studied, exploring synergetic effects as operating parameters that could improve the photodegradation of antibiotics. The present work describes some of the most relevant advances of the last 5 years on photodegradation of antibiotics and other antimicrobial molecules. It presents the conjugation of semiconductor photocatalysts to different organic scaffolds (biochar and biopolymers), then to describe hybrid systems based on g-C3N4 and finally addressing the emerging use of organic photocatalysts. These systems were developed for the degradation of several antibiotics and antimicrobials, and tested under different conditions, which are analyzed and thoroughly discussed along the work.

Evaluation of heavy metal removal and antibiofilm efficiency of biologically synthesized chitosan- silver Nano-bio composite by a soil actinobacterium Glutamicibacter uratoxydans VRAK 24

Biological synthesis of nanoparticles is cost-effective as well as safer than physical and chemical methods. This study focuses on the biological synthesis of silver nanoparticles using Glutamicibacter uratoxydans which remains still unexplored. The synthesized silver nanoparticles are encapsulated with chitosan to prepare nanobiocomposite. Actinobacteria were isolated from mesophilic soil and screened for heavy metal resistance. The potent heavy metal resistant isolate was identified by 16SrRNA sequencing and used for the biological synthesis of silver particles. The characterization of chitosan- silver nano-bio composite was carried out by UV-Vis spectroscopy, FTIR spectroscopy, and XRD. Morphology was analyzed by scanning electron microscopy. The particle size and stability were studied using Dynamic light scattering and Zeta potential analysis. The nano-bio composite was tested for lead removal efficiency and antibiofilm activity. The potent isolate was identified as Glutamicibacter uratoxydans and it was named as Glutamicibacter uratoxydans VRAK 24. The UV spectra showed maximum absorbance at 410 nm. The FTIR spectra and XRD confirmed chitosan encapsulation with silver nanoparticle. The size of nanobiocomposite was found to be 0.376. The stability of nanobiocomposite recorded a zeta potential value of -5.37 mV. The lead removal efficiency was found to be 87.69 %. In addition, the nanobiocomposite exhibited highest anti-biofilm activity against S.aureus when compared to E.coli. The research findings, concluded that the synthesized nanobiocomposite showed better anti-biofilm activity. Also, nanobiocomposite was found to be a good adsorbent for the removal of heavy metal lead.

Enhancing wheat crop production with eco-friendly chitosan encapsulated nickel oxide nanocomposites: A safe and sustainable solution for higher yield

In this work, we looked at using nickel oxide (NiO) nanocomposites with chitosan encapsulation as a nano-primer to improve wheat crop output. A straightforward green precipitation procedure was used to create the nanocomposites, and they were then characterized using several methods. According to the findings, the chitosan-encapsulated NiO nanocomposites possessed a large surface area and were resilient to changes in pH. Following this, wheat seeds were primed with the nanocomposites, and under greenhouse circumstances, the impact on crop growth was assessed. The findings demonstrated that, in comparison to the control group, nanocomposites priming considerably enhanced wheat growth and germination rate up to 99 %. In comparison to untreated plants, the wheat plants treated with the nanocomposites primer had greater plant height i.e. shoot length (11.4 cm) and root length (10.3 cm), leaf area, and biomass accumulation. Further research into the mechanism underlying the priming effect of nanocomposites on wheat growth revealed that the nanocomposites enhanced nutrient absorption, photosynthesis, and stress tolerance in wheat plants. In conclusion, our research shows that chitosan-encapsulated NiO nanocomposites have the potential to improve wheat crop productivity in an environmentally benign and long-term manner, offering a viable strategy for sustainable farming.

Removal of organic and inorganic effluents from wastewater by using degradation and adsorption properties of transition metal-doped nickel ferrite

Removal of water pollutants (methylene blue dye and heavy metals) was achieved by zinc/manganese-doped nickel ferrites (Ni_{1 - x}M_xFe₂O₄, where x = 0.00, 0.025, 0.10). Degradation of dye was achieved under natural solar light illumination. Degradation studies of dye were conducted under different parameters such as contact time-80 min, dye's concentration-5 mg/L, pH-7, and dosage of ferrites-15 mg. The adsorption of dye was studied using non-linear kinetics models (pseudo-first-order and pseudo-second-order) and isotherm models (Langmuir and Freundlich). The adsorption of dye followed pseudo-first-order kinetics (R² = 0.99377) than second-order kinetics (R² = 0.98063) and Langmuir isotherm model (R² = 0.96095) than Freundlich model (R² = 0.95962) with maximum adsorption efficiency of 29.62 mg/g. Doping of nickel ferrites caused an increase in the removal percentage of methylene blue dye (80 to 90%) and inorganic effluents (75 to 95% for lead and 47 to 82% for cadmium). In addition to this, band gap energy (2.43 to 3.26 eV) (UV-Vis spectroscopy), pore radius (65.2 to 74.8 A°), and specific surface area (16.45 to 27.95 m²/g) (BET analysis) were also increased. Generally, the results of the study revealed that synthesized nanoparticles can act as potential candidate for the removal of effluents from wastewater under optimum parameters along with recyclability, reusability, and separation under the influence of a magnetic field.

Influence of Bacillus subtilis strain Z-14 on microbial communities of wheat rhizospheric soil infested with Gaeumannomyces graminis var. tritici

Wheat take-all disease caused by Gaeumannomyces graminis var. tritici (Ggt) spreads rapidly and is highly destructive, causing severe reductions in wheat yield. Bacillus subtilis strain Z-14 that significantly controlled wheat take-all disease effectively colonized the roots of wheat seedlings. Z-14 increased the metabolic activity and carbon source utilization of rhizospheric microorganisms, thus elevating average well-color development (AWCD) values and functional diversity indexes of soil microbial communities. Z-14 increased the abundance of Bacillus in the rhizosphere, which was positively correlated with AWCD and functional diversity indexes. The Z-14-treated samples acquired more linkages and relative connections between bacterial communities according to co-occurrence network analyses. After the application of Ggt, the number of linkages between fungal communities increased but later decreased, whereas Z-14 increased such interactions. Whole-genome sequencing uncovered 113 functional genes related to Z-14’s colonization ability and 10 secondary metabolite gene clusters in the strain, of which nine substances have antimicrobial activity. This study clarifies how bacterial agents like Z-14 act against phytopathogenic fungi and lays a foundation for the effective application of biocontrol agents.