Volume 238, Issue 5

Climate change is a universal issue and plastic trash is the major cause of global warming. The present study was specifically designed to address the escalating plastic waste problem, the biodegradation of low-density polyethylene (LDPE) bags was investigated over an 8-week period using liquid culture approach. Bacterial strain ( Pseudomonas putida ) capable of degrading LDPE was isolated from common plastic garbage dumping sites. The strain was identified after sequencing analysis, as P. putida was evaluated for its effectiveness in degrading LDPE. Various analytical techniques, including weight loss, SEM, FTIR and GC-MS were employed to assess the degradation process. Results revealed that bacterial strain achieved 0.0776 % degradation. SEM and FTIR confirmed surface and chemical changes, while GC MS identified degradation by products in comparison to the control (where no bacteria was used).

Agricultural waste upcycling is crucial in the context of climate change. Utilizing seven agricultural by-products as basal substrates, coconut meal ( Cocos nucifera ) emerged as the most efficient, supporting the highest extracellular lipase (triacyl glycerol acyl hydrolases) yield i.e., 5.27 ± 1.75 a  U mL −1 . This study explored the production of extracellular lipases through solid-state fermentation by using co-cultures of Aspergillus niger , wild and mutant strains. Optimization experiments revealed that 30 g of coconut meal resulted is optimal for supporting highest lipases activity of 6.16 ± 0.16 a  U mL −1 . Incubation at 30 °C, 1 mL inoculum size, and distilled water as a diluent further enhanced lipolytic activity. The study identified sucrose as the preferred carbon source, with 4 % concentration demonstrating the highest activity at 13.66 ± 0.33 a  U mL −1 . Supplementary sources like 1 % olive oil and nitrogen sources such as ammonium chloride and peptone significantly increased lipases production. Magnesium sulfate (0.25 %) among metal ions exhibited the highest lipolytic potential i.e., 19.98 ± 0.01 a  U mL −1 . The crude lipases displayed optimal activity at pH 5.0 and 30 °C, with positive effects observed for Fe 2+ , Ca 2+ , and Mg 2+ , while Co 2+ , Na + , and Hg 2+ had negative impacts on lipases activity. This research not only contributes to understanding the factors influencing lipase production and activity, but also serves as an agricultural waste upcycling technique.

This study utilizes density functional theory (DFT) to investigate the adsorption of iron oxide clusters on the surface of coronene nanocages. The study explores five different adsorption geometries (P 1 –P 5 ) using the B3PW91/6-311G (d, p) approach, comparing them to pure coronene. Electronic properties, including energy (hf), HOMO, LUMO, Fermi level, HOMO–LUMO gap, vertical ionization potential, electron affinity, chemical hardness, softness, and chemical potential, were analyzed compared to native coronene nanocages. The calculations revealed strong chemisorption in P1, attributed to significant charge transfer from coronene to the metal atom, resulting in altered positions of HOMOs and LUMOs and a reduced HOMO–LUMO gap ( E gap ). Across all geometries (P 1 –P 5 ), electronic densities in HOMOs were concentrated on iron oxides, while in LUMOs, the electronic cloud was distributed throughout the structure. The diffusion of d-electrons from iron contributed to a more diffuse structure and a lower HOMO–LUMO gap ( E gap ), indicating N-type conduction. Global indices demonstrated increased reactivity of iron oxide–adsorbed coronene nanocages compared to native, unbound coronene.

Different strategies can be employed to enhance and adjust the overall characteristics and potential applications of the nanomaterials. Herein, ZnO–SiO 2 , Mn/ZnO–SiO 2 and ZnO–SiO 2 /PVA based nanocomposites were synthesized by sol-gel and in-situ polymerization methods by taking the Zn(CH 3 COO)·2H 2 O as ZnO, TEOS as the SiO 2 and Mn(SO 4 ) 2 ·7H 2 O as the Mn precursors. The present study investigates various aspects of ZnO–SiO 2 , Mn/ZnO–SiO 2 , and ZnO–SiO 2 /PVA nanomaterials, including electronic transition, surface morphology, elemental composition, chemical structure elucidation, thermal stability, and phase changes. To accomplish this, several techniques were employed. All the results confirmed the formation of the synthesized composite materials. Moreover, the catalytic and photocatalytic activities of the synthesized composites were studied through the degradation of Methylene blue (MB) dye, etc. The results confirmed that the synthesized nanocomposites exhibited good catalytic and photocatalytic activities towards removal of methylene blue (MB) dye removal. Further, the catalytic/photocatalytic activity of ZnO–SiO 2 , Mn/ZnO–SiO 2 and ZnO–SiO 2 /PVA nanocomposites were also compared towards the removal of methylene blue (MB) dye and it was verified that the Mn/ZnO–SiO 2 nanocomposite show high photocatalytic activity among the three nanocomposites i.e., ZnO–SiO 2 , Mn/ZnO–SiO 2 and ZnO–SiO 2 /PVA with removal efficiencies of 81 %, 77 % and 77 %, after 6 h, 5 h and 9 h respectively, under UV light illumination. Moreover, the photodegradation mechanism was also studied and finally, the biological activities like antioxidant and antileishmanial were also studied and compared.

Inadequate wastewater treatment infrastructure is a substantial worldwide concern, with implications for both the environment and public health. Specifically, the discharge of industrial effluents containing organic pollutants such as dyes represents a significant challenge due to their hazardous characteristics. Among these dyes, Bromophenol Blue (BPB) and Malachite green (MG) are extensively utilized in the industrial sector, contributing to environmental deterioration. In the current study, ternary-magnetic-silicate–graphene oxide [Fe 3 O 4 @SiO 2 –GO] was synthesized using the co-precipitation method and applied for the treatment of wastewater containing BPB and MG dyes. The point of zero charge and surface area of the adsorbent was estimated to be 5.7 and 253.8 m 2  g −1 , respectively. Energy dispersive X-ray was performed and the presence of iron, silicon, carbon, and oxygen was confirmed. The XRD analysis of GO, Fe 3 O 4 , and ternary Fe 3 O 4 @SiO 2 –GO composites were also performed to confirm the crystallinity of the composite. The SEM analysis showed a rough morphology with sheet-like appearance. The ternary composite was then applied for the adsorption of BPB and MG dyes. The maximum adsorption capacity for BPB and MG was 97.35 mg/g and 92.63 mg/g at pH 3 and 5, respectively. The results of the kinetics analysis showed that the pseudo-second-order kinetics model best explained the adsorption data for MG dye while pseudo-first-order kinetics for the BPB dyes. While the data best fitted the Langmuir adsorption isotherm with R 2 values of 0.994 and 0.998 for BPB and MG, respectively. These results demonstrate that Fe 3 O 4 @SiO 2 –GO serves as a promising adsorbent for the efficient removal of Bromophenol Blue (BPB) and Malachite Green (MG) from environmental water samples. Additionally, this adsorbent is environmentally friendly and chemically benign, and it can be reused efficiently for up to five cycles.

Garlic (Allium sativum) exhibit well defined therapeutic properties due to presence of distinct bioactive compounds, specifically organosulphur compounds. Spectral analysis by UV–Vis and FT-IR confirmed interaction of different functional groups and free electrons with the electromagnetic waves showed presence of different bioactive compounds formulated silver nanoparticles (AgNPs) using diallyl sulphide (DAS) also done for aqueous garlic extract. Different assays performed for confirming the presence of antibacterial and anticancer properties of DAS-AgNPs and garlic extract. The minimum inhibitory concentration required to inhibit Gram negative ( Escherichia coli , V. cholera ) and Gram positive ( S. aureus, B. cereus ) were found lesser in DAS-AgNPs followed by garlic extract. Cytotoxicity effect confirmed by DAS-AgNPs and A. sativum towards HeLa cell line by MTT assay. The IC 50 values obtained for MTT assay were at 24.09 μg/ml in DAS-AgNPs and 129.22 μg/ml in garlic extract. Anticancer efficacy was found more potent in DAS-AgNPs as compared with aqueous garlic extract.

Several technologies are employed for the synthesis of silver nanoparticles, each synthesis technique has advantages and disadvantages, and the best technique relies on the application at hand, the required qualities of the nanoparticles, and the size of the product. But in this article green synthesis were followed. In this research, AgNPs were synthesized using Salvia Sclarea leaf extract in green synthetic routes. The synthesized nanoparticles were examined using UV–vis spectroscopy, powder XRD, SEM, and FT-IR. Here three different type of silver nanoparticles were biosynthesized, AgNPs-1, AgNPs-2, and AgNPs-3 (where composition of AgNO 3 and extract were 6:1, 10:1 and 14:1 respectively). The catalytic ability of AgNPs 1–3 was determine in the reduction of nitro-compounds into corresponding amines, where AgNPs-2 was found efficient reductive catalyst. Moreover, antibacterial activities were checked against both gram-positive ( Bacillus Suntilis ) and gram-negative bacteria ( Klebsiella pneumoniae ) . Upon increasing Ag contents antibacterial activities were found in increasing mode. Which open new era of knowledge for further consideration.

The study demonstrates the effective application of high-speed dispersion and bead mill dispermat systems in dispersing organic pigments, specifically phthalocyanine blue and green, in water with positive results. Particle size analysis reveals that formulations prepared using a bead mill with the selective surfactants such as Tween-80, SLS, Cocosulphosuccinate (CSPS) and Oleyl sulphosuccinate (OSPS) which exhibits a narrower range of particle size distribution compared to those prepared using high-speed dispersion (HSD). Phthalocyanine blue pigment concentrate formulation, the bead mill preparation using Tween-80 and CSPS surfactants resulted in a higher viscosity and color strength compared to HSD. In addition, the phthalocyanine green pigment concentrate formulation prepared using a bead mill with SLS surfactant showed higher color strength than the formulation prepared using HSD with SLS surfactant. Moreover, the comparative study reported the Nano CaCO 3 pigment concentrate formulation prepared using a bead mill with SLS surfactant displayed a narrow range of particle size distribution ranging from 0.31 to 0.56 nm, with an average particle size of 0.435 nm, compared to the formulation prepared using HSD. All these findings suggested bead mill dispermat system with specific surfactants can produce pigment dispersions with a narrower particle size distribution, higher color strength, and better viscosity compared to HSD which demonstrating its potential as a more efficient and effective method for pigment dispersion.