Bimetallic nanoparticles exhibit bifunctional or synergistic effects prevailing between two metals with the capabilities of enhanced electronic, catalytic, and optical properties. Green synthetic routes have gained tremendous interest because of the noninvolvement of toxic and harmful chemical reagents in preparation. Therefore, we develop bimetallic Ag-Cu nanoparticles (Ag-Cu NPs) through an eco-friendly and biocompatible preparation method. In this study, Ag-Cu NPs have been synthesized from leaf extracts of the commonly known sage, S. officinalis. The extract has a rich phytochemical composition, including bioreducing polyphenols, flavonoids, and capping/stabilizing agents. An array of well-known spectroscopic and microscopic techniques were used to characterize the as-prepared Ag-Cu bimetallic nanoparticles, including X-ray diffraction (XRD), ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The size of the Ag-Cu NPs was found to be 50 nm with a spherical shape and an almost uniform distribution. The antibacterial effect was further evaluated using agar well diffusion and disc diffusion assays. Ag-Cu NPs exhibit antibacterial and antibiofilm properties against Gram-positive and Gram-negative bacteria strains. The minimum inhibitory concentration (MIC) of Ag-Cu NPs was between 5 g/mL and 15 g/mL. The Ag-Cu NPs inhibit biofilm formation at 25 g/mL and 50 g/mL. The results of biogenic Ag-Cu NPs provide novel antibacterial activity against Gram-positive and Gram-negative bacteria, as well as antibiofilm activity. Hence, Ag-Cu NPs might serve as a novel antibacterial agent with potential antibacterial and antibiofilm properties.

Nanofiltration (NF) is a membrane-based filtration method that has gained prominence in modern technology because of its superior separation efficiency, cost-effectiveness, and ease of operation. With pore sizes ranging from 1 to 10 nm, and a molecular weight cut-off (MWCO) ranging from 100 to 2000 Da, NF membranes bridge the gap between reverse osmosis (RO) and ultrafiltration (UF) processes—and effectively removing a wide range of contaminants including suspended particles, oil emulsions, bacteria, cells, colloidal haze, viruses, macromolecules, proteins, sub-molecular organic groups, monovalent and divalent ions, and heavy metals. To enhance membrane selectivity and permeability, NF membranes have been fabricated from a variety of materials including polymer thin films, metals, polymers with inorganic nanofillers, carbon compounds, metal composites, and nano-semiconductors. Each of these materials contributes unique properties to NF membranes, such as high aspect ratios, biocompatibility, chemical resistance, and thermal stability, making them valuable in various separation processes. Despite the advancements in NF membrane materials, challenges such as membrane fouling and low permeate flux persist. This review provides an in-depth examination of NF as an innovative solution for wastewater treatment, focusing on its principles, applications, and recent advancements in NF technology. This highlights the challenges of current wastewater treatment methods and explores how NF offers a viable alternative for improving treatment efficiency and sustainability. This review also discusses the potential of integrating various membrane materials to optimize NF performance and outlines future trends and challenges in the widespread adoption of NF in wastewater management systems.

This study examined the effect of varying concentrations of Ocimum basilicum aqueous extract, which was done via the green synthesis of Silver nanoparticles (AgNPs), on the identification of the most effective concentration for bacteria inhibitory activity. Different concentrations of the aqueous Ocimum basilicum extract (0.25, 0.50, 0.75 and 1.00 mM) were used as reducing and stabilizing agent to synthesize AgNPs by means of the reduction method. The crystal structure and morphology of the NPs were characterized UV–Vis spectra, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The antibacterial efficacy of AgNPs was studied against E. coli ATCC 35218 using well diffusion, MIC, MBC, and time-kill curve. The dark yellow color of the Ocimum basilicum aqueous solution indicates the successful synthesis process of the AgNPs. UV-spectra of the AgNPs display a gradual increase of absorption in sequence with concentration increase of aqueous Ocimum basilicum extract solution from 0.25 to 1.00 mM. This, in turn, led to a shift in the wavelength from 488 to 497 nm, along with a change in the nanoparticle size from 52 to 8 nm. The tests also showed a high activity of the particles against bacteria (E. coli), ranging between 15.6 and 62.5 µg/ml. Based on AgNPs, it was confirmed that an aqueous Ocimum basilicum extract can be used as an effective, reducing and stabilizing agent for the synthesis of different sizes of AgNPs based on the solvent concentration. The AgNPs also proved to be effective in inhibiting and killing bacteria.

Our work was devoted to studying the effect of different concentrations of Mentha spicata aqueous extract on the green synthesis of silver nanoparticles (AgNPs) in order to obtain the most effective of these concentrations for bacteria inhibitory activity. Different concentrations of the aqueous M. spicata extract (0.25, 0.50, 0.75, and 1.00mM) were used as biological solvent to synthesize AgNPs by means of the reduction method. The crystal structure and morphology of the NPs were characterized UVvis spectra, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The inhibition effect of AgNPs on Escherichia coli was studied to determine the minimum inhibitory concentration (MIC). The dark yellow color of the M. spicata extract aqueous solution indicates the successful synthesis of the AgNPs. UV spectra of the NPs show a gradual increase in absorption with increasing concentration of aqueous M. spicata extract solution from 0.25 to 1.00mM, accompanied by a shift in the wavelength from 455 to 479nm along with a change in the nanoparticle size from 31 to 9nm. The tests also showed a high activity of the particles against bacteria (E. coli) ranging between 15.6 and 62.5µg/ml. From the AgNPs, it was confirmed that aqueous M. spicata extract is an effective biosolvent for the synthesis of different sizes of AgNPs according to the solvent concentration. The AgNPs also proved effectual for the killing of bacteria.

Sponges forms association with many bacteria that serve as sources of new bioactive compounds. The compounds are produced in response to environmental and nutritional conditions of the environment that enable them to protect their host from colonization. In this study, three sponge bacterial endophytes were isolated, identified, and subjected to solvent extraction processes. The identified bacteria are Bacillus amyloquifaciens, Bacillus paramycoides, and Enterobacter sp. The bacteria were cultured in two different fermentation media with varying nutritional composition for the extraction process. The extracts were evaluated for antibacterial and antibiofilm activity against microfouling bacteria and the chemical composition of each extract was analyzed via gas chromatography-mass spectrometry (GC-MS). The extract from the endophytes shows varying antibacterial and antibiofilm activity against the tested strains. Several compounds were detected from the extracts including some with known antibacterial/antibiofilm activity. The results showed variations in activity and secondary metabolite production between the extracts obtained under different nutritional composition of the media. In conclusion, this study indicated the role of nutrient composition in the activity and secondary metabolites production by bacteria associated with sponge Also, this study confirmed the role of sponge bacterial endophytes as producers of bioactive compounds with potential application as antifouling (AF) agents.

The biotechnological process called solid-state fermentation (SSF) was applied for hyper production of protease by using a fungal strain called Aspergillus oryzae. From screening of 9 different local substrates (peanut shell, wheat bran, guava leaves, sugar cane bagasse, rice polish, wheat straw, corn straw, reed grass, and rice straw), peanut shells serve as the best substrates for protease production under optimized cultured conditions. The varying physiochemical parameters such as pH (2-9.5), temperature (30-52 °C), incubation time (1-10 days), inoculum size (1-8 mL), moisture level (20-125%), and substrate concentration (1-7 g) were optimized by response surface methodology (RSM). The highest activity of protease was recorded to be 1101.778 U/mL at 660 nm using peanut shell was optimum at pH 8, temperature 52 °C, incubation time 8 days, inoculum size 2 mL, moisture level 20%, and substrate concentration 2 g. The crude form of enzymes produced were further purified through ammonium sulfate precipitation, dialysis, and gel filtration chromatography. Then, purified enzymes were characterized at different pH, temperature, and incubation time. For characterization of purified protease, pH, temperature, and incubation time were 8, 52 °C, and 8 days for peanut shell and was done by one factor at a time method. Hence, isolated enzymes were alkaline in nature, i.e., alkaline proteases. Then, protease produced from peanut shells was applied to locally available detergents to increase their catalytic activity for strain removal. At last, the final results were interpreted in the form of 3D surface and contour plots using Microsoft Excel 2013 and Minitab 17 software. In conclusion, the utilization of A. oryzae and peanut shell as the substrate in the biotechnological process of SSF demonstrated successful hyper production of alkaline protease. The optimized conditions resulted in high enzyme activity and showcased the potential application of the isolated enzymes in improving the catalytic activity of locally available detergents.