Biological treatment methods for the biodegradation of anthropogenic toxic pollutants are eco-friendly in nature and are powered by a variety of microbial enzymes. Green chemistry and enzymes play a crucial role in catalyzing the biodegradation of organic and inorganic pollutants including azo dyes; polyaromatic hydrocarbons; lead; organic cyanides; aromatic amines; mono-, di-, and polyphenols; polymers; and mercury. Laccases form a prospective group of multifunctional oxidoreductase enzymes with great potential for oxidizing different categories of organic and inorganic pollutants and their diversified functions, such as pigment formation, lignin degradation, and detoxification of industrial wastes including xenobiotics mainly from the pharmaceutical, paper textile, and petrochemical industries. Therefore, it is very important to study laccases as green and environmentally friendly alternatives for the degradation of xenobiotics. This review article will cover comprehensive information about the functions and properties of bacterial laccases for a deep understanding of their scope and applications for effective bioremediation of recalcitrant xenobiotics.
The green, cost-effective and sustainable synthesis of nanomaterials has been a key concern of scientists and researchers. In this view, MNPs were prepared using a sapota plant leaf extract and the surface of the magnetite nanoparticles was engineered with unsaturated fatty acids. The first report on the effect of unsaturation on the size and magnetic properties of magnetite nanoparticles (MNPs), prepared by the co-precipitation method, has been studied by coating surfactants on MNPs based on their unsaturation from zero to three (lauric acid, oleic acid, linoleic acid, linolenic acid). The size effect and magnetic properties of MNPs coated with a surfactant have been studied in comparison with uncoated magnetite nanoparticles. After the surface modification of the magnetite particle, it is necessary to check whether the magnetic property has been restored or not. Therefore, the magnetic property was studied. The presence of a surfactant on the surface of MNPs was confirmed by Fourier-transform infrared spectroscopy (FTIR), which was later confirmed by scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The atomic structure was studied by X-ray diffraction (XRD) and the size of uncoated and surfactant-coated MNPs was determined by transmission electron microscopy (TEM) and the Scherrer equation by following XRD data. The magnetization property was analyzed by a vibrating sample magnetometer (VSM) at 10, 100 and 300 K and both bared and surfactant-coated MNPs exhibited a superparamagnetic nature at room temperature. The saturation magnetization (Ms) study shows that MNPs coated with a surfactant have a lower saturation magnetization value in comparison to uncoated NPs, confirming surface layering. Because the magnetic fluid has been stabilized in the aqueous medium, the double-layer model is expected to prevail.
The green synthesis of nanoparticles is an emerging branch of nanotechnology in recent times, as it has numerous advantages such as sustainability, cost-effectiveness, biocompatibility, and eco-friendliness. In the present research work, the authors synthesized ZnO nanoparticles (ZnO NPs) by a green and eco-friendly method. The synthesized ZnO NPs were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and Fourier transform infrared (FTIR) spectroscopic techniques. The calculated average crystallite size of ZnO NPs was observed at 36.73 nm and FESEM images clearly showed the cylindrical shape of nanoparticles. The absorption peak at 531 cm−1 was observed in the FTIR spectrum of the ZnO NPs sample, which also supports the formation of the ZnO wurtzite structure. Finally, the synthesized ZnO NPs potential was analyzed for the remediation of malachite green from an aqueous solution. The ZnO NPs showed a desirable photocatalytic nature under LEDs irradiation.