Laccase-loaded functionalized graphene oxide assemblies with improved biocatalytic properties and decolorization performance

Photothermal degradation of triphenylmethane dye wastewater by Fe3O4@C-laccase

The degradation of synthetic dye wastewater is important for green chemistry and cost-effectiveness. In this study, we developed Fe3O4@C-laccase (laccase immobilized on Fe3O4@C nanoparticles) for photothermal degradation of high concentration of triphenylmethane dye wastewater. The Fe3O4@C-laccase possessed superior pH and thermal stabilities, as well as excellent tolerance to organic solvents, inhibitors, and metal ions. Laccase activity assays revealed that the activity recovery was approximately 118.2 %. Furthermore, the Fe3O4@C-laccase presented rapid and sustainable photothermal degradation capabilities to triphenylmethane dye wastewater. The initial removal efficiencies of 400 mg/L malachite green (MG), 400 mg/L brilliant green (BG), 100 mg/L crystal violet (CV), and 600 mg/L mixed dye (MG:BG:CV = 1:1:1) wastewater were approximately 99.8 %, 99.9 %, 96.4 % and 99.2 % by 60 min treatment, respectively. After undergoing 10 batches of reuse, the photothermal degradation efficiencies of the triphenylmethane dye wastewater remained consistently high, at about 99.3 %, 97.4 %, 94.0 %, and 95.1 %, respectively. The excellent photothermal degradation properties indicate that the Fe3O4@C-laccase holds promise for addressing high concentration of textile wastewater in various applications.

Green synthesis of NiO NPs for metagenome-derived laccase stabilization: Detoxifying pollutants and wastes

Laccases play a crucial role in neutralizing environmental pollutants, including antibiotics and phenolic compounds, by converting them into less harmful substances via a unique oxidation process. This study introduces an environmentally sustainable remediation technique, utilizing NiO nanoparticles (NPs) synthesized through green chemistry to immobilize a metagenome-derived laccase, PersiLac1, enhancing its application in pollutant detoxification. Salvadora persica leaf extract was used for the synthesis of NiO nanoparticles, utilizing its phytochemical constituents as reducing and capping agents, followed by characterization through different analyses. Characterization of NiO nanoparticles revealed distinctive FTIR absorption peaks indicating the nanoparticulate structure, while FESEM showed structured NiO with robust interconnections and dimensionality of about 50nm, confirmed by EDX analysis to have a consistent distribution of Ni and O. The immobilized PersiLac1 demonstrated enhanced thermal stability, with 85.55 % activity at 80 °C and reduced enzyme leaching, retaining 67.93 % activity across 15 biocatalytic cycles. It efficiently reduced rice straw (RS) phenol by 67.97 % within 210 min and degraded 70-78 % of tetracycline (TC) across a wide pH range (4.0-8.0), showing superior performance over the free enzyme. Immobilized laccase achieved up to 71 % TC removal at 40-80 °C, significantly outperforming the free enzyme. Notably, 54 % efficiency was achieved at 500 mg/L TC by immobilized laccase at 120 min. This research showed the potential of green-synthesized NiO nanoparticles to effectively immobilize laccase, presenting an eco-friendly approach to purify pollutants such as phenols and antibiotics. The durability and reusability of the immobilized enzyme, coupled with its ability to reduce pollutants, indicates a viable method for cleaning the environment. Nonetheless, the production costs and scalability of NiO nanoparticles for widespread industrial applications pose significant challenges. Future studies should focus on implementation at an industrial level and examine a wider range of pollutants to fully leverage the environmental clean-up capabilities of this innovative technology.

Magnetic nanomaterials assisted nanobiocatalysis to abate groundwater pollution

Magnetic nanoparticles are of great interest for research as they have a wide range of applications in biotechnology, environmental science, and biomedicine. Magnetic nanoparticles are ideal for magnetic separation, improving catalysis's speed and reusability by immobilizing enzymes. Nanobiocatalysis allows the removal of persistent pollutants in a viable, cost-effective and eco-friendly manner, transforming several hazardous compounds in water into less toxic derivatives. Iron oxide and graphene oxide are the preferred materials used to confer nanomaterials their magnetic properties for this purpose as they pair well with enzymes due to their biocompatibility and functional properties. This review describes the most common synthesis methods for magnetic nanoparticles and their performance of nanobiocatalysis for the degradation of pollutants in water.•Magnetic nanomaterials have been synthesized for their application in nanobiocatalysis and treating groundwater.•The most used method for magnetic nanoparticle preparation is the co-precipitation technique.•Peroxidase and oxidase enzymes have great potential in the remotion of multiple contaminants from groundwater.