Studies on the laccase-mediated decolorization, kinetic, and microtoxicity of some synthetic azo dyes.

Background: Enzymatic elimination of synthetic dyes, one of the most environmentally hazardous chemicals, has gained a great interest during the two last decades. The present study was performed to evaluate the decolorization and detoxification potential of the purified laccase of Paraconiothyrium variabile in both non-assisted and hydroxybenzotriazole-aided form against six azo dyes.

Results: The obtained results showed that Acid Orange 67, Disperse Yellow 79, Basic Yellow 28, Basic Red 18, Direct Yellow 107, and Direct Black 166 were decolorized up to 65.

Laccase-catalyzed decolorization and detoxification of Acid Blue 92: statistical optimization, microtoxicity, kinetics, and energetics.

Background: In recent years, enzymatic-assisted removal of hazardous dyes has been considered as an alternative and eco-friendly method compared to those of physicochemical techniques. The present study was designed in order to obtain the optimal condition for laccase-mediated (purified from the ascomycete Paraconiothyrium variabile) decolorization of Acid Blue 92; a monoazo dye, using response surface methodology (RSM). So, a D-optimal design with three variables, including pH, enzyme activity, and dye concentration, was applied to optimize the decolorization process.

Toxicity of nanomaterials; an undermined issue.

Nanomaterials are employed in extensive variety of commercial products such as electronic components, cosmetics, food, sports equipment, biomedical applications, and medicine. With the increasing utilization of engineered nanomaterials, the potential exposure of human to nanoparticles is rapidly increasing. Nowadays when new nanomaterials with new applications are introduced, mostly good and positive effects are mentioned whereas possible hazards arising from nanosize of the compounds are undermined.

Safety concerns to application of graphene compounds in pharmacy and medicine.

Graphene, the new allotrope of carbon is a single layer of monocrystalline graphite with sp2 hybridized carbon atoms. This compound has received worldwide attention due to its extraordinary physical and chemical properties. Duo to the widespread application of geraphenes, concerns are raising about its environmental safety or the safety protocols for handling and waste of graphene-based materials.

Immobilization of laccase in alginate-gelatin mixed gel and decolorization of synthetic dyes.

Alginate-gelatin mixed gel was applied to immobilized laccase for decolorization of some synthetic dyes including crystal violet. The immobilization procedure was accomplished by adding alginate to a gelatin solution containing the enzyme and the subsequent dropwise addition of the mixture into a stirred CaCl(2) solution. The obtained data showed that both immobilized and free enzymes acted optimally at 50°C for removal of crystal violet, but the entrapped enzyme showed higher thermal stability compared to the free enzyme.