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Decomposition of dangerous organic contaminants under irradiation with sunlight by Zn2+ Me3+ (Me = Al/Ga) LDHs doped with Ga2O3 and In2O3 and their derived mixtures of mixed oxides.

Layered double hydroxides are known for over 150 years. The first discovered natural mineral with this structure was hydrotalcite [5], reported by Hochstetter in 1842, synthesized 100 years later by Feitknecht [6]. The structure of this compound is related to that of brucite in which part of Mg 2+ cations are replaced by Al3+. Carbonate anions are intercalated between the layers to maintain the electroneutrality of material. The presence of hydrotalcite in nature is reduced. For this reason, the synthesis of LDHs was

Abstractβ-galactosidase from Aspergillus oryzae was strongly immobilized on magnetic particles functionalized with amino groups. By simple incubation without any activating agents, electrostatic interactions between amino groups and enzymes allowed obtaining a strong linkage. The immobilization efficiency was studied with the quantification of amino groups of the particles and of immobilized β-galactosidase. Kinetic parameters, especially the maximal velocity Vmax and the affinity Km, were determined with two substrates, o-NPG and lactose, and compared with free enzyme values in order to evaluate the influence of our immobilization methodology on the kinetic behavior of the enzyme. Therefore, magnetic capacity of the functionalized particles allows recovering and reusing the support. Results show efficient immobilization of β-galactosidase (58 µg/mg of support), able to hydrolyze substrates during multiple cycles of use. Thus, magnetic particles functionalized with amino groups represent an attractive support for simple and efficient β-galactosidase immobilization process.