Nouaa Safa, Aziam Rachid, Carja Gabriela, Chiban Mohamed, Froidevaux Renato
Laboratory of Applied Chemistry and Environment, Faculty of Science, Ibn Zohr University, Agadir, Morocco; Univ. Lille, INRA, ISA, Univ. Artois, Univ. Littoral Côte d'Opale, EA 7394, ICV - Institut Charles Viollette, F-59000 Lille, France.
Laboratory of Applied Chemistry and Environment, Faculty of Science, Ibn Zohr University, Agadir, Morocco.
Int J Biol Macromol. 2025 Apr;303:140577. doi: 10.1016/j.ijbiomac.2025.140577. Epub 2025 Feb 2.
Laccase is an oxido-reductase known for its applications in biomass valorization (lignin depolymerization), in fine chemicals (building-blocks synthesis) or in environment (wastewater treatment). It works with molecular oxygen and produces water as its only by-product. However, its practical use remains limited due to the low stability and poor reusability of free laccase. To overcome these challenges, laccase from Trametes versicolor was immobilized onto layered double hydroxide and alginate composite beads by a glutaraldehyde cross-linker to create an easily separable and stable enzyme. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD) and energy-dispersive X-ray spectroscopy (EDX) were used to characterize the as-synthesized composite beads (laccase@MgFe(LDH)/alginate). The activity of the immobilized laccase was measured with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) model substrate. Here, the optimal conditions of laccase immobilization were explored and the effects of various conditions of immobilization, pH, storage stability and thermal resistance of the (laccase@MgFe(LDH)/alginate) were also studied. The results revealed that the optimal conditions for laccase immobilization were a concentration of glutaraldehyde of 2.5 %, an amount of laccase (0.5 U/mg) of 2 mg/mL, and an immobilization time of 6 h. The stability of (laccase@MgFe(LDH)/alginate) was >70 % of its initial activity, even after 10 cycles. The study of dye decolorization showed up to 74 % of methylene blue (MB) and 69 % of Crystal violet (CV) degradation, suggesting the use of immobilized laccase on MgFe(LDH)/alginate composite beads as a promising and environmentally friendly tool for the degradation of environmental pollutants, in particular for the removal of textile dyes from wastewater.
漆酶是一种氧化还原酶，因其在生物质增值（木质素解聚）、精细化学品（构建块合成）或环境（废水处理）中的应用而闻名。它以分子氧为作用底物，仅产生水作为副产物。然而，由于游离漆酶稳定性低且可重复使用性差，其实际应用仍然有限。为了克服这些挑战，通过戊二醛交联剂将云芝漆酶固定在层状双氢氧化物和藻酸盐复合珠上，以制备一种易于分离且稳定的酶。采用傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）、X射线衍射光谱（XRD）和能量色散X射线光谱（EDX）对合成的复合珠（漆酶@MgFe（LDH）/藻酸盐）进行表征。用2,2'-联氮-双-（3-乙基苯并噻唑啉-6-磺酸）（ABTS）模型底物测定固定化漆酶的活性。在此，探索了漆酶固定化的最佳条件，并研究了各种固定化条件、pH值、储存稳定性和（漆酶@MgFe（LDH）/藻酸盐）的耐热性的影响。结果表明，漆酶固定化的最佳条件是戊二醛浓度为2.5%，漆酶量（0.5 U/mg）为2 mg/mL，固定化时间为6 h。即使经过10个循环，（漆酶@MgFe（LDH）/藻酸盐）的稳定性仍大于其初始活性的70%。染料脱色研究表明，亚甲基蓝（MB）降解率高达74%，结晶紫（CV）降解率高达69%，这表明在MgFe（LDH）/藻酸盐复合珠上固定化漆酶是一种有前途的、环境友好的工具，可用于降解环境污染物，特别是从废水中去除纺织染料。
