Laccase immobilization on nanoporous aluminum oxide for black liquor treatment

FLORENCIA ALEJANDRA BRUERA; GUSTAVO RAÍL KRAMER; JUAN ERNESTO VELÁZQUEZ; MARCELA ALEJANDRA SADAÑOSKI; MARÍA ISABEL FONSECA; ALICIA ESTHER ARES; PEDRO DARÍO ZAPATA

Surfaces and Interfaces

Elsevier BV

Lugar: Melbourne; Año: 2022

2468-0230

Nanoporous aluminum oxide coating has been successfully synthesized using differentanodic synthesis conditions and self-assembled nanoporous with variable porediameter, thickness and porosity were obtained. The Anodic Aluminum Oxide (AAO)coatings exhibited appropriate morphological characteristics which were employed forthe Phebia brevispora BAFC 633 Laccase immobilization. Principal componentanalysis demonstrated that pH, contact time and enzyme concentration were the mainvariables which explain the total variation among the Laccase immobilization in thesamples. The highest enzymatic activity was reported in the sample synthesized to 0.3M of electrolyte concentration, 40 °C of temperature and 30 V of anodization voltage. Laccase specific activity of 4.1 Ucm-2 could be obtained using an enzymaticconcentration of 3.209 UL-1, pH 4.39 and contact time of 1.18 h according to theproposed regression model. Laccase/AAO bionanocatalyst can be easily collected andreserved 95.6% of initial activity after four cycles tests and immobilization yield ofaround 18.1%. Application of the immobilized Laccase for Black Liquor removal wasalso investigated. The bionanocatalyst showed better pH stability, 40% higher BLremoval efficiency compared to free laccase after 40 min of reaction, and the ability tobe collected and used up to twice for BL treatment. The novelty of this workcontemplates the development of a bionanocatalyst from a nanoporous coating and immobilized Laccases that can be successfully applied for the treatment of effluents contaminated with black liquor.