Laccase immobilization on bacterial cellulose produced in a mulberry pomace waste extract medium: Characterization and use for dye decolorization
Fevziye Unlu, Filiz Boran, Özfer Yeşilada, Süleyman Köytepe
Abstract
Abstract The present study aimed to immobilize laccase on dry bacterial cellulose (BC) produced by Komagataeibacter xylinus B759 in mulberry pomace waste extract as a low‐cost and natural waste by‐product and to determine the effectiveness of the obtained laccase immobilized BC (Lac/BC) for textile dye decolorization. The highest BC yield obtained after optimization studies was as 1.70 g/L in pH 8.0 medium at 32°C after 15 days. BC and Lac/BC structures were characterized by different instrumental techniques. A transition to more amorphous character was observed with the binding of the enzyme structure. The morphological properties and fiber structure of the BC and enzyme‐linked cellulose structures were examined by SEM and AFM analyses. Obtained Lac/BC pieces were used for the decolorization of Reactive Blue 171 (RB 171) and Reactive Blue 198 (RB 198) diazo dyes during the repeated‐batch process. As a result of using 12 pieces of Lac/BC, 93% and 98% decolorization values were obtained for the RB 171 and RB 198 dyes in the first use, while the color removal was still 83% and 51% at the 8th use, respectively. The results showed that BC produced in a mulberry pomace waste extract can be used for laccase immobilization and Lac/BC is an effective and promising system for textile dye decolorization.