Decolorization and detoxification of synthetic dye compounds by laccase immobilized in vault nanoparticles

Yifan Gao; Meng Wang; Kshitija Shah; Shashank Singh Kalra; Leonard H Rome; Shaily Mahendra

doi:10.1016/j.biortech.2022.127040

Decolorization and detoxification of synthetic dye compounds by laccase immobilized in vault nanoparticles

Bioresour Technol. 2022 May:351:127040. doi: 10.1016/j.biortech.2022.127040. Epub 2022 Mar 19.

Authors

Yifan Gao¹, Meng Wang², Kshitija Shah¹, Shashank Singh Kalra¹, Leonard H Rome³, Shaily Mahendra⁴

Affiliations

¹ Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, United States.
² Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, United States; Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA 15260, United States.
³ Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, United States; California NanoSystems Institute, University of California, Los Angeles, CA 90095, United States.
⁴ Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, United States; California NanoSystems Institute, University of California, Los Angeles, CA 90095, United States. Electronic address: mahendra@seas.ucla.edu.

PMID: 35318145
DOI: 10.1016/j.biortech.2022.127040

Abstract

This study presents an eco-friendly and efficient technology, using immobilized enzymes, vault-encapsulated laccases (vlaccase), for decolorization and detoxification of dyes. Vault encapsulation remarkably improved the performance of laccase at industrially relevant conditions, including neutral to alkaline pH and relatively high temperatures. Two representative anthraquinone and azo dyes, Reactive Blue 19 and Acid Orange 7, respectively, were rapidly decolorized (72% and 80%) by vlaccase treatment while natural laccase (nlaccase) achieved 40% and 32% decolorization. The toxicity of treated and untreated dyes was tested on model bacterial, algal, and insect cells. The inhibitory effects of dyes towards selected bacteria were reduced in vlaccase-treated samples. The chlorophyll synthesis in algae was less inhibited by dyes after vlaccase treatment. Furthermore, the toxicity of dye degradation products to insect cells was significantly mitigated in the vlaccase group. Collectively, these results indicate that vlaccase is a stable and strong enzymatic system for removing dyes from waters.

Keywords: Cytotoxicity; Decolorization; Immobilization; Ligninolytic; Protein nanocages.

MeSH terms

Azo Compounds / chemistry
Azo Compounds / toxicity
Biodegradation, Environmental
Coloring Agents / chemistry
Enzymes, Immobilized
Laccase* / metabolism
Nanoparticles*

Substances

Azo Compounds
Coloring Agents
Enzymes, Immobilized
Laccase