A high throughput screening and characterization of laccase-producing bacterium Serratia quinivorans AORB19 that exhibits lignin degradation traits, dye decolorization efficiency, and enhanced laccase production in biomass

Abstract

Laccase (EC 1.10.3.2) assumes a vital role in the degradation of lignin by utilizing oxygen as an oxidant and catalyzing bond cleavage in both phenolic and nonphenolic lignin model compounds. However, their industrial application is limited due to reduced enzymatic activity and lower tolerance to extreme conditions in most laccases isolated from microorganisms. To address these challenges, bioprospecting for strains harboring novel laccases with enhanced activity and versatile properties is paramount. Natural biodegradation processes offer promises for lignin degradation, and rapid screening methods aid in isolating microorganisms secreting extracellular lignin-degrading enzymes, including laccases. In our study, we developed a novel high-throughput screening process to isolate a promising lignin-degrading bacterium from decomposed wood samples. Whole-genome analysis and LC-UV (Liquid Chromatography-Ultraviolet Detection) analysis was employed to identify the species and assess its lignin-degrading traits. This bacterium exhibited significant extracellular laccase production and was biochemically characterized. Moreover, the potential of this bacterium in bioremediation, specifically in the decolorization of two major dyes, was probed. Additionally, the laccase secretion capabilities of the bacterial strain were assessed by utilizing low-cost industrial wastes from the Canadian agro-industries. [...]