Bacterial Laccase: Recent Advances in Production, Engineering Strategies, and Diagnostic Applications

Bacterial laccases are multicopper oxidase enzymes that are able to catalyze the oxidation reaction of phenolic and non-phenolic substrates followed by the reduction reaction of molecular oxygen to water as the only byproduct. It exhibits high stability under harsh conditions and can be produced recombinantly in various microbial hosts. Herein, we review recent advances in bacterial laccase research over the past decade, which focus on production technologies, protein engineering strategies, and diagnostic applications. We also discuss how synthetic biology has overcome historical limitations in heterologous expression and enabled industrial-scale production in hosts such as Escherichia coli and Bacillus subtilis. In addition, we analyzed how directed evolution, rational design, post-translational modifications, and computational modeling have enhanced the catalytic properties of laccases. In the final chapter, we evaluate the use of bacterial laccases as peroxidase alternatives for detecting clinical analytes like dopamine, uric acid, and glucose biosensing and point-of-care diagnostics. This review integrated more than 120 peer-reviewed papers and provides a comprehensive assessment of how bacterial laccases are transitioning from laboratory curiosities to practical biocatalysts in environmental monitoring, industrial processing, and medical diagnostics. We conclude the review by identifying remaining challenges and future research directions for realizing the full potential of these versatile enzymes.