Effects of potential inducers to enhance laccase production and evaluating concomitant enzyme immobilisation

ABSTRACT

This work investigated non-polar solvent hexane and polar solvents methanol and ethanol as inducers besides a well-known inducer, copper, for laccase production with and without mesoporous silica-covered plastic packing under sterilised and unsterilised conditions. The potential of waste-hexane water, which is generated during the mesoporous silica production process, was also investigated as a laccase inducer. During the study, the free and immobilised laccase activity on the packing was measured. The results showed that the highest total laccase activity, approximately 10,000 Units, was obtained under sterilised conditions with 0.5 mM copper concentration. However, no immobilised laccase activity was detected except in the copper and ethanol sets under unsterilised conditions. The maximum immobilised laccase activity of the sets that used waste hexane as an inducer was 1.25 U/mg packing. According to its significant performance, waste hexane can be an alternative inducer under sterilised conditions. Concomitant immobilised packing showed satisfactory laccase activities and could be a promising method to reduce operation costs and improve the cost-efficiency of enzymatic processes in wastewater treatment plants.

GRAPHICAL ABSTRACT

KEYWORDS:

• Laccase inducers
• fungal laccase
• Pleurotus dryinus
• enzyme immobilisation
• silica-covered packing

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data supporting this study’s findings are available from the corresponding author, [YG], upon reasonable request.

Additional information

Funding

The authors would like to express their special thanks and gratitude to TUBITAK (2214-A International Research Fellowship Program) – Natural Sciences and Engineering Research Council of Canada (NSERC), and Mitacs for their financial support. The authors are also grateful to Olivier Savary, Environmental Engineering Laboratory, Université de Sherbrooke, for their help and support.