Improved laccase production in Pleurotus djamor RP by atmospheric and room temperature plasma (ARTP) mutagenesis

Abstract

Background: Pleurotus djamor is an edible mushroom with medicinal properties, and degrades lignocellulose by producing enzymes that have a variety of industrial applications. The aim of this study was to improve laccase producing potential of P. djamor that may easily convert lignocellulose waste into high-value products.

Results: In the present study, protoplast of the newly isolated fungus P. djamor RP was mutated by atmospheric pressure and room temperature plasma (ARTP) method. Guaiacol was used as an indicator for the rapid visual appearance of laccase positives in the screening process. From the results of preliminary screening, 10 promising positive mutants with a maximum laccase production were selected for further experimentation. Lac activity by the ABTS method showed that the mutant P. djamor strain 51-4 exhibited the maximum laccase production of 494.44 U/L in shake flask cultivation, which was 86.36% higher than wild strain. Notably, the other mutant P. djamor strain 62-27 exhibits a higher laccase production of 26.06 U/g which was 30.28% higher than wild strain when grown on solid-state fermentation. In addition to a higher yield of laccase, all mutants showed better growth and genetic stability than the wild strain.

Conclusions: P. djamor RP mutants with high laccase-producing potential were developed by ARTP Mutagenesis technique, and these isolates could be used as a possible candidate for lignocellulose conversion into high-value products.