High-Yield Laccase-Producing Strains Constructed by Protoplast Fusion Between Bacterium and Fungus

Abstract

This study is based on the construction of high-yield laccase-producing fusant achieved by inter-kingdom protoplast fusion between Pleurotus ostreatus and Escherichia coli. The optimized protoplasts formation and regeneration conditions were demonstrated with the presence of 1.5% cellulase +1.0% snailase and 0.6M mannitol at 30°C for 3h. The fusants were screened for different characteristics between two parental strains and further identified by laccase activity, offering one of the genetically stable fusants, Strain F. The fusant F produced the highest yield of laccase, being about 22% higher than that of the parental strain. The results suggest that the protoplast fusion technique can be considered as a promising technique for the control of environmental pollution.