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

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