Biodegradation of single pyrene and mixtures of pyrene by a fusant bacterial strain F14

• Biodegradation of high-molecular weight PAH pyrene using fusant strain.
• F14 has higher degradation ability on pyrene than its parental strain.
• The substrate interactions in binary and ternary mixtures of pyrene were studied.
• Investigating the kinetics of pyrene degradation in binary and ternary mixtures.
• The metabolite of 4, 5-dihydropyrene was detected during pyrene degradation.

The aim of the present study was to investigate pyrene degradation by a functional strain F14, which was constructed through protoplast fusion between Sphingomonas sp. GY2B and Pseudomonas sp. GP3A. The ability of F14 to degrade pyrene increased from 18% to 46% with the decrease of pyrene concentration from 100 mg L−1 to 15 mg L−1 within 10 days. When pyrene was in binary mixture with phenanthrene or naphthalene, about 42% and 78% of pyrene were biodegraded by F14, respectively, indicating the presence of naphthalene or phenanthrene enhanced pyrene degradation, and the enhanced effect of 2-ring naphthalene was more obvious than that of 3-ring phenanthrene. Detection of metabolites 4, 5-dihydropyrene during pyrene degradation further confirmed the degradation capability of fusion strain F14. The present study showed that fusion strain F14 have a promising application in bioremediation of PAHs contaminated environment.