Selective curing of the endogenous plasmid pSF3 encoding organophosphorus hydrolase in Sphingobium fuliginis ATCC 27551

Sphingobium fuliginis ATCC 27551 degrades organophosphorus pollutants by organophosphorus hydrolase (OPH) encoded on a plasmid pSF3. The replacement plasmid with the same replication-associated genes was used to cure pSF3. By the selection of antibiotic resistance, pSF3 was eliminated without changing other plasmids. The cured strain would be useful to construct a strain capable of large-scale production of OPH.