title: Application of a floc-forming genetically engineered microorganism to a sequencing batch reactor for phenolic wastewater treatment.
abstract: For enhancing the survival of genetically engineered microorganisms (GEMs) in activated sludge processes, the use of a floc-forming bacterium as the host for a recombinant plasmid was proposed. The floc-forming and phenol-degrading GEM Sphingomonas paucimobilis 551 (pS10-45) was cultured to demonstrate this proposal. Although the maximum growth rate of the host strain S. paucimobilis 551 was low and the recombinant plasmid pS10-45 was unstable in the host, the resultant GEM S. paucimobilis 551 (pS10-45) was difficult to wash out together with the effluent, and it maintained population 3-4 times higher than the non-floc-forming GEM Escherichia coli HB101 (pS10-45) in a model activated sludge process operated in a sequencing batch mode. In the long run, the GEM-inoculated activated sludge process showed better phenol removal ability by the recombinant plasmid and better sludge settlement by the host strain.
authors.affiliation: Department of Environmental Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 Japan.
authors.forename: S
authors.initials: S
authors.lastname: Soda
authors.forename: K
authors.initials: K
authors.lastname: Uesugi
authors.forename: M
authors.initials: M
authors.lastname: Ike
authors.forename: M
authors.initials: M
authors.lastname: Fujita