title: Use of reporter-gene based bacteria to quantify phenanthrene biodegradation and toxicity in soil.
abstract: A phenanthrene-degrading bacterium, Sphingomonas paucimobilis EPA505 was used to construct two fluorescence-based reporter strains. Strain D harboring gfp gene was constructed to generate green fluorescence when the strain started to biodegrade phenanthrene. Strain S possessing gef gene was designed to die once phenanthrene biodegradation was initiated and thus to lose green fluorescence when visualized by a live/dead cell staining. Confocal laser scanning microscopic observation followed by image analysis demonstrates that the fluorescence intensity generated by strain D increased and the intensity by strain S decreased linearly at the phenanthrene concentration of up to 200 mg/L. Such quantitative increase and decrease of fluorescence intensity in strain D (i.e., from 1 to 11.90 ± 0.72) and strain S (from 1 to 0.40 ± 0.07) were also evident in the presence of Ottawa sand spiked with the phenanthrene up to 1000 mg/kg. The potential use of the reporter strains in quantitatively determining biodegradable or toxic phenanthrene was discussed.
authors.affiliation: Department of Civil and Environmental Engineering, Seoul National University, Gwanakno 599, Seoul 151-742, Republic of Korea.
authors.forename: Doyun
authors.initials: D
authors.lastname: Shin
authors.forename: Hee Sun
authors.initials: HS
authors.lastname: Moon
authors.forename: Chu-Ching
authors.initials: CC
authors.lastname: Lin
authors.forename: Tamar
authors.initials: T
authors.lastname: Barkay
authors.forename: Kyoungphile
authors.initials: K
authors.lastname: Nam
mesh_terms: D001673:Biodegradation, Environmental; D001681:Biological Assay / Q000379:methods; D052918:Environmental Restoration and Remediation / Q000379:methods*; D017930:Genes, Reporter; D050296:Microbial Viability / Q000187:drug effects; D010616:Phenanthrenes / Q000378:metabolism* / Q000633:toxicity*; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000378:metabolism* / Q000633:toxicity*; D020578:Sphingomonas / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity
chemical_list: D010616:Phenanthrenes; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; C031181:phenanthrene