title: Determination of phenanthrene bioavailability by using a self-dying reporter bacterium: test with model solids and soil.
abstract: The present study was conducted to investigate the performance and feasibility of a self-dying reporter bacterium to visualize and quantify phenanthrene bioavailability in soil. The self-dying reporter bacterium was designed to die on the initiation of phenanthrene biodegradation. The viability of the reporter bacterium was determined by a fluorescence live/dead cell staining method and visualized by confocal laser scanning microscopic observation. Phenanthrene was spiked into four types of model solids and a sandy loam. The bioavailability of phenanthrene to the reporter bacterium was remarkably declined with the hydrophobicity of the model solids: essentially no phenanthrene was biodegraded in the presence of 9-nm pores and about 35.8% of initial phenanthrene was biodegraded without pores. Decrease in bioavailability was not evident in the nonporous hydrophilic bead, but a small decrease was observed in the porous hydrophilic bead at 1000 mg/kg of phenanthrene. The fluorescence intensity was commensurate with the extent of phenanthrene biodegradation by the reporter bacterium at the concentration range from 50 to 500 mg/kg. Such a quantitative relationship was also confirmed with a sandy loam spiked up to 1000 mg/kg of phenanthrene. This reporter bacterium may be a useful means to determine phenanthrene bioavailability in soil.
authors.affiliation: Mineral Resources Research Division, Metal Recovery Department, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon 305-350, Republic of Korea.
authors.forename: Doyun
authors.initials: D
authors.lastname: Shin
authors.forename: Kyoungphile
authors.initials: K
authors.lastname: Nam
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D001682:Biological Availability; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005453:Fluorescence; D058608:Nanopores; D010616:Phenanthrenes / Q000378:metabolism*; D016062:Porosity; D012987:Soil; D012988:Soil Microbiology
chemical_list: D010616:Phenanthrenes; D012987:Soil; C031181:phenanthrene