title: Application of the knowledge-based approach to strain selection for a bioaugmentation process of phenanthrene- and Cr(VI)-contaminated soil.
abstract: OBJECTIVE
  The objective of this study was to apply the knowledge-based approach to the selection of an inoculum to be used in bioaugmentation processes to facilitate phenanthrene degradation in phenanthrene- and Cr(VI)-co-contaminated soils.
  
  
  RESULTS
  The bacterial community composition of phenanthrene and phenanthrene- and Cr(VI)-co-contaminated microcosms, determined by denaturing gradient gel electrophoresis analysis, showed that members of the Sphingomonadaceae family were the predominant micro-organisms. However, the Cr(VI) contamination produced a selective change of predominant Sphingomonas species, and in co-contaminated soil microcosms, a population closely related to Sphingomonas paucimobilis was naturally selected. The bioaugmentation process was carried out using the phenanthrene-degrading strain S. paucimobilis 20006FA, isolated and characterized in our laboratory. Although the strain showed a low Cr(VI) resistance (0·250 mmol l⁻¹); in liquid culture, it was capable of reducing chromate and degrading phenanthrene simultaneously.
  
  
  CONCLUSIONS
  The inoculation of this strain managed to moderate the effect of the presence of Cr(VI), increasing the biological activity and phenanthrene degradation rate in co-contaminated microcosm.
  
  
  CONCLUSIONS
  In this study, we have applied a novel approach to the selection of the adequate inoculum to enhance the phenanthrene degradation in phenanthrene- and Cr(VI)-co-contaminated soils.
authors.affiliation: Centro de Investigación y Desarrollo en Fermentaciones Industriales, CINDEFI (UNLP; CCT-La Plata, CONICET), La Plata, Argentina. guri@biol.unlp.edu.ar
authors.forename: A
authors.initials: A
authors.lastname: Ibarrolaza
authors.forename: B M
authors.initials: BM
authors.lastname: Coppotelli
authors.forename: M T
authors.initials: MT
authors.lastname: Del Panno
authors.forename: E R
authors.initials: ER
authors.lastname: Donati
authors.forename: I S
authors.initials: IS
authors.lastname: Morelli
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001673:Biodegradation, Environmental; D002857:Chromium / Q000378:metabolism*; D010616:Phenanthrenes / Q000378:metabolism*; D010802:Phylogeny; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D020578:Sphingomonas / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D010616:Phenanthrenes; D012989:Soil Pollutants; D002857:Chromium; C031181:phenanthrene