Isolation and characterization of a novel sphingomonad capable of growth with chrysene as sole carbon and energy source

FEMS Microbiol Lett. 2004 Dec 15;241(2):143-50. doi: 10.1016/j.femsle.2004.10.012.


A bacterial strain able to grow in pure culture with chrysene as sole added carbon and energy source was isolated from PAH-contaminated soil after successive enrichment cultures in a biphasic growth medium. Initially, growth occurred in the form of a biofilm at the interface between the aqueous and non-aqueous liquid phases. However, after a certain time, a transition occurred in the enrichment cultures, with growth occurring in suspension and a concomitant increase in the rate of chrysene degradation. The strain responsible for chrysene degradation in these cultures, named Sphingomonas sp. CHY-1, was identified by 16S rDNA sequencing as a novel sphingomonad, the closest relative in the databases being Sphingomonas xenophaga BN6T (96% sequence identity). Both these strains clustered with members of the genera Sphingobium and Rhizomonas, but could not be categorically assigned to either genus. Sphingomonas sp. CHY-1 was characterized in terms of its growth on chrysene and other PAH, and the kinetics of chrysene degradation and 14C-chrysene mineralization were measured. At an initial chrysene concentration of 0.5 g l(-1) silicone oil, and an organic/aqueous phase ratio of 1:4, chrysene was 50% degraded after 5 days incubation and 97.5% degraded after 35 days. The protein content of cultures reached a maximum value of 11.5 microg ml(-1) aqueous phase, corresponding to 92 mg g(-1) chrysene. 14C-labelled chrysene was 50% mineralized after 6-8 weeks incubation, 10.7% of the radioactivity was incorporated into cell biomass and 8.4% was found in the aqueous culture supernatant. Sphingomonas sp. CHY-1 also grew on naphthalene, phenanthrene and anthracene, and naphthalene was the preferred substrate, with a doubling time of 6.9 h.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biodegradation, Environmental
  • Biofilms / growth & development
  • Chrysenes / metabolism*
  • Culture Media
  • DNA, Ribosomal / analysis
  • Molecular Sequence Data
  • Polycyclic Aromatic Hydrocarbons / metabolism
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA
  • Soil Microbiology*
  • Soil Pollutants / metabolism*
  • Sphingomonas / classification*
  • Sphingomonas / growth & development
  • Sphingomonas / isolation & purification*
  • Sphingomonas / metabolism


  • Chrysenes
  • Culture Media
  • DNA, Ribosomal
  • Polycyclic Aromatic Hydrocarbons
  • RNA, Ribosomal, 16S
  • Soil Pollutants
  • chrysene

Associated data

  • GENBANK/AJ715526