![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
Previous Article | Next Article 
Applied and Environmental Microbiology, June 2001, p. 2683-2691, Vol. 67, No. 6
Biotechnology Center for Agriculture and the
Environment1 and Department of
Biochemistry and Microbiology,2 Cook
College, Rutgers University, New Brunswick, New Jersey 08901
Received 25 September 2000/Accepted 12 March 2001
Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria were
isolated from contaminated estuarine sediment and salt marsh rhizosphere by enrichment using either naphthalene, phenanthrene, or
biphenyl as the sole source of carbon and energy. Pasteurization of
samples prior to enrichment resulted in isolation of gram-positive, spore-forming bacteria. The isolates were characterized using a variety
of phenotypic, morphologic, and molecular properties. Identification of
the isolates based on their fatty acid profiles and partial 16S rRNA
gene sequences assigned them to three main bacterial groups:
gram-negative pseudomonads; gram-positive, non-spore-forming nocardioforms; and the gram-positive, spore-forming group,
Paenibacillus. Genomic digest patterns of all isolates were
used to determine unique isolates, and representatives from each
bacterial group were chosen for further investigation. Southern
hybridization was performed using genes for PAH degradation from
Pseudomonas putida NCIB 9816-4, Comamonas
testosteroni GZ42, Sphingomonas yanoikuyae B1, and
Mycobacterium sp. strain PY01. None of the isolates from
the three groups showed homology to the B1 genes, only two nocardioform
isolates showed homology to the PY01 genes, and only members of the
pseudomonad group showed homology to the NCIB 9816-4 or GZ42 probes.
The Paenibacillus isolates showed no homology to any of the
tested gene probes, indicating the possibility of novel genes for PAH
degradation. Pure culture substrate utilization experiments using
several selected isolates from each of the three groups showed that the
phenanthrene-enriched isolates are able to utilize a greater number of
PAHs than are the naphthalene-enriched isolates. Inoculating two of the
gram-positive isolates to a marine sediment slurry spiked with a
mixture of PAHs (naphthalene, fluorene, phenanthrene, and pyrene) and
biphenyl resulted in rapid transformation of pyrene, in addition to the
two- and three-ringed PAHs and biphenyl. This study indicates that the
rhizosphere of salt marsh plants contains a diverse population of
PAH-degrading bacteria, and the use of plant-associated microorganisms
has the potential for bioremediation of contaminated sediments.
0099-2240/01/$04.00+0 DOI: 10.1128/AEM.67.6.2683-2691.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Isolation and Characterization of Polycyclic
Aromatic Hydrocarbon-Degrading Bacteria Associated with the
Rhizosphere of Salt Marsh Plants
*
Corresponding author. Mailing address: Department of
Biochemistry and Microbiology, Cook College, Rutgers University, 76 Lipman Dr., New Brunswick, NJ 08901-8525. Phone: (732) 932-9763, ext. 326. Fax: (732) 932-8965. E-mail:
haggblom{at}aesop.rutgers.edu.
Present address: Avon Products, Inc., Suffern, NY 10901-5605.
This article has been cited by other articles:
| J. Bacteriol. | Microbiol. Mol. Biol. Rev. | Eukaryot. Cell | All ASM Journals |
|---|
