GERBAM — Deuxième Colloque International de Bactériologie marine — CNRS, Brest, 1-5 octobre 1984
IFREMER, Actes de Colloques, 3, 1986, pp. 601-610
72
PLASMID-ASSOCIATED PHENANTHRENE DEGRADATION BY CHESAPEAKE BAY SEDIMENT BACTERIA
G.C. OKPOKWASILI, C.C. SOMERVILLE, D.J. GRIMES, and R.R. COLWELL
Department of Microbiology, University of Maryland, COLLEGE PARK., Maryland,
20742 (USA)
ABSTRACT - A differential, phenanthrene-enrichment agar plating technique was used to isolate phenanthrenedegrading bacteria from phenanthrene-enriched Chesapeake Bay sediment. One of the isolates, a yellow
pigmented, slime-producing, Gram- negative rod identified as Flavobacterium sp. has been studied in detail. It
has been found to carry a single plasmid with a mass of about 34 megadaltons. Results of hydrocarbon
adherence tests showed that the organism adhered only minimally to n-octane and n-hexadecane, but emulsified
cyclohexylbenzene and 1, 2, 3, 4, -tetrahydronaphthalene (tetralin). Curing of the plasmid with 3 µg/ml
novobiocin resulted in loss of phenanthrene clearing ability. Ability to degrade phenanthrene was confirmed
using
14 C-labeled phenanthrene.
Key words : phenanthrene, plasmid, degradation, differential, enrichment, adherence, emulsification.
RÉSUMÉ - Une technique distinctive sur boîtes d’agar enrichies en phénanthrène a été utilisée pour isoler des
bactéries dégradant le phénanthrène à partir du sédiment enrichi en phénanthrène de la baie de Chesapeake. Un
des isolats, un bâtonnet pigmenté en jaune, produisant du mucus, Gram négatif et identifié comme étant un
Flavobacterium sp a fait l’objet d’une étude détaillée. Il est porteur d’un seul plasmide, d’une masse de 34
mégadaltons. Les résultats des tests d’adhésion aux hydrocarbures montrent qu’il se fixe faiblement seulement
au n- octane et au n-hexadécane, mais émulsionne le cyclobenzène et le 1, 2, 3, 4, -tétrahydronaphtalène
(tetralin). Un traitement du plasmide par 3 µg/ ml de novobiocine aboutit à la perte de sa capacité à dégrader le
phénanthrène. La capacité à dégrader le phénanthrène est confirmée par utilisation de phénanthrène
marqué au
14 C.
Mots clés : phénanthrène, plasmide, dégradation, distinctif, enrichissement, adhésion, émulsification.
INTRODUCTION
For the past several decades, chronic oil pollution in the marine environment with its
attendant tainting of seafood, and entry of potentially carcinogenic components of the
aromatic fraction of crude oil into the food chain, was a problem that has directed the
attention of researchers towards hydrocarbon biodegradation. Also, the proposed commercial production of synthetic fuels from coal as a means of alleviating shortages of
liquid hydrocarbon fuels, strengthens fears about environmental hydrocarbon pollution
and concomitant dangers posed to human health. Polycyclic aromatic hydrocarbons
(PAHs) are widely distributed in the environment and they are formed partly as a result of
high temperature pyrolytic processes (Blumer, 1976). They are important contaminants
because they persist in natural ecosystems (Platt and Mackie, 1980). These compounds
find their way into the estuarine and marine ecosystems through natural submarine
seepage of petroleum and accidental spillage which occur in the production, transport,
and utilization of petroleum. Additionally, low amounts of PAHs are released into the
environment by a wide variety of natural and man-made sources, such as forest fires,
601
IFREMER, Actes de Colloques, 3, 1986, pp. 601-610
72
PLASMID-ASSOCIATED PHENANTHRENE DEGRADATION BY CHESAPEAKE BAY SEDIMENT BACTERIA
G.C. OKPOKWASILI, C.C. SOMERVILLE, D.J. GRIMES, and R.R. COLWELL
Department of Microbiology, University of Maryland, COLLEGE PARK., Maryland,
20742 (USA)
ABSTRACT - A differential, phenanthrene-enrichment agar plating technique was used to isolate phenanthrenedegrading bacteria from phenanthrene-enriched Chesapeake Bay sediment. One of the isolates, a yellow
pigmented, slime-producing, Gram- negative rod identified as Flavobacterium sp. has been studied in detail. It
has been found to carry a single plasmid with a mass of about 34 megadaltons. Results of hydrocarbon
adherence tests showed that the organism adhered only minimally to n-octane and n-hexadecane, but emulsified
cyclohexylbenzene and 1, 2, 3, 4, -tetrahydronaphthalene (tetralin). Curing of the plasmid with 3 µg/ml
novobiocin resulted in loss of phenanthrene clearing ability. Ability to degrade phenanthrene was confirmed
using
14 C-labeled phenanthrene.
Key words : phenanthrene, plasmid, degradation, differential, enrichment, adherence, emulsification.
RÉSUMÉ - Une technique distinctive sur boîtes d’agar enrichies en phénanthrène a été utilisée pour isoler des
bactéries dégradant le phénanthrène à partir du sédiment enrichi en phénanthrène de la baie de Chesapeake. Un
des isolats, un bâtonnet pigmenté en jaune, produisant du mucus, Gram négatif et identifié comme étant un
Flavobacterium sp a fait l’objet d’une étude détaillée. Il est porteur d’un seul plasmide, d’une masse de 34
mégadaltons. Les résultats des tests d’adhésion aux hydrocarbures montrent qu’il se fixe faiblement seulement
au n- octane et au n-hexadécane, mais émulsionne le cyclobenzène et le 1, 2, 3, 4, -tétrahydronaphtalène
(tetralin). Un traitement du plasmide par 3 µg/ ml de novobiocine aboutit à la perte de sa capacité à dégrader le
phénanthrène. La capacité à dégrader le phénanthrène est confirmée par utilisation de phénanthrène
marqué au
14 C.
Mots clés : phénanthrène, plasmide, dégradation, distinctif, enrichissement, adhésion, émulsification.
INTRODUCTION
For the past several decades, chronic oil pollution in the marine environment with its
attendant tainting of seafood, and entry of potentially carcinogenic components of the
aromatic fraction of crude oil into the food chain, was a problem that has directed the
attention of researchers towards hydrocarbon biodegradation. Also, the proposed commercial production of synthetic fuels from coal as a means of alleviating shortages of
liquid hydrocarbon fuels, strengthens fears about environmental hydrocarbon pollution
and concomitant dangers posed to human health. Polycyclic aromatic hydrocarbons
(PAHs) are widely distributed in the environment and they are formed partly as a result of
high temperature pyrolytic processes (Blumer, 1976). They are important contaminants
because they persist in natural ecosystems (Platt and Mackie, 1980). These compounds
find their way into the estuarine and marine ecosystems through natural submarine
seepage of petroleum and accidental spillage which occur in the production, transport,
and utilization of petroleum. Additionally, low amounts of PAHs are released into the
environment by a wide variety of natural and man-made sources, such as forest fires,
601