Microbial degradation of aromatics and saturates in Prudhoe Bay crude oil as determined by glass capillary gas chromatography

Water samples obtained from three different marine environments (including a commercial harbor, a pristine area, and an oil tanker dock area) from the coast of Washington State were challenged with Prudhoe Bay crude oil under shake-flask conditions at 8 °C. Replicate cultures were grown with and wit...

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Bibliographic Details
Published in:Canadian Journal of Microbiology
Main Authors: Fedorak, P. M., Westlake, D. W. S.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1981
Subjects:
Online Access:http://dx.doi.org/10.1139/m81-066
http://www.nrcresearchpress.com/doi/pdf/10.1139/m81-066
Description
Summary:Water samples obtained from three different marine environments (including a commercial harbor, a pristine area, and an oil tanker dock area) from the coast of Washington State were challenged with Prudhoe Bay crude oil under shake-flask conditions at 8 °C. Replicate cultures were grown with and without nitrogen (NO 3 − , NH 4 + ) and phosphate supplementation. After varying incubation periods, the residual oil was extracted and separated on silica gel columns into saturate and aromatic fractions and these were analyzed by glass capillary gas chromatography to detect the degradation of various compounds. After 27 days of incubation, both the aromatic and saturate fractions were extensively degraded by the microorganisms from these environments when supplemented with nitrogen and phosphorus. Without nutrient supplementation, the aromatics were more readily attacked than the saturates by the populations from the pristine environment and from the commercial harbor area. Under these limited nutrient conditions, samples from near oil tanker docks showed moderate degradation of both the saturate and aromatic fractions. Time course studies, using nutrient-supplemented marine samples, showed that the simple aromatics (e.g., naphthalene and 2-methylnaphthalene) were more readily degraded than the n-alkanes. However, once the breakdown of these saturates commenced, these were quickly removed from the oil. The aromatic degradation continued to progress from lower molecular weight, less complex molecules to larger, more complex molecules in the approximate series C 2 naphthalenes; phenanthrene and dibenzothiophene; C 3 naphthalenes and methylphenathrenes; C 2 phenanthrenes.