Microbial population changes during bioremediation of an experimental oil spill

Journal Article · Sun Aug 01 04:00:00 EDT 1999 · Applied and Environmental Microbiology

OSTI ID:678050

MacNaughton, S J; Stephen, J R; Chang, Y J ^[1]; Venosa, A D ^[2]; Davis, G A ^[3]; White, D C ^[1]

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1. Univ. of Tennessee, Knoxville, TN (United States). Center for Environmental Biotechnology
2. Environmental Protection Agency, Cincinnati, OH (United States)
3. Microbial Insights, Inc., Rockford, TN (United States)

Three crude oil bioremediation techniques were applied in a randomized block field experiment simulating a coastal oil spill. Four treatments (no oil control, oil alone, oil plus nutrients, and oil plus nutrients plus an indigenous inoculum) were applied. In situ microbial community structures were monitored by phospholipid fatty acid (PLFA) analysis and 16S rDNA PCR-denaturing gradient gel electrophoresis (DGGE) to (i) identify the bacterial community members responsible for the decontamination of the site and (ii) define an end point for the removal of the hydrocarbon substrate. The results of PLFA analysis demonstrated a community shift in all plots from primarily eukaryotic biomass to gram-negative bacterial biomass with time. PLFA profiles from the oiled plots suggested increased gram-negative biomass and adaptation to metabolic stress compared to unoiled controls. DGGE analysis of untreated control plots revealed a simple, dynamic dominant population structure throughout the experiment. This banding pattern disappeared in all oiled plots, indicating that the structure and diversity of the dominant bacterial community changed substantially. No consistent differences were detected between nutrient-amended and indigenous inoculum-treated plots, but both differed from the oil-only plots. Prominent bands were excised for sequence analysis and indicated that oil treatment encouraged the growth of gram-negative microorganisms within the {alpha}-proteobacteria and Flexibacter-Cytophaga-Bacteroides phylum. {alpha}-Proteobacteria were never detected in unoiled controls. PLFA analysis indicated that by week 14 the microbial community structures of the oiled plots were becoming similar to those of the unoiled controls from the same time point, but DGGE analysis suggested that major differences in the bacterial communities remained.

• Sponsoring Organization: National Science Foundation, Washington, DC (United States); USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-96OR22464
• OSTI ID: 678050
• Journal Information: Applied and Environmental Microbiology, Journal Name: Applied and Environmental Microbiology Journal Issue: 8 Vol. 65; ISSN AEMIDF; ISSN 0099-2240
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
BIODEGRADATION
BIOLOGICAL MARKERS
DNA
GENETIC VARIABILITY
HYDROCARBONS
OIL SPILLS
PETROLEUM
POLYMERASE CHAIN REACTION
REMEDIAL ACTION