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Conversion of crude oil to methane by a microbial consortium enriched from oil reservoir production waters.

Berdugo-Clavijo C, Gieg LM - Front Microbiol (2014)

Bottom Line: Here, Methanobacterium sp. were most abundant, as were bacterial members of the genus Pseudomonas and other known biofilm forming organisms.Our findings show that microorganisms enriched from petroleum reservoir waters can bioconvert crude oil components to methane both planktonically and in sandstone-packed columns as test systems.Further, the results suggest that different organisms may contribute to oil biodegradation within different phases (e.g., planktonic vs. sessile) within a subsurface crude oil reservoir.

View Article: PubMed Central - PubMed

Affiliation: Petroleum Microbiology Research Group, Department of Biological Sciences, University of Calgary Calgary, AB, Canada.

ABSTRACT
The methanogenic biodegradation of crude oil is an important process occurring in petroleum reservoirs and other oil-containing environments such as contaminated aquifers. In this process, syntrophic bacteria degrade hydrocarbon substrates to products such as acetate, and/or H2 and CO2 that are then used by methanogens to produce methane in a thermodynamically dependent manner. We enriched a methanogenic crude oil-degrading consortium from production waters sampled from a low temperature heavy oil reservoir. Alkylsuccinates indicative of fumarate addition to C5 and C6 n-alkanes were identified in the culture (above levels found in controls), corresponding to the detection of an alkyl succinate synthase encoding gene (assA/masA) in the culture. In addition, the enrichment culture was tested for its ability to produce methane from residual oil in a sandstone-packed column system simulating a mature field. Methane production rates of up to 5.8 μmol CH4/g of oil/day were measured in the column system. Amounts of produced methane were in relatively good agreement with hydrocarbon loss showing depletion of more than 50% of saturate and aromatic hydrocarbons. Microbial community analysis revealed that the enrichment culture was dominated by members of the genus Smithella, Methanosaeta, and Methanoculleus. However, a shift in microbial community occurred following incubation of the enrichment in the sandstone columns. Here, Methanobacterium sp. were most abundant, as were bacterial members of the genus Pseudomonas and other known biofilm forming organisms. Our findings show that microorganisms enriched from petroleum reservoir waters can bioconvert crude oil components to methane both planktonically and in sandstone-packed columns as test systems. Further, the results suggest that different organisms may contribute to oil biodegradation within different phases (e.g., planktonic vs. sessile) within a subsurface crude oil reservoir.

No MeSH data available.


Related in: MedlinePlus

Distribution of microbial sequence reads from pyrosequencing analysis identified at the phylum level of the 16S rRNA genes in the oil degrading methanogenic culture (A) and in the inoculated sand-packed column (B). Only abundances higher than 1% are shown.
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Figure 4: Distribution of microbial sequence reads from pyrosequencing analysis identified at the phylum level of the 16S rRNA genes in the oil degrading methanogenic culture (A) and in the inoculated sand-packed column (B). Only abundances higher than 1% are shown.

Mentions: The microbial community composition of the light-oil degrading enrichment before and after incubation in the sandstone-packed column experiment was assessed by pyrosequencing analysis of 16S rRNA genes. Overall, we observed a dramatic shift in the dominant microbial community members. First, the percentage of microbial reads from the Archaea, mainly methanogens, increased from 30% in the enrichment culture to 63% in the column system. At the phylum level, the community of the original enrichment culture was dominated by members of the phyla Euryarchaeota, Spirochaetes, Firmicutes, and Proteobacteria (Figure 4A). In contrast, the microbial community sampled from the residual oil column was dominated by members of Euryarchaeota, followed by members of Proteobacteria, and in less amount organisms from the phylum Actinobacteria, Firmicutes, and Spirochaetes (Figure 4B).


Conversion of crude oil to methane by a microbial consortium enriched from oil reservoir production waters.

Berdugo-Clavijo C, Gieg LM - Front Microbiol (2014)

Distribution of microbial sequence reads from pyrosequencing analysis identified at the phylum level of the 16S rRNA genes in the oil degrading methanogenic culture (A) and in the inoculated sand-packed column (B). Only abundances higher than 1% are shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4017130&req=5

Figure 4: Distribution of microbial sequence reads from pyrosequencing analysis identified at the phylum level of the 16S rRNA genes in the oil degrading methanogenic culture (A) and in the inoculated sand-packed column (B). Only abundances higher than 1% are shown.
Mentions: The microbial community composition of the light-oil degrading enrichment before and after incubation in the sandstone-packed column experiment was assessed by pyrosequencing analysis of 16S rRNA genes. Overall, we observed a dramatic shift in the dominant microbial community members. First, the percentage of microbial reads from the Archaea, mainly methanogens, increased from 30% in the enrichment culture to 63% in the column system. At the phylum level, the community of the original enrichment culture was dominated by members of the phyla Euryarchaeota, Spirochaetes, Firmicutes, and Proteobacteria (Figure 4A). In contrast, the microbial community sampled from the residual oil column was dominated by members of Euryarchaeota, followed by members of Proteobacteria, and in less amount organisms from the phylum Actinobacteria, Firmicutes, and Spirochaetes (Figure 4B).

Bottom Line: Here, Methanobacterium sp. were most abundant, as were bacterial members of the genus Pseudomonas and other known biofilm forming organisms.Our findings show that microorganisms enriched from petroleum reservoir waters can bioconvert crude oil components to methane both planktonically and in sandstone-packed columns as test systems.Further, the results suggest that different organisms may contribute to oil biodegradation within different phases (e.g., planktonic vs. sessile) within a subsurface crude oil reservoir.

View Article: PubMed Central - PubMed

Affiliation: Petroleum Microbiology Research Group, Department of Biological Sciences, University of Calgary Calgary, AB, Canada.

ABSTRACT
The methanogenic biodegradation of crude oil is an important process occurring in petroleum reservoirs and other oil-containing environments such as contaminated aquifers. In this process, syntrophic bacteria degrade hydrocarbon substrates to products such as acetate, and/or H2 and CO2 that are then used by methanogens to produce methane in a thermodynamically dependent manner. We enriched a methanogenic crude oil-degrading consortium from production waters sampled from a low temperature heavy oil reservoir. Alkylsuccinates indicative of fumarate addition to C5 and C6 n-alkanes were identified in the culture (above levels found in controls), corresponding to the detection of an alkyl succinate synthase encoding gene (assA/masA) in the culture. In addition, the enrichment culture was tested for its ability to produce methane from residual oil in a sandstone-packed column system simulating a mature field. Methane production rates of up to 5.8 μmol CH4/g of oil/day were measured in the column system. Amounts of produced methane were in relatively good agreement with hydrocarbon loss showing depletion of more than 50% of saturate and aromatic hydrocarbons. Microbial community analysis revealed that the enrichment culture was dominated by members of the genus Smithella, Methanosaeta, and Methanoculleus. However, a shift in microbial community occurred following incubation of the enrichment in the sandstone columns. Here, Methanobacterium sp. were most abundant, as were bacterial members of the genus Pseudomonas and other known biofilm forming organisms. Our findings show that microorganisms enriched from petroleum reservoir waters can bioconvert crude oil components to methane both planktonically and in sandstone-packed columns as test systems. Further, the results suggest that different organisms may contribute to oil biodegradation within different phases (e.g., planktonic vs. sessile) within a subsurface crude oil reservoir.

No MeSH data available.


Related in: MedlinePlus