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Effect of high pressure on hydrocarbon-degrading bacteria.

Schedler M, Hiessl R, Valladares Juárez AG, Gust G, Müller R - AMB Express (2014)

Bottom Line: However, above this pressure growth decreased and at 12 MPa or more no more growth was observed.Nevertheless, S. yanoikuyae continued to convert naphthalene at pressure >12 MPa, although at a lower rate than at 0.1 MPa.These results show that high pressure has a strong influence on the biodegradation of crude oil components and that, contrary to previous assumptions, the role of pressure cannot be discounted when estimating the biodegradation and ultimate fate of deep-sea oil releases such as the Deepwater Horizon event.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Technical Biocatalysis, Hamburg University of Technology, Hamburg 21073, Germany.

ABSTRACT
The blowout of the Deepwater Horizon in the Gulf of Mexico in 2010 occurred at a depth of 1500 m, corresponding to a hydrostatic pressure of 15 MPa. Up to now, knowledge about the impact of high pressure on oil-degrading bacteria has been scarce. To investigate how the biodegradation of crude oil and its components is influenced by high pressures, like those in deep-sea environments, hydrocarbon degradation and growth of two model strains were studied in high-pressure reactors. The alkane-degrading strain Rhodococcus qingshengii TUHH-12 grew well on n-hexadecane at 15 MPa at a rate of 0.16 h(-1), although slightly slower than at ambient pressure (0.36 h(-1)). In contrast, the growth of the aromatic hydrocarbon degrading strain Sphingobium yanoikuyae B1 was highly affected by elevated pressures. Pressures of up to 8.8 MPa had little effect on growth of this strain. However, above this pressure growth decreased and at 12 MPa or more no more growth was observed. Nevertheless, S. yanoikuyae continued to convert naphthalene at pressure >12 MPa, although at a lower rate than at 0.1 MPa. This suggests that certain metabolic functions of this bacterium were inhibited by pressure to a greater extent than the enzymes responsible for naphthalene degradation. These results show that high pressure has a strong influence on the biodegradation of crude oil components and that, contrary to previous assumptions, the role of pressure cannot be discounted when estimating the biodegradation and ultimate fate of deep-sea oil releases such as the Deepwater Horizon event.

No MeSH data available.


Related in: MedlinePlus

CFU counts (▲) ofS. yanoikuyaeB1 growing on naphthalene (■) at different pressures.S. yanoikuyae B1 was cultivated at room temperature. The CFUs were counted after an incubation time of 70 h and determined in triplicate. Standard deviations are shown. The dashed line indicates the starting naphthalene concentration (▬ ▬ ▬), the stippled line is the starting cell number (● ● ●) at 0 h.
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Figure 4: CFU counts (▲) ofS. yanoikuyaeB1 growing on naphthalene (■) at different pressures.S. yanoikuyae B1 was cultivated at room temperature. The CFUs were counted after an incubation time of 70 h and determined in triplicate. Standard deviations are shown. The dashed line indicates the starting naphthalene concentration (▬ ▬ ▬), the stippled line is the starting cell number (● ● ●) at 0 h.

Mentions: Since S. yanoikuyae B1 did not grow at 13.9 MPa, we conducted additional experiments to determine the maximum pressure at which growth was possible. S. yanoikuyae B1 was incubated for 70 h on naphthalene at different pressures in the range between 0.1 MPa and 13 MPa (Figure 4). In the range of 0.1 to 8.8 MPa, the CFU counts remained relatively constant, but decreased when 8.8 MPa was exceeded. In incubations at and above 12 MPa no growth occurred after 70 h cultivation time and viable cell counts were lower than at the start of the incubation.


Effect of high pressure on hydrocarbon-degrading bacteria.

Schedler M, Hiessl R, Valladares Juárez AG, Gust G, Müller R - AMB Express (2014)

CFU counts (▲) ofS. yanoikuyaeB1 growing on naphthalene (■) at different pressures.S. yanoikuyae B1 was cultivated at room temperature. The CFUs were counted after an incubation time of 70 h and determined in triplicate. Standard deviations are shown. The dashed line indicates the starting naphthalene concentration (▬ ▬ ▬), the stippled line is the starting cell number (● ● ●) at 0 h.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4230898&req=5

Figure 4: CFU counts (▲) ofS. yanoikuyaeB1 growing on naphthalene (■) at different pressures.S. yanoikuyae B1 was cultivated at room temperature. The CFUs were counted after an incubation time of 70 h and determined in triplicate. Standard deviations are shown. The dashed line indicates the starting naphthalene concentration (▬ ▬ ▬), the stippled line is the starting cell number (● ● ●) at 0 h.
Mentions: Since S. yanoikuyae B1 did not grow at 13.9 MPa, we conducted additional experiments to determine the maximum pressure at which growth was possible. S. yanoikuyae B1 was incubated for 70 h on naphthalene at different pressures in the range between 0.1 MPa and 13 MPa (Figure 4). In the range of 0.1 to 8.8 MPa, the CFU counts remained relatively constant, but decreased when 8.8 MPa was exceeded. In incubations at and above 12 MPa no growth occurred after 70 h cultivation time and viable cell counts were lower than at the start of the incubation.

Bottom Line: However, above this pressure growth decreased and at 12 MPa or more no more growth was observed.Nevertheless, S. yanoikuyae continued to convert naphthalene at pressure >12 MPa, although at a lower rate than at 0.1 MPa.These results show that high pressure has a strong influence on the biodegradation of crude oil components and that, contrary to previous assumptions, the role of pressure cannot be discounted when estimating the biodegradation and ultimate fate of deep-sea oil releases such as the Deepwater Horizon event.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Technical Biocatalysis, Hamburg University of Technology, Hamburg 21073, Germany.

ABSTRACT
The blowout of the Deepwater Horizon in the Gulf of Mexico in 2010 occurred at a depth of 1500 m, corresponding to a hydrostatic pressure of 15 MPa. Up to now, knowledge about the impact of high pressure on oil-degrading bacteria has been scarce. To investigate how the biodegradation of crude oil and its components is influenced by high pressures, like those in deep-sea environments, hydrocarbon degradation and growth of two model strains were studied in high-pressure reactors. The alkane-degrading strain Rhodococcus qingshengii TUHH-12 grew well on n-hexadecane at 15 MPa at a rate of 0.16 h(-1), although slightly slower than at ambient pressure (0.36 h(-1)). In contrast, the growth of the aromatic hydrocarbon degrading strain Sphingobium yanoikuyae B1 was highly affected by elevated pressures. Pressures of up to 8.8 MPa had little effect on growth of this strain. However, above this pressure growth decreased and at 12 MPa or more no more growth was observed. Nevertheless, S. yanoikuyae continued to convert naphthalene at pressure >12 MPa, although at a lower rate than at 0.1 MPa. This suggests that certain metabolic functions of this bacterium were inhibited by pressure to a greater extent than the enzymes responsible for naphthalene degradation. These results show that high pressure has a strong influence on the biodegradation of crude oil components and that, contrary to previous assumptions, the role of pressure cannot be discounted when estimating the biodegradation and ultimate fate of deep-sea oil releases such as the Deepwater Horizon event.

No MeSH data available.


Related in: MedlinePlus