Chapter 24, Problem 1CF

Summary Introduction

To describe:

The place from where the methane-consuming bacteria came into the Gulf of Mexico.

Concept introduction:

The largest oil spill that ever occurred, took place in the Gulf of Mexico in 2010. 4.9 million barrels containing 205.8 million gallons of British Petroleum oil were estimated to have been released across 665 miles of coastline, causing severe damage to the environment. The most abundant substance released in the spill was methane, which formed a 110-220 yards thick layer in the ocean. This concentration of methane was 10,000-100,000 times more than the normal concentrations. However, the methane concentration reduced to negligible amounts within a few months due to its consumption by bacteria.

Explanation of Solution

The bacteria that consume methane are known as methanogens or methanotrophs. These organisms are found naturally in the environment, especially in the ocean floor, near the methane-seeping vents present there. Methanogens utilize oxygen to metabolize methane. The rate at which methanogens that were present in the ocean consumed methane released during the oil spill was enhanced by the addition of dispersants, which are the chemicals help in breaking down of oil and methane. The smaller particles of methane caused by the dispersants provided easier fodder for the methanogens.

Conclusion

The methane-consuming bacteria came into the Gulf of Mexico through the ocean, where they exist near the methane-seeping vents. These methanogens metabolized all of the methane in just a few months by utilizing oxygen in the ocean.

Summary Introduction

To describe:

The microbial species that were involved in methane consumption.

Concept introduction:

The most abundant substance released in the British Petroleum oil spill that took place in the Gulf of Mexico in 2010 was methane, which formed a 110-220 yards thick layer in the ocean. This concentration of methane was 10,000-100,000 times more than the normal concentrations. However, the methane concentration reduced to negligible amounts within a few months due to its consumption by methane-consuming bacteria.

Explanation of Solution

One of the methods used to estimate the volume of methane consumed by methanogens involved the introduction of radioactive methane, ethane, and propane to non-polluted samples of water collected from the Gulf.

The microbes that were already present in the water, consumed the radioactive methane, ethane, and propane. As a result, the radioactive carbon atoms got attached to the DNA of these microbes. The radioactive DNA of the microbes was analyzed to confirm the type of microbes that specifically consumed methane. The main consumers of methane were found to be the members of Methylococcaceae, Oceanospirillales, and Cycloclasticus.

Conclusion

After conducting genomic analysis, it was found that the main consumers of methane were the members of Methylococcaceae, Oceanospirillales, and Cycloclasticus.