Coker’s oil spill research focuses on degrading microbials

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James Coker, Ph.D., has spent his adult life searching for the smallest of living organisms that thrive in harsh environments.

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James Coker, assistant professor of biology, hopes to find new microorganisms that will dominate in the carbon-rich environments of the Gulf of Mexico affected by the April 2010 Deepwater Horizon oil spill.

His graduate student work was searching for bacteria in Antarctica, and his post-doctoral work examined an organism that grows in high-salt environments including the Great Salt Lake in Utah and the Dead Sea near Jordan and Israel.

Now he’s in search of microorganisms closer to home. Coker, assistant professor of biology, hopes to find new microorganisms that will dominate in the carbon-rich environments of the Gulf of Mexico affected by the April 2010 Deepwater Horizon oil spill. Coker is part of a consortium of researchers from Alabama State, Auburn University and the University of West Florida that received a $60,000 Small Grant for Exploratory Research (SGER) from Alabama’s Marine Environmental Science Consortium. The study will link ecosystem contamination by oil and dispersants to its effect on prokaryotic microbial communities.

“We’re trying to see how the microbial population has changed and find out what’s there,” Coker says. “We think the oil that was spilled into the Gulf is a natural selector for certain groups of organisms that are able to degrade oil naturally. Therefore the amount of microbes there, or at least the numbers of certain types, should shrink. But certain groups will thrive.”

As an example, imagine that there are 100 groups of microbials in the ocean, 30 of which are predominates. The hypothesis is that now — after the spill — there will be fewer predominate microorganism groups. But the ones that are there and can degrade the oil will be flourishing.

“Certain microbials now have a bunch of food available to them, and they’re all like pigs to a trough,” Coker says. “They’ll run there and eat it all up. And because they have a lot of nutrients, they are able to divide and grow and multiply faster, so there will be hundreds of thousands more of them than everything else.”

The research team will take pre- and post-spill water samples to calculate the number of microorganisms currently there. Coker’s main role is to find the archaeal communities so they can be comparatively analyzed with the bacterial communities, which is the area of research focus for the other investigators. The group will employ technical advances in DNA molecular microbial community analyses — known as denaturing gradient gel electrophoresis (DGGE) and automated ribosomal intergenic spacer analyses (ARISA) — to understand ecosystem response to assaults of this scope and magnitude. They also plan to develop a model for aquatic ecosystem response at its prokaryotic base and provide a generalized approach for further studies of ecosystem response to different stressors.

Coker knows there are three big microbial players — Alcanivorax, Vibrio and Pseudomonas — he expects to see. Alcanivorax is known especially for its ability to degrade oil.

“One of the reasons the dispersant was spread throughout the Gulf after the spill was because it’s thought that it breaks the oil apart well enough to enable these microbes to chew it up and bioremediate it,” Coker says. “The real data behind that is a little bit sketchy. However, we know about Alcanivorax, Vibrio and Pseudomonas, and we know they do all of this on the surface or close to the surface because they need oxygen in order to break apart the oil and to grow. The question is, what’s further down in the water that’s getting rid of the oil — or is there anything getting rid of it? We believe there is, but they haven’t been discovered yet or studied as well as the big three.”

The ultimate goal

The communities of bacteria in the ocean naturally primed to bioremediate or remove the oil work at a much slower rate than researchers prefer.

Coker points to the 1978 Amoco Cadiz oil spill off the coast of France as an example. At the time, it was the largest oil spill of its kind in history. Coker says it took almost a year for the microbes to remove the near 220,000 tons of light crude spilled by the tanker.

“The microbes idea of using all of this oil up is on the scale of months, years and decades,” he says.

That’s one reason why this current research work is important.

The idea of trying to do bioremediation in waters all over the world has been around for a long period of time. One of the first patents taken out on any sort of microbial species was on an organism thought to be good at degrading oil. And spraying oil spills on sand with dispersant has shown that it will help stimulate bioremediation.

Scientists hope to eventually create an environmentally friendly microbe from scratch that will degrade the oil, possibly using it in addition to or instead of a sprayed dispersant like that used in the Gulf spill.

“That’s the long term, ultimate goal — to create a microbe that would take care of all of it,” Coker says. “There are some problems with that. There already are microbial groups there that do this, and they are adapted to live in that environment. So if you’ve got some outsider coming in, they’re probably going to have a harder time out competing the ones that are already using the oil as a food source. There are still many questions, but it’s something many researchers are looking into.”

Funding for the SGER is for one year, and Coker and the other collaborators hope to have their work completed early next year.

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