Oil-eating microbes may not be all they’re cracked up to be

Brett Michael Dykes
National Affairs Reporter
The Upshot

Remember the mighty oil-eating microbes, aka marine bacteria, that commentators from the White House on down hailed  as a major natural weapon in combating the Gulf oil disaster? Well, the recent discovery of thick layers of oil on the Gulf floor, in addition to the detection of massive underwater oil plumes, aroused some suspicion that the work of the Gulf microbes had been a bit overhyped. Now a new study finds that the microbes may have mainly consumed gases seeping from BP's busted well, as opposed to the actual oil that leaked into the Gulf.

As the Los Angeles Times' Eryn Brown reports, a study published in the journal Science finds that "bacteria that attacked the plumes of oil and gas resulting from the Deepwater Horizon gusher in the Gulf of Mexico mainly digested natural gas spewing from the wellhead — propane, ethane and butane — rather than oil."

The paper's lead author — David L. Valentine, a professor of microbial geochemistry at UC Santa Barbara — told Brown that the oil-gobbling properties of the microbes have been grossly overstated.

"It's hard to imagine these bacteria are capable of taking down all components of oil," Valentine said. "These stories about superbugs taking down all the oil — it's more complex than that."

What's more, some experts suggest that the proliferation of the bacteria may be causing health issues for Gulf Coast residents. Writing on The Huffington Post, Riki Ott — a marine toxicologist — says that the bacteria might be responsible for an outbreak of mysterious skin rashes local physicians have lately noted.

She writes:

There are two distinct types of bacteria based on the structure of their cell walls. Gram-positive bacteria have a single-membrane cell wall, while Gram-negative bacteria have a double-membrane cell wall. Methicillin-resistant Staphylococcus aureus (MRSA) bacteria are "Gram-positive," while the oil-eating bacteria are Gram-negative.

But! A component of the double-membrane cell-wall structure of Gram-negative bacteria can irritate human skin, causing inflammation and activating the immune system. In other words, oil-eating bacteria, just because they are Gram-negative, can cause skin rashes. In the case of Alcanivorax borkumensis, the reaction can erupt on the skin like MRSA infections.

To make things a little scarier, some of the oil-eating bacteria have been genetically modified, or otherwise bio-engineered, to better eat the oil — including Alcanivorax borkumensis and some of the Pseudomonas.

Ott says that she's spoken to numerous Gulf residents and tourists who have experienced everything from rashes to "peeling palms" after coming in contact with water in the Gulf.