Oil is formed from hydrocarbons: organic compounds which consist soley of the elements hydrogen and carbon. There are many, many different types of hydrocarbons, all of varying lengths and shapes, and pretty much all of them can in some way be consumed as an energy source by bacteria.
Hydrocarbons, in both ring and chain form, taken from a mix of sources
The general rule is that the shorter and fewer rings present, the more toxic the compound to bacteria (ethanol, for example, is deadly) however there are very few hydrocarbons that some bacteria somewhere won't consume. Like all living organisms, bacteria need a carbon source for energy, and when there are none of the coventional ones around (such as glucose and lactose) many of them will start consuming the ones in oil - crude oil contains a lot of carbon, which is why we burn it for energy in the first place.
Oil-eating bacteria have been found in a huge number of locations as well - seawater, freshwater, groundwater, water containing sludge, and land environments such as silt, soil and sand. They are found in arid deserts o the Middle East (which to be fair is a good place to hang out if you consume oil) and even in ice cores from Antarctica. And rather than being found widespread within seperate species, the capacity for oil consupmtion is often found in many different species within a particular location - in the bacterial world you are more likely to share habits with your nearest neighbours than with your closest relatives.
Using these bacteria for our own purposes, however, is proving slightly more problematic. You can purchse freeze-dried hydrocarbon-degrading bacteria and sprinkle them on your oil slick like minature Captain Planets, but their abilities are currently not nearly as effective as chemical detergents, or physical removal of the oil. This is mostly because these freeze-dried bacteria are specialised lab strains that (much like several of the academics that constructed them...) are often highly unsuited to the real world outside of the safe confines of the lab. Sometimes as well the pollutant is unaccessible to the bacteria, which may be floating on the top of the water while the oil is in droplets underneath the surface.
Looking into the potential of oil-eating bacteria is encouraging though, especially after incidents like the BP oil spill earlier this year. For the oil eating bactera that were hanging around, that must have been a feast day! And even though that event has now been largely forgotten by the media, there will still be coils and dropplets of oil floating around from it, and those will be cleaned up almost exclusively by bacteria.
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Lena Ciric (2010). A natural solution: how bacterial communities can help clean up oil spills Microbiology Today, 229-231
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9 comments:
Ever since the BP oil spill I've been wondering why oil degrading bacteria haven't been used effectively to combat the leaked oil, so thanks for clearig that up! I was wondering, do you have any thoughts on what should be changed in the way bacteria are cultured/engineered, so that they would stand a chance in the real world ? Since bacteria can adapt so quickly, the very act of raising a bacterial strain in the laboratory already introduces changes that make them relatively lazy and spoiled, compared to their wild type cousins.
It's awesome how widespread these species are isnt it?
In the interests of self promotion I wonder if you saw the post below that I wrote at the time of the BP spill?
http://diseaseoftheweek.wordpress.com/2010/06/16/the-wednesday-post-16610/
@Lucas: Engineering tougher bacteria is always difficult, because while you want them to survive for long enough, you don't really want the ethical worries of releasing a load of uber-strong bacteria into the wild.
@disease: LOL I self-promote all the time, don't worry about it :p I think I remember seeing the post, but I'll check it out again.
It's always interesting to me how organisms can evolve to thrive on even the most toxic substances- I ran across a report a while back on a fern which bioaccumulates arsenic, possibly useful for cleaning up mine tailings, etc.
On the other hand, wasn't the bacterial metabolism of oil responsible for the anoxia during the BP spill? A successful bioremediation strategy would have to take that into account, it seems to me.
also ethalon ?= ethanol
@Charlie: GAH yes thanks for catching the mistake, just corrected it. I haven't had a proper look at bacterial treatments during the BP oil spill, but I can easily imagine anoxia being one of the consequences - huge numbers of bacteria in one area may cause problems of their own, even if they are carrying out useful jobs.
Hola, el link que has puesto a twitter no funciona.
Un saludo y felicidades por todos tus artÃculos, son geniales.
@Raven: Thanks! I didn't *completely* understand your comment but thanks for the support and I have fixed the twitter link :)
Paul Stamets has done some really interesting stuff using fungi for bioremediation. Apparently oyster mushrooms just nom down on petroleum if you give them a chance:
http://www.fungi.com/mycotech/petroleum_problem.html
@Lab Rat: Aside from the ethical side of culturing resistant and strong bacteria, I'm wondering whether we can do it at all! To me, domestication (whether it is in the lab or in the farm) always seems to result in organisms that are not as fit to survive in the wild as the original stock.
So my question is whether the act of culturing itself already prevent us from creating über-strong bacteria?
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