Cleaning with Bacteria
Mention bacteria, and people are likely to conjure up images of unpleasant, disease-causing microorganisms. Yet bacteria do more than cause food poisoning and skin infections. Most are harmless to humans, and some are even necessary for our survival. Without thinking about it, we rely on one of their major characteristics: the capability to break things down. Bacteria degrade the garbage we dump every day; they degrade the leaves that plants drop before winter; and they degrade animal feces. If it were not for the action of bacteria, those substances would remain in their original condition forever, and their contents would not be available for recycling and reuse by other living things. Researchers at various institutions, including the University of Alaska Fairbanks, have paid attention to this characteristic of bacteria and have started research on the creatures to see if they can be used to clean up our environment.
Cleaning up wastes in the environment by using bacteria is called bioremediation. Researchers are working on bioremediation of crude oil, cyanide, polychlorinated biphenyls (PCBs), methyl mercury, and various other hazardous industrial wastes in the environment. Bioremediation has been applied in Alaska, most conspicuously to help clean up oil spilled from the Exxon Valdez in 1989. By releasing specific fertilizers in Prince William Sound, researchers were able to enhance the growth of indigenous bacteria that can degrade crude oil. This effort was discussed (among other places) in an article by J.E. Lindstrom and colleagues that appeared in a 1991 issue of the journal Applied Environmental Microbiology. The researchers believe the results demonstrated the feasibility of bioremediation to clean up oil released in the environment. Since oil production is our major industry, Alaskans stand to benefit significantly from development of this technology.
Another substance that researchers are trying to clean up with bacteria is PCB. PCB was a common and extremely useful industrial chemical before its capacity to cause cancer was recognized. Now banned, PCB does not degrade easily, so significant amounts of the compound still exist in the environment. Sometimes it's in truly dangerous places: the contamination of dairy products with PCB is a national concern. Since natural bacteria aren't very effective at degrading this compound, researchers are looking into genetically engineering bacteria for the job. They will extract genes from bacteria with any ability to degrade PCB, study the genetic information to ascertain which genes produce the required ability, then amplify the desired genes and reinsert them in the bacteria in the hopes of making supermicrobes capable of truly breaking down PCB.
Researchers are also working on bioremediation of cyanide, a toxic compound but one important in an effective method for extracting gold from its ore. Though studies of using bioremediation to clean up cyanide are still in an early stage, the importance of gold mining in Alaska makes this a technology that bears watching.
So it looks as if bioremediation of wastes could be of significant value to our society. This is true especially for Alaska, where a significant amount of unspoiled (and as yet mostly unspilled-upon) territory remains. But bioremediation is no magic bullet to shoot down our waste problem. For example, we have to evaluate carefully the long-term effects of releasing fertilizers or genetically engineered bacteria into the environment. The bacteria must be monitored to be sure they do not release new toxins; the effects of fertilizers must be observed to be sure they do not disturb other organisms. Releasing genetically engineered organisms raises serious ethical questions
By their efforts, scientists have increased the number of options we have for courses of action to clean up our environment. It is our responsibility to make the effort to learn more about these options.
