We can look at reuse and repurpose in two ways. One is more short-term, low cost, but less effective way. In this aspect, individuals reuse the waste materials they have by themselves. For example a housewife reuse a plastic bag again and again to contain the children’s lunch boxes, or students replace the ink tube inside the pen so that they don’t dispose the whole pen after the ink is used up. These are good ideas, but they contribute to reuse and repurpose significantly only if a large amount of people are doing it. As I investigated, however, students that I talked to usually throw away the whole pen, and few people will reuse them. Another way is the more macro, more significant, and usually the evolutionary way. Since genetic engineer science was developed, scientists have never been bored playing around bacteria. Recent example for bacteria’s contribution to the environment was the British Petroleum issue in the Mexican Gulf. Scientists used modified bacteria to consume the leaked petroleum as food, and produce less environmental-harmful products. This idea can be  apply to reuse other substance as well. In fact, recent research in the U.S. Department of Energy shows a substantial progress in finding bacteria that “eat” paper. The University of Wisconsin professor Mark McBridge who helped in the Department of Energy contributed greatly on the discovery and modification of the bacteria C. hutchinsonii, which take cellulose as food and produce ethanol as the end product. This greatly helps the development of reusing and repurposing of the paper, which is thought to be a non-reusable material a few years ago.  These kind of methods solve problems from the root, and they reuse and repurpose materials in a much broader aspect.