During the twentieth century, scientists discovered many innovative ways to use germs to make people's lives better. Germs are now regularly used to treat sewage and to control insects, and they are also used in the mining of uranium and copper. In addition, researchers are experimenting with using germs to clean up disastrous oil spills. In other experiments, germs are being tested on plants and crops to make them more resistant to disease. Scientists are constantly working to improve and expand these and other germ-based technologies.

Treating Sewage with Microbes

Sewage treatment is one of the largest and most widely used of these germ-based technologies. Sewage is the mixture of water and solid waste materials that people routinely discard each day, including all of the substances that go down toilets as well as through bathtub, sink, and street drains. The...