Benefits of Bacteria

In these times of interest in ecology, bacteria get high credit for their role in decay, whereby carbon dioxide is returned to the atmosphere and goes through the carbon cycle again. Without bacteria, plant and animal remnants would continually accumulate and perhaps overwhelm the planet. Bacteria are also important as sources of antibiotics. Furthermore, cheeses, acetic acid, vinegar, and various amino acids and enzymes used commercially are produced by bacteria.

Although many types of bacteria cause plant diseases, there is some injustice in the bad reputation of these organisms. Some bacteria, in fact, hold inherent virtues for plants. For example, the bacteria that reside in the root nodules of leguminous plants such as alfalfa, clover, soy bean, and peas can fix (that is, make useful compounds of) atmospheric nitrogen. They convert nitrogen to nitrate, thereby making it available to plants. This is an example of symbiosis. Two soil organisms are valuable in fixing nitrogen: Nitrosomonas, which converts ammonia compounds to nitrates, and Nitrobacter, which converts nitrite to nitrate. Bacteria are also important agents of decay, clearing away dead vegetation and animals and building up the soil.