What association usually comes to mind when we think about bacteria?? Most likely at the mention of bacteria, we think of germs and of disease and of how we need to sterilize to keep them from harming us. Most of us, however, tend to ignore the fact that although humans do their best each day to cook and sterilize away the tiny micro-organisms known as bacteria, there are literally thousands and thousands that surround and affect our lives uniquely every day. Were it not for these very useful bacteria, the world would definately not be as we see it today, for it is upon these essential monerans that every living organism on earth has come to depend. Despite the common, and valid association of bacteria to deadly germs and disease, bacteria also have other very important roles in nature. Not only do these tiny organisms help fight desease in humans, but they also maintain the fragile balance on earth and are often used in the chemical and mining industries. These are just a few of the positive influences that certain bacteria have on the lives of living organisms.
The largest, most significant role in which bacteria are involved is the decomposition of waste materials on earth and in the process, the maintaining of a balance in nature. Without these saprophytic bacteria, the remains of dead organisms and plants would not decay and the waste would accumulate so fast that it would soon interfere with the life of new generations. After breaking down the compounds found in organic waste materials into simpler substances, the bacteria also enrich the soil by returning these minerals to it, rendering it useful once again for plants and animals. During this natural recycling process, the saprophytic bacteria release carbon dioxide into the air which is an essential substance for the growth of plants, and consequently for the survival of all living things.
Although bacteria are known to cause harmful diseases in humans and other organisms, it is a seldom recognized fact that bacteria actually help us fight the very disease they cause. It is through vaccines and antibiotics that medical science has made use of both the pathogenic bacteria and their toxins. Scientists have found that when bacteria are killed and injected into the human body, the body produces the same antibodies that it forms to protect itself against live bacteria. This process, which is called vaccination, serves as a preventative inoculation for the kind of disease-causing bacteria from which the vaccine was made. Today, humans receive vaccinations for bacterial diseases such as Tuberculosis, Diptheria and Tetanus.
Another way in which bacteria help fight disease is through Antibiotic secretion, where some micro-organisms secrete germ-fighting drugs called antibiotics. The bacteria belong to the genus Streptomycin and produce antibiotics such as Bacitracin, Polymyxin and Erythromycin. Although the best-known antibiotic, Penicillin, is not made by bacteria, but rather by mold, the soil-inhabiting Streptomycin genus contains organisms which are mold-like in that they possess many characteristics of molds.
Even though bacteria have taken on a huge enough role on their own in the natural environment, humans have adapted some of these monerans for more specialized purposes still. Many bacteria produce chemical changes which are part of the process called fermentation and are used in the manufacture of fermented foods and beverages such as buttermilk, yogurt and sour cream. In the fermentation of these foods, the bacteria change mild sugar into acid in much the same way that plant sugars are turned into acids when corn is changed into silage by other bacteria. The process of fermentation is also important in the chemical industry. For example, the solvents butyl alcohol and acetone are formed by Clostridium bacterium. Another useful substance, Dextran, which is used as a blood-plasma substitute, is made by a type of Leuconostoc bacterium from sucrose.
There are countless ways in which humans and all organisms depend on the microscopic, yet extremely effective organisms known as bacteria. From the fighting of disease and the forming of symbiont relationships to the removal of waste spills, there are many bacteria in the moneran kingdom without which life on earth would not exist! Who would have guessed that such a huge job in the maintaining of the world would rest on the shoulders of an organism measuring as little as 1 micron long? Perhaps, because of their size and our attempts to destroy them, we do not notice these tiny little creatures on a day to day basis. However, we just have to look around us to understand the important role they play and appreciate the positive purposes they have on earth.