Bacteriology is the science which has to do with the study of bacteria. The bacteriologist finds out what the different kinds of bacteria are, how they grow, and what they do. Man become interested in studying bacteria when he discovered that they caused important changes in himself and the world around him. Some of these changes were fermentation, decay and diseases. Fermentation and decay are chemical changes in non-living matter like food.
The two men who studied bacteria after that first discovery proved that the same bacteria always caused the same kinds of fermentations and diseases. A large part of the science of bacteriology has been the development of correct ways of studying and identifying bacteria so that they could be easily recognized. There are ways to separate different kinds and grow each kind alone in a special food. As the bacteriologist determines what they do to food, he learns what they can do to live plants and animals. Sometimes, the scientist uses live animals to help him learn about the diseases bacteria causes.
By understanding bacteria, man can stop their growth or raise new cultures according to his needs. This knowledge is useful in preventing food spoilage and disease, fertilizing the soil or preparing food products.
Great people behind the discovery of bacteria
Anton Van Leeuwenhoek (1632-1723) – was the first person to make a lens strong enough to observe bacteria.
Louis Pasteur (1822-1895) – it was his discovery that changed the belief that diseases were caused by evil spirits or angry gods and that epidemic is uncontrollable. Pasteur discovered that the microorganisms that Leeuwenhoek studied in his microscope were the causes of fermentation and decay and he went to prove that they could cause diseases in the same way.
Pasteur’s studies also helped the theory believed by most people at the time that some living things came into being suddenly out of non-living matter. This theory was called Spontaneous Generation. He proved by careful experiments thatbacteria always from other living bacteria.
Robert Koch (1843-1910) – he discovered the bacteria that cause anthrax in cattle and tuberculosis in man. A pure culture is one kind of bacteria growing by itself. The whole colony of bacteria in a pure culture is descended from a single cell. One can be sure he is studying the habits of a certain kind of bacteria only if he studies that kind alone without interference from others. Koch discovered that in a jelly-like substance or culture medium called agar, bacteria could be separated and then held fast while they developed into pure colonies.
Using pure culture methods and Koch’s rules, bacteriologists isolated and identified many disease-causing organisms. It has been possible to develop vaccines, serums, and antitoxins which give people artificial immunity against these diseases. Thus, when man understands his world he became able to control and change it to make life safer and easier. As a result of the work of bacteriologists, he knows how to prevent disease by keeping foods and water supplies free from harmful bacteria (germs), and he can use vaccines and other methods to control disease.
How do bacteria help humans?
Not all bacteria are harmful. Most are harmless and some are helpful to man. Certain bacteria get their food by causing the decay of dead plants and animals or animal wastes. By breaking down this dead matter they release food for themselves and at the same time return to the soil valuable food elements like nitrogen and minerals in forms which growing plants can use.
Other bacteria take free nitrogen from the air and “fix” it so plants can use it. Since all man’s foods are plants or dependent on plants, these bacteria perform a vital service. Some bacteria live within the intestines of humans and animals and help them in the digestion of food.
Gramicidin is a substance produced by soil bacteria which kills other bacteria, such as the pneumococcus, staphylococcus, or streptococcus. There is a whole area of bacteriology dealing with foods. Not only has the bacteriologist learned to prevent spoilage in food by destroying harmfulbacteria to make certain foods. Foods such as cream, cheese, and some meats depend on bacterial action to ripen them. Pickles, vinegar, and sauerkraut are made by bacterial action on other foods. It may well be that in the not to distant future microorganisms themselves will become part of the diet of man.
There are many kinds of bacteria that have been studied very little, and there are undoubtedly hundreds still undiscovered. Man may find that bacteria are tied up with human welfare in many other ways. Bacteriology in the future will be concerned with this and with studying the bacteria on other planets.