Microbiology.

ROLCAM · Posted: Thu Sep 13, 2007 10:20 am Post subject: Microbiology.

Microbiology, is the study of microscopic organisms. These organisms are sometimes called microbes. They include algae, bacteria, molds, protozoans, viruses, and yeasts. Microbiologists also study such tiny infectious particles as prions, viroids, and plasmids.

Many biologists specialize in the study of certain kinds of microorganisms. For example, bacteriologists work with bacteria, mycologists are concerned with fungi, and virologists study viruses.

Microorganisms. Nearly all microorganisms measure less than 4/1,000 inch (0.1 millimeter) across. Many microorganisms must be studied with microscopes that magnify objects at least 1,000 times. Most viruses, plasmids, prions, and viroids are so tiny that they can be seen only with electron microscopes that magnify many thousands of times.

Viruses are called acellular microorganisms because they do not have true cell structures. All other microorganisms are cellular. They have cell membranes, cytoplasm, and either a nucleus or a nucleoid. Bacteria are the smallest single-celled organisms. The smallest bacteria may be as small as 4/10 of a micrometer (a micrometer is 1/25,400 inch, or .001 millimeter). About 10,000 small viruses could be packed into a cell the size of one of these bacteria. Over a billion of these tiny cells could be packed into one of the largest microbial cells--the cells of a certain algae.

Fields of microbiology. Many microbiologists study the relationships between microbes and human beings, animals, and plants. Medical microbiologists investigate the role of microorganisms in human and animal diseases and search for ways to prevent and cure these diseases. Dental microbiologists are concerned with the microorganisms found in the mouth, especially their role in tooth decay. Agricultural microbiologists study plant diseases, the role of microorganisms in soil fertility, and spoilage of agricultural products by microorganisms. Industrial microbiologists use microorganisms to produce such products as alcoholic beverages, amino acids, antibiotics, citric acid, and vitamin C. General microbiologists study the basic features of microorganisms, including ecology, genetics, metabolism, physiology, and structure.

Microorganisms also play an important part in sewage treatment and pollution control. Some microorganisms, such as algae and bacteria, are being grown experimentally for use as food. Yeast is used as an ingredient in a variety of foods. It adds flavor and increases the nutritional value of certain foods, such as potato chips. Advances in genetic engineering also have made microbes more useful to people. Scientists can develop new microbes by transferring genes from one organism to another or by making desirable changes in specific genes.
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Roland Camilleri

Moderator

Sydney , Australia.