Bacteria (from the Latin word bacterium; plural: bacteria) are a group of organisms that do not have a cell nucleus membrane. These organisms belong to the domain of prokaryotes and the size is very small (microscopic), as well as having a large role in life on Earth. Several groups of bacteria known as the causative agent of infection and disease, while other groups can provide benefits in the field of food, medicine, and industry. Bacterial cell structure is relatively simple: no nucleus / nucleus of the cell, the cell's skeleton, and other organelles such as mitochondria and chloroplasts. This is the basic difference between prokaryotic cells with eukaryotic cells are more complex.
Bacteria can be found almost everywhere: in soil, water, air, in symbiosis with other organisms as well as parasitic agents (pathogens), even in the human body. In general, bacteria-sized 0.5-5 lm, but there are certain bacteria that can be up to 700 lm in diameter, ie Thiomargarita. They generally have a cell wall, such as plant and fungal cells, but with a very different precursor (peptidoglycan). Some types of bacteria are motile (able to move), and its mobility is caused by the flagellum.
Bacteria are microscopic organisms. This causes the organism is very difficult to detect, especially before the invention of the microscope. It was only after the 19th-century science of microorganisms, especially bacteria (bacteriology), began to develop. Along with development of science, many things about the bacteria have successfully traced. However, this development is inseparable from the role of a variety of important figures such as Robert Hooke, Antoni van Leeuwenhoek, Ferdinand Cohn and Robert Koch. The term bacterium was introduced at a later day by Ehrenberg in 1828, derived from the Greek word βακτηριον (bakterion) which means "little sticks". Knowledge of the bacteria growing after a series of experiments conducted by Louis Pasteur, who gave birth to the branch of microbiology. Bacteriology is the branch of biology that studies microbiology bacteria.
Robert Hooke (1635-1703), a mathematician and a British historian, wrote a book in 1665 titled Micrographia which contains the results of observations made using a simple microscope. However, Robert Hooke still can not menumukan structure of bacteria . In his book, illustrated his findings regarding fungus fruiting bodies. However, the book that is the source of the initial description of the microorganisms.
Antoni van Leeuwenhoek (1632-1723) lived in the same era by Robert Hooke in which microscopy is still very modest. Inspired by the work of Robert Hooke, she makes her own design with a microscope is excellent for observing these microscopic creatures in a variety of media experienced in 1684. Antoni van Leeuwenhoek discovered bacteria successfully for the first time in the world in 1676. The findings sent to the Royal Society of London which was then published in 1684. This discovery immediately got a lot of confirmation of other scientists. Since then, not only bacteria but also the science of microorganisms in general began to grow.
Ferdinand Cohn (1828-1898) was a botanist nationality Breslau (now Poland).The result of many discoveries about the range of bacteria that are resistant to heat. His interest in this bacterial group pointed to the discovery of a group of bacteria producing endospores that are resistant to temperature high. Ferdinand Cohn was also successfully explains the life cycle of the bacterium Bacillus which also explains why this bacterium is resistant to heat. Furthermore, he also made a simple basic classification of bacteria and developed several methods to prevent contamination of bacterial cultures, such as the use of cotton as a cover on pumpkin drinks, erlenmeyer, and test tubes. This method was later used by other scientists, Robert Koch.
Robert Koch (1843-1910), a physicist nationality German, do a lot of research on the disease caused by a bacterial infection. Scientists initially studied anthrax attacks that many farm animals. The disease is caused by Bacillus anthracis, one bacterium producing endospores. Robert Koch was also the first man to successfully obtain pure isolates of Mycobacterium tuberculosis, the bacterium that causes tuberculosis. Based on two studies of this disease, Robert Koch successfully made of Koch's postulates, a theory regarding specific microorganisms for disease specifics. He also managed to find a method to obtain pure isolates of bacteria. Another discovery is the use of solid culture media for growing the bacteria in their natural habitat luat. At first he used a piece of potato and then developed using nutrient gelatin. The use of nutrient gelatin still has a lot of shortcomings, which in turn is replaced by its use in order to (a type of polysaccharide) was initiated by the wife of Walter Hesse who also worked with Robert Koch.
No comments:
Post a Comment