The Impact of Microorganisms on Human Affairs
What is microbiology? Microbiology is the study of microorganisms or microbes. The word micro means small in Greek, implying that microbes are very minute or small life forms that cannot be seen with just the naked eye. One would need a microscope to see these small life forms. Microbes are everywhere and have a large impact on the world. It all started when one of the most important discoveries in history was made in 1665. Englishman, Robert Hooke discovered “little boxes” or “cells” in a slice of cork through the microscope and explained that these were life’s smallest structural unit (Tortora et al, 2010). This event marked the beginning of the cell theory, that all living things are composed of cells. As expected in the scientific world, a new finding leads to a cascade of experiments to expand on the newly discovered facts. This was shown when Anton Van Leeuwenhoek made the first observation of live microbes though a microscope that he designed himself. Van Leeuwenhoek used rain water, his feces, and his teeth scrapings to make observations from the microbes. For a few years after Van Leeuwenhoek’s discoveries the majority of the world believed that microorganisms spontaneously generated, which means that life forms came from nonliving matter such as toads and mice (Tortora et al, 2010). It was not until the discoveries of Louis Pasteur in 1861 that the theory of spontaneous generation was challenged and the call theory was confirmed. Pasteur resolved this issue by creating experiments demonstrating that microbes are present in the air and can contaminate sterile solutions, but the air itself cannot create microbes. The experiments contained beef broth in several flasks. Some were sealed after being boiled and the rest were kept open after they were boiled. The flasks that were kept open in the air accumulated microbes whereas the flasks that were sealed did not. Pasteur then followed up his first experiment by doing another experiment. He used the same principle, except he used a flask with an S-shaped neck that allowed air to pass through but the design of the flask trapped any bacteria in the neck. After boiling and allowing the broth to cool, there were no signs of microbial growth (Tortora et al, 2010). The final step toward identifying as a source of disease came with the findings or Robert Koch in 1881. Koch, using a series of observations, later known as Koch’s Postulates, found that specific microbes cause specific diseases. He proved that bacteria causes disease by observing animals for the presence of Bacillus anthracis, the causative agent of anthrax. He found that this bacterium was in the blood of the cow that had died from anthrax. Koch then retrieved the bacteria from the cow, grew it on pure culture, injected it into a healthy animal, and waited to see if the healthy animal had the same results. Like he thought, the animal became infected and Koch was able to isolate the same organism from the newly diseased animal. This process is still used today in the detection of microorganisms being responsible for causing disease (Tortora et al, 2010). These scientists and their experiments laid the foundation for the discovery of an unknown world and quickly became life changing.
Before one can understand the impact of Microbes on human affairs, one must be aware of the types of microorganisms there are in this world. Microbes consist of six groups: Bacteria, Archaea, Fungi, Protozoa, Algae, and Viruses. These groups are very different but are similar in that they are small in size. Furthermore these groups are divided into two different groups: Eukaryotic and prokaryotic, excluding viruses. Fungi, Algae, and Protozoa are classified as Eukaryotic which means they are multicellular and include a nucleus and membrane-bound organelles. Bacteria and Archaea are classified as prokaryotic in which they are unicellular and do not have a nucleus nor membrane-bound...
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