The uniqueness of microbial groups
Among a large number of microorganisms, there are seven macro groups with hundreds of thousands of representatives. These include bacteria, archaea, algae, protozoa, fungi, viruses, and parasitic helminths. Despite their microscopic size, each of the groups described represents a unique biological diversity and is therefore identified as a separate cohort. From all groups of microscopic organisms, representatives of the bacterial and archaean world do not have a nucleus, for this reason, bacteria and archaea are considered prokaryotic cells. However, other membrane organelles, such as mitochondria, are not included in such cells. In addition, these two groups are the most common classes of living organisms, and their habitats are represented by all possible options, from reservoirs to boiling volcanic vents. Some of the bacterial representatives demonstrate parasitic properties such as C. tetani, B. burgdorferi, and S. typhi (1a The Main Themes). At the same time, archaeas have unique biochemical properties, which allows them to use chemical reserves as energy sources. The representatives of this group can be Methanogens and Haloarchaeas.
Moreover, parasitic properties are presented at a group of helminths — these are microscopic worms, which have a variety of forms that cause damage to animals. Compared to other groups of microscopic forms, helminths can be considered the most progressive because they have sexual dimorphism and a complex body. Trichinella is a parasite for mammals by settling in the small intestine and Fluke parasites in animals and snails.
Other groups of microorganisms, except for viruses, are considered eukaryotes because their cells have a formalized nucleus. Viruses are not living in nature and represent integration between inanimate objects and organisms, which is their main feature. The effect is simple particle structure — they do not have most of the known organelles and the capsid contains only genetic material (Moelling and Broecker 2). Well-known representatives of viruses are Tobacco mosaic virus, Ebola virus, and Coronavirus.
Microscopic fungi are beneficial cultures of living organisms for humans: Penicillium and Saccharomyces are used in the production of medicines and culinary products. Fungi do not have chlorophyll, but the cellular structure and features of biochemical processes allow them to correlate with animals and plants simultaneously. Unlike other representatives of microorganisms, fungi are unable to move actively but lead an attached lifestyle.
Among all groups, microscopic algae — photosynthesizing plants of the simplest form — stand out especially. Euglena, a transitional form between animal and plant, has a mixotrophic feeding. The majority of algae move with the help of flagellates or cilium. Congestions of microscopic algae are found in glaciers, in snowy areas, in damp soils, but most of them inhabit water bodies.
The remaining class of microorganisms is protozoa: as a rule, this group collects creatures on the principle of residue, so representatives of the simplest are most diverse. Vorticella has the shape of a bell and is attached to crayfish covers, while Paramecia have cilium that actively moves around the water column. The simplest are usually predators, and their characteristic lifestyles are individual or colonial.
The Golden Age of Microbiology
Since Leeuwenhoek first discovered living microscopic organisms, research into the smallest cells has begun to gain momentum. Simple observation of microorganisms shifted to predicting their properties and characteristics and then to conscious editing to create economically important forms (1b Main Themes). Thus, the science of biotechnology was born, aimed at using biological systems in human activity. The father of biotechnology development can be rightfully considered Edward Jenner, who created the vaccine against smallpox. There is a legend that the young boy Edward, interested in the medical sciences, was approached by a dairymaid and asked about the ulcers that appeared on her body. Jenner assumed it was smallpox, but the milkmaid answered that she could not get sick because she had recently suffered from cowpox. This reaction shocked the boy, and he decided to look into the matter. This legend may be fiction, but it does not negate the fact that Jenner had the intention of developing a cure for this disease. The revolutionary idea he proposed was that a person who had contracted cowpox was not exposed to a more serious type of viral infection. Jenner decided to carry out a risky experiment in which he initially infected an eight-year-old boy with cowpox, and a few days later with smallpox (Morabia 255). As a result, the child was resistant because his immunity had already developed antibodies to the disease, and Jenner’s work became a source of vaccines against hundreds of infections.
Elizabeth Bugie was another researcher who made a useful contribution to microbiology. In particular, the woman studied soil bacteria to find antimicrobial agents to combat plant infections. In 1944, during a series of laboratory experiments, Bugie accidentally discovered the fascinating effect of Gram-positive S. griseus — they produce a metabolic product with antimicrobial action against M. tuberculosis (Elizabeth Bugie). This is how the first milestones in antimicrobial research were reached and how a branch of medicine aimed at combating tuberculosis has developed.
Rebecca Lancefield’s classification helped to understand the existing diversity of microscopic organisms. The researcher has devoted her scientific career to an in-depth study of the structure of cell walls of streptococcal bacteria: she found that there are differences in the carbon composition of antigens (Rebecca Lancefield). Thus, were not only developed a fundamentally new concept of serological classification, but also found that there are several pathogenic forms of bacteria causing scarlet, erysipelas, and sore throat. Lancefield has been awarded the title of President of the American Immunologists Association for its achievements in microbiology.
Works Cited
“1a The Main Themes of Microbiology.” Section Biol 004 or 103. PowerPoint Lecture.
“1b Main Themes of Microbiology.” Section Biol 004 or 103. PowerPoint Lecture.
“Elizabeth Bugie.” Britannica, n.d., 2020. Web.
Moelling, Karin, and Felix Broecker. “Viruses and Evolution – Viruses First? A Personal Perspective.” Frontiers in Microbiology, vol. 10, 2019, pp. 1-13.
Morabia, Alfredo. “Edward Jenner’s 1798 Report of Challenge Experiments Demonstrating the Protective Effects of Cowpox Against Smallpox.” Journal of the Royal Society of Medicine, vol. 111, no. 7, 2018, pp. 255-257.
“Rebecca Lancefield.” Britannica, n.d., 2020. Web.