Microbiology - History and Scope

Microbiology - History and Scope

• Microbiology is the study of microorganisms, typically smaller than 1mm in diameter, which usually requires magnification to be seen clearly.
• Microbes are essential to life on Earth, having a variety of roles in the food, ecosystem, and pharmaceutical industries.
• The human body carries more microbes than human cells.
• The human mouth contains approximately 500 different bacterial species.
• The largest bacteria (e.g., Thiomargarita namibiensis and Epulopiscium fishelsoni) are visible through the naked eye.
• Mycoplasmas are the smallest known bacteria.
• In 1918, the influenza virus killed more people than those who died in World War I.
• Microbes produce half of the Earth's atmosphere oxygen.
• Microbes have intricate processes, structures, and behaviors, much like other animals.
• Without microbes, life on Earth cannot be sustained.

Key Figures in Microbiology History

• Robert Hooke (1635-1703): Made significant discoveries in the 17th century, including early microscopes, and observed plant cells and some microbes.
• Antonie van Leeuwenhoek (1632-1723): Designed early microscopes, essential for viewing tiny microbes and is considered to be the first to observe microscopic cells.
• Élie Metchnikoff (1845-1916): Identified the immune system's role in fighting infection in animals.
• Paul Ehrlich (1854-1915): Developed a "magic bullet" (salvarsan) to fight syphilis, marking an early step in chemotherapy.
• Gerhard Domagk (1895-1964): Discovered the sulfa drug, prontosil, the first successful drug against a variety of bacterial infections.
• Sir Alexander Fleming (1881-1955) and Selman Waksman (1888-1973): Discovered penicillin and other antibiotics, profoundly impacting medicine and public health.

Branches of Microbiology

• Bacteriology: Studies bacteria, with medical, agricultural, and biotechnological specializations.
• Mycology: Studies fungi, similarly having medical, agricultural, and biotechnological specializations.
• Protozoology: Investigates small, animal-like single-celled organisms (like amoeba) and many disease-causing parasites.
• Phycology: Studies algae.
• Parasitology: Examines small animals acting as agents of disease—including microscopic worms and protozoan pathogens.
• Immunology: Often taught and researched in microbiology.

Importance of Microorganisms

• Food industry and beverages: Microbes are used to produce various items such as curd, wine, beer, and bakery goods.
• Microflora: Microbes in the digestive system aid digestion, produce essential vitamins (like vitamin K), and combat other harmful microbes.
• Pharmaceutical industry: Microbes contribute to creating antibiotics.
• Environment: Microbes play a crucial role in soil fertility and environmental cleaning.

Discovering Microorganisms

• 1635-1703: Robert Hooke created early descriptions of microbes.
• 1676: A. Leeuwenhoek observed and accurately described microbes.
• 1828-1898: F. Cohn detailed the life cycle of bacillus and other microbes.
• 1884: Chamberland devised a filter for identifying viruses.
• 1898: Loeffler and Frosch identified a filterable agent causing foot-and-mouth disease.
• 1898-1900: Beijerinck identified tobacco mosaic virus.

Additional Questions

• Are microbes such as bacteria mostly beneficial or harmful? Explain. (Answer not provided in given text.)