Introduction to Microbiology :
• Microbiology is the branch of science that studies microorganisms, which are
microscopic living organisms such as bacteria, viruses, fungi, and protozoa.
• Microorganisms are present everywhere in our environment, and they play important
roles in various aspects of life, including human health, agriculture, food production, and
the environment.
• Microbiology encompasses several sub-disciplines, including bacteriology, virology,
mycology, and parasitology.
1. Bacteriology:
• Bacteriology is the study of bacteria, which are single-celled microorganisms with a
prokaryotic cellular structure.
• Bacteria have diverse shapes (e.g., cocci, bacilli, spirilla) and can be classified based on
their staining characteristics (Gram-positive and Gram-negative).
• They can have beneficial or harmful effects on human health and the environment.
• Bacteria are involved in processes such as nitrogen fixation, decomposition, and food
fermentation.
1. Virology:
• Virology focuses on the study of viruses, which are tiny infectious agents that can only
replicate inside the cells of other organisms.
• Viruses consist of genetic material (DNA or RNA) surrounded by a protein coat.
• They are responsible for causing various diseases in humans, animals, and plants.
• Viruses have specific host ranges and can undergo genetic mutations, leading to the
emergence of new strains.
1. Mycology:
• Mycology is the study of fungi, which are eukaryotic microorganisms that include yeasts,
molds, and mushrooms.
• Fungi can be either single-celled (yeasts) or multicellular (molds and mushrooms)
organisms.
• They play essential roles in decomposition, nutrient cycling, and symbiotic relationships.
