NCC Microbiology Lecture 1

Microorganisms are organisms that are too small to be seen with the unaided eye.
The term "germ" refers to a rapidly growing cell.

Pathogenic Microbes: A few microorganisms cause diseases.
Decomposition: Microbes decompose organic waste, aiding in nutrient cycling.
Producers in Ecosystems: Microorganisms perform photosynthesis, contributing to ecosystem productivity.
Industrial Applications: Microbes produce chemicals (e.g., ethanol and acetone) and fermented foods (e.g., vinegar, cheese, and bread).
Manufacturing & Medicine: Microorganisms are used to produce industrial products (like cellulase) and medical treatments (e.g., insulin).

Indigo-Producing E. coli: E. coli can be engineered to produce indigo dye from tryptophan.

Understanding microorganisms enables prevention of food spoilage and diseases.
Aseptic techniques have been developed to prevent contamination in labs and medicine.

Scientific Nomenclature: Established by Linnaeus; every organism has two names: genus and specific epithet.
Formatting Scientific Names: Names are italicized or underlined, with genus capitalized and specific epithet lowercase. Names may describe or honor scientists.
- Example: Escherichia coli honors Theodor Escherich and describes its habitat in the large intestine.
- Example: Staphylococcus aureus describes clustered spherical cells with gold-colored colonies.

After the first use, organisms may be abbreviated (e.g., E. coli, S. aureus).

Bacteria: Prokaryotes with peptidoglycan cell walls, reproduce through binary fission.
Archaea: Prokaryotic, lack peptidoglycan, thrive in extreme environments (methanogens, extreme halophiles, extreme thermophiles).
Fungi: Eukaryotes with chitin cell walls, consume organic chemicals, include unicellular yeasts and multicellular molds/mushrooms.
Protozoa: Eukaryotes, absorb or ingest organic chemicals, may be motile.
Algae: Eukaryotes with cellulose walls, perform photosynthesis.
Viruses: Acellular entities consisting of DNA or RNA, require a living host to replicate.
Multicellular Animal Parasites: Eukaryotic organisms, include helminths with microscopic life stages.

Three Domains: Bacteria, Archaea, and Eukarya (which includes Protists, Fungi, Plants, Animals).

Early Discovers: Robert Hooke (1665) suggested that living things are composed of cells. Rudolf Virchow (1858) proclaimed that all cells arise from preexisting cells—forming the cell theory.

Hypotheses: Spontaneous generation suggests life arises from nonliving matter; biogenesis states life arises from preexisting life.
Experiments: Francesco Redi (1668) used sealed jars with meat to demonstrate that maggots do not spontaneously arise. John Needham found that boiled nutrient broth could develop microbial growth, leading to debate. Lazzaro Spallanzani and Louis Pasteur further disproved spontaneous generation.

Initiated with Pasteur's work, leading to discoveries about disease, immunity, and antimicrobial drugs.

Showed microbes cause fermentation and spoilage, and introduced pasteurization as a heat treatment method to kill spoilage bacteria while preserving beverages.

Early Discoveries: Agostino Bassi (1835) linked disease in silkworms to fungus, and Joseph Lister applied this by using antiseptics to prevent infections in surgeries.
Koch's Postulates: Established by Robert Koch in 1876 to prove that specific microbes cause specific diseases.

Edward Jenner (1796) pioneered vaccination against smallpox. Modern chemotherapy involves synthetic drugs and antibiotics to combat infections.

Alexander Fleming discovered penicillin in 1928, which led to the mass production of antibiotics.

Bacteriology, Mycology, Virology, Parasitology: Fields focused on studying respective microorganisms.
Immunology: The study of the immune system and effectiveness against diseases.

Emerging field studying gene inheritance, molecular biology, and genetic modification in microbes, leading to advances in vaccines and crop protection.

Bacteria recycle nutrients essential for plant and animal life and are used in bioremediation processes.

Microbes serve as alternatives to chemical pesticides (e.g., Bacillus thuringiensis). Modern biotechnology utilizes microbes in various production processes for food and chemicals.

Referring to microbes that are naturally present, providing benefits such as preventing pathogen growth and producing essential nutrients.

Microbes form biofilms on various surfaces, complicating infections and treatments.

Occur when pathogens overcome host defenses. Emerging infectious diseases (EIDs) are increasing in incidence; notable examples include Avian Influenza A and MRSA (Methicillin-resistant Staphylococcus aureus).

West Nile Encephalitis: Originated in the West Nile region, spread through birds.
E. coli O157:H7: Toxin-producing strain, significant cause of diarrheal diseases.
AIDS: Caused by HIV, recognized as a worldwide epidemic.