Biology of Microbial Cells Lecture 1

Study Notes

Microbiology is the study of very small living organisms, including bacteria, algae, protozoa, fungi, and viruses.
Microorganisms are required to be studied using a microscope.

Microorganisms (MOs) include bacteria, algae, protozoa, fungi, and viruses.
Viruses are infectious agents or particles.
Only 3% of known microorganisms are pathogens, while 97% are non-pathogens, and 87% are beneficial.
Indigenous microflora or microbiota refers to microorganisms that are naturally present in a specific environment.
Microorganisms are ubiquitous, meaning they are present everywhere.

The concept of microorganisms was initially suggested by the spread of diseases, which implied the existence of invisible, transmissible agents of infection.
Antony Van Leeuwenhoek referred to microorganisms as "animalcules".
The theory of spontaneous generation suggested that living organisms arise from decomposing organic matter, but this was later disproven.

Louis Pasteur showed that microbes cause fermentation and spoilage, disproved spontaneous generation, and developed aseptic techniques.
Pasteur's work laid the foundation for modern microbiology.

Pasteur's experiment demonstrated the role of microorganisms in fermentation and spoilage.

The germ theory of disease states that diseases are transmitted by microorganisms from a diseased to a healthy person.
Examples of diseases caused by microorganisms include diphtheria (caused by Corynebacterium diphtheriae) and tetanus (caused by Clostridium tetani).

Robert Koch developed solid growth media, pure culture techniques, simple stain techniques, and aseptic lab techniques.
Koch isolated bacteria as causative agents for anthrax.

Koch's Postulates are a series of experimental steps to show that a specific organism causes a specific disease.

Ferdinand Cohn discovered and described endospores.
The term "sterile" means the complete removal of all life forms, including endospores.

Basic Microbiology: classifications, metabolism, metabolic pathways, nutrition, growth, and its requirements.
Medical Microbiology: human pathogens.
Industrial Microbiology: microorganisms used to obtain industrial products.
Pharmaceutical Microbiology: production of drugs, enzymes, solvents, alcohols, etc. by microorganisms.
Agricultural Microbiology: microorganisms used as biofertilizers and biocontrol agents of plant pathogens.
Environmental Microbiology (Microbial Ecology): pollution of soil, air, and water, and biodegradation of toxic chemicals by various microorganisms.