PRELIM | 1st Semester
Module #1.1 : BRIEF HISTORY OF MICROBIOLOGY
Lecturer(s): [Professor’s Name]
HISTORY OF MICROBIOLOGY
OUTLINE
Early Year of Microbiology
Lesson 1: History of Microbiology
●​ Antoine van Leeuwenhoek
●​ Robert hooke
●​ Francisco redi
○​ Redi Experiment
●​ Louis Pasteur
●​ Robert Kooch
●​ Joseph Lister
●​ Edward Jenner
●​ Alexander fleming
●​The
early
years
of
microbiology
(1600s–1800s)
transformed
invisible
“animalcules” into a scientific reality,
replacing
myths
like
spontaneous
generation with germ theory, and laying the
foundation for modern medicine, public
health, and biotechnology.
ANTOINE VAN LEEUWENHOEK 1663-1723
●​Father of Microbiology
●​ Discovery:
First
to
observe
living
microorganisms Used handcrafted simple
microscopes with lenses far more powerful
than others of his time. (called them
“animalcules”)
○​ First specimen observed: from sewage water,
later also observed rainwater, saliva, blood
cells, and plaque from teeth.
●​ Function : Opened the unseen world of
microbes to science. Proved that life exists
beyond what the naked eye can see.
●​ Relevance : His work laid the foundation of
microbiology as a science.
○​ Inspired the development of the germ
theory of disease (later by Pasteur & Koch).
○​ Modern microbiology, medicine, and
biotechnology still build on his pioneering
observations.
ROBERT HOOKE 1635-1703
OVERVIEW OF MICROBIOLOGY
What is Microbiology
●​Microbiology is the branch of science that
studies microorganisms that are too small to
be seen with the naked eye.
●​ These included bacteria, viruses, fungi,
protozoa, and microscopic algae
●​ It examines structures, physiology and their
roles in health, disease and the environment
BRANCHES OF MICROBIOLOGY
●​Microbe-Centered: Focuses on types of
microbes.
○​ Bacteriology: Bacteria and archaea
○​ Phycology: Algae
○​ Mycology: Fungi
○​ Protozoology: Protozoa
○​ Parasitology: Parasitic protozoa and
animals
○​ Virology: Viruses
●​ Process-Centered: Focuses on microbial
functions and interactions.
○​ Microbial metabolism: Chemical
reactions in cells
○​ Microbial genetics: DNA and RNA
functions​
Environmental microbiology: Microbe
interactions with each other and their
environment
●​ Applied Microbiology: Uses microbes for
human benefit or disease control.
○​ Medical Microbiology: Studies
disease-related aspects such as immunity,
disease spread, causes, infection control,
and drug treatment.
○​ Applied Environmental Microbiology:
Uses microbes for pollution control, public
health, and agriculture.
○​ Industrial Microbiology/Biotechnology:
Uses microbes in food/drink safety,
pharmaceuticals, and genetic engineering.
Guerrero| BNS2C ‘25 | Module #1​
​
​
●​Early Micropist
●​ Discovery : Coined the term “cell” after
observing thin slices of cork under his
compound microscope.
○​ Note that the tiny compartments looked
like the small rooms (cells) in a monastery.
●​ Function: Initiated the concept of cell
theory—that all living things are made up of
cells. Provided the first recorded microscopic
observations of plant tissue.
●​ Relevance: His work became the foundation
of modern cell biology and microbiology.
Understanding cells as the basic unit of life
is crucial in medicine, genetics, and
biotechnology.
FRANCESCO REDI 1626-1697
●​Experimental Biologist
●​ Discovery
:
Disproved
spontaneous
generation for larger organisms through his
meat and maggot experiment. (redi
Experiment)
​
​
​
​
​
​
1
○​ Showed that maggots only appeared in
meat when flies could lay eggs, not from
the meat itself.
●​ Function: Demonstrated that life arises
from pre-existing life, not from a mystical
“vital force.”
●​ Relevance: Pioneered the scientific method
in biology.
○​ Provided groundwork for the germ theory
of disease, proving organisms do not
appear out of nothing.
REDI’S EXPERIMENT
○​ Developed the process of pasteurization
(heating liquids to kill harmful microbes
without changing flavor).
○​ Created early vaccines for anthrax, rabies,
and chicken cholera.
●​ Function : Showed that microbes were
directly responsible for spoilage and
disease. Laid the foundation for the Germ
Theory of Disease, which revolutionized
medicine and hygiene.
●​ Relevance :
○​ Basis of infection control and public
health measures.
○​ Pasteurization is still used worldwide to
make milk, wine, and other beverages
safe.
○​ His vaccines paved the way for
immunology
and
modern
vaccine
development.
○​ His work continues to influence medicine,
biotechnology, and food science.
●​In 1668, Francesco Redi tested the idea of
spontaneous generation (the belief that life
could arise from nonliving matter). He used
pieces of raw meat in three different
containers:
○​ One left open
○​ One sealed with a cork
○​ One covered with gauze
●​ Goal : to see whether maggots would from
on the meat without flies having having
direct contact
●​ Purpose: To test whether maggots arise
spontaneously
from
rotting
meat
(spontaneous generation), Or if they come
from eggs laid by flies (biogenesis).
●​ What was Redi trying to prove:
○​ He wanted to disprove spontaneous
generation (the old belief that life can
appear from nonliving matter).
○​ He showed that living organisms come
only from other living organisms.
○​ His results proved that maggots do not
come from meat itself, but from fly eggs.
ROBERT KOCH 1843-1910
LOUIS PASTEUR 1822-1895
●​Founder of the Modern Microbiology
●​Discovery : Developed Koch’s Postulates – a
set of criteria to establish a causal
relationship between a microorganism and a
disease. Proved that specific microbes cause
specific diseases. Identified the causative
agents of:
○​ Anthrax (Bacillus anthracis)
○​ Tuberculosis
(Mycobacterium
tuberculosis, 1882)
●​Father of Modern Microbiology | Germ
Theory
●​Discovery: Designed the swan-neck flask
experiment
(1861)
which
disproved
spontaneous generation once and for all,
proving that microorganisms come from
existing microbes in the air.
○​ Demonstrated that fermentation in wine
and beer was caused by microorganisms,
not by chemical reactions alone.
Guerrero| BNS2C ‘25 | Module #1​
​
​
​
​
​
​
​
​
2
○​ Cholera (Vibrio cholerae, 1883)
○​ Introduced pure culture techniques using
agar plates and petri dishes to isolate
bacteria.
●​ Function : Transformed microbiology into a
true experimental science. Provided proof
of
the
Germ
Theory of Disease,
complementing Pasteur’s work.
●​ Relevance : Koch’s Postulates remain a
foundation in infectious disease research.
ALEXANDER FLEMING 1881-1955
●​Antibiotics discoverer
●​Discovery 1982: Discovered penicillin, the
first true antibiotic, when he observed that a
mold (Penicillium notatum) produced a
substance that killed or inhibited many
bacteria growing in a Petri dish.
○​ Marked the beginning of the antibiotic
era.
●​ Function : Provided the first effective
treatment for many bacterial infections
such as pneumonia, syphilis, and strep
throat.
○​ Changed the course of medicine by
allowing infections to be treated rather
than often fatal.
●​ Relevance : Laid the foundation for the
development of modern antibiotics.
JOSEPH LISTER 1827-1912
●​Antiseptic Practices Pioner
●​Discovery: Introduced the use of carbolic
acid
(phenol)
to
sterilize
surgical
instruments, clean wounds, and disinfect
the operating room.
○​ First to apply germ theory to surgery,
showing that microorganisms caused
post-operative infections.
●​ Function : Dramatically reduced surgical
infections and patient mortality.
●​ Relevance : His methods formed the basis of
aseptic technique in modern surgery.
○​ Inspired
the
widespread
use
of
sterilization,
antiseptics,
and
disinfectants in healthcare.
EDWARD JENNER 1749-1823
●​Father of Immunology
●​Discovery : 1796 Developed the first vaccine
by using material from cowpox lesions to
protect against smallpox.
○​ Successfully inoculated a young boy
(James Phipps), demonstrating immunity
to smallpox.
●​ Function : Introduced the principle of
immunization — exposing the body to a
safer form of a pathogen to build protection
against a more dangerous disease.
●​ Relevance : Jenner’s work became the
foundation of vaccination, saving millions
of lives.
○​ Smallpox was completely eradicated in
1980 thanks to vaccination.
○​ Modern vaccines (including COVID-19
vaccines) follow the same immunological
principles he pioneered.
Guerrero| BNS2C ‘25 | Module #1​
​
​
REFERENCES:
●​ Canvas Powerpoint Presentation
​
​
​
​
​
​
3