What is Microbiology?
Micro - too small to be
seen with the naked eye
Bio - life
ology - study of
Organisms included in the study of
Microbiology
1. Bacteria
Bacteriology
2. Protozoans
Protozoology
3. Algae
Phycology
4. Parasites
Parasitology
5. Yeasts and Molds
• Fungi
Mycology
6. Viruses
Virology
Microorganisms - Microbes - Germs
Bacteriology:
It is science to deal with the study of the bacteria.
Virology:
It is science to deal with the study of the virus.
Mycology:
It is science to deal with the study of fungi.
Immunology:
It is the science to deal with the resistance of the
body to any foreign substance.
Parasitology:
It is the science to deal with Parasites.
The importance of microorganisms:
• Microorganisms are the oldest forms of life.
• Microorganisms have the greatest biomass.
• Microorganisms have killed more people
than have ever been killed in wars.
• Without certain microorganism life could not
exist; produce O2 and N2 .
• Microorganisms are decomposers.
BRANCHES OF STUDY WITHIN
MICROBIOLOGY
• Immunology
• Public health microbiology &
epidemiology
• Food, dairy and aquatic
microbiology
• Biotechnology
• Genetic engineering & recombinant
DNA technology
MICROBES ARE INVOLVED IN
•Nutrient production & energy flow
•Decomposition (bioremediation)
•Production of foods
•Production of drugs & vaccines
•Genetic engineering
• Causing disease
History of the Study of
Microorganisms:
-1665 Robert Hooke
•“little boxes” - “cells”
•Cell Theory - all living things are made up of
cells
•1590 – First compound light microscope
Zacharias Janssen
•Anton van Leeuwenhoek 1674 who was the
first person to actually see living
microorganisms
•Anton Von Leeuwenhoek 1676 –first
observation of bacteria “animalcules
•*As a tailor, used lenses to examine
cloth. It was probably this that led to his
interest in lens making.
•*He assembled nearly 250 microscopes,
some of which magnified objects 270
times.
•*As he looked at things with his
microscopes, he discovered presence of
“micro” organisms - organisms so tiny
that they were invisible to the naked
eye.
•*He called these tiny living organisms
“animalcules”. He first described
bacteria and the protozoans.
• Edward Jenne
vaccine (smallpox)
1796 – First
• 1857 – Germ Theory of Disease
Louis Pasteur
• Rudolph Virchow 1858 the owner
of the Theory of Biogenesis, that said
; Cells can only arise from
preexisting cells
• 1884 Disease transmission Robart
koch Koch’s Postulates who
established the relationship between
Bacillus anthracis and anthrax; also
isolated the bacillus that causes
tuberculosis
• 1885 - Vaccine against Rabies
Louis pasteur
• - Developed vaccines for Chickenpox,
anthrax, rabies
• Demonstrated that all fermentations were due to the
activities of specific yeasts and bacteria.
•
Alexander Fleming
1929
Penicillin (first antibiotic)
Discovery of
• British bacteriologist observed bacterial
staphylococci colonies disappearing on plates
contaminated with mold.
• Fleming extracted the compound from the mold
responsible for destruction of the bacterial colonies.
• The product of the mold was named penicillin,
after the Penicillium mold from which it was
derived
• 1938 – First Electron Microscope
• The electron microscope is capable of magnifying
biological specimens up to one million times.
These computer enhanced images of 1. smallpox,
2. herpes simplex, and 3. mumps are magnified,
respectively, 150,000 and 90,000 times.
• Watson & Crick
Revealed
• Jonas Salk
1953 Structure of DNA
1954 Polio Vaccine
Golden Age of Microbiology 1857 - 1914
Pasteur
•Pasteurization
•Fermentation
Joseph Lister
•Phenol to treat surgical wounds – 1st
attempt to control infections caused by
microoganisms
Robert Koch
•Koch’s Postulates
Edward Jenner
•Vaccination
Paul Erlich
•1st synthetic drug used to treat infections
•Salvarsan - arsenic based chemical to treat
Syphilis
Recent history:
•Genetic engineering
•Cloning
•Human Genome Project
•Biotechnology
•Who knows what is next?
Sizes of Microbes
•Virus -
10 →1000 nanometers *
•Bacteria - 0.1 → 5 micrometers **
(Human eye ) can see .1 mm (1 x 10
-3 m)
* One billionth or 1 x 10 -9 m
** One millionth or 1 x 10 -6 m
Microbes - what comes to mind?
Diseases
Infections
Epidemics
Food Spoilage
Only 1% of all known bacteria cause human
diseases
About 4% of all known bacteria cause plant
diseases
95% of known bacteria are non-pathogens
Microbes Benefit Humans
1. Bacteria are primary decomposers recycle nutrients back into the environment
2. Microbes produce various food products:
•cheese, pickles, green olives
•yogurt, soy sauce, vinegar, bread
Beer, Wine, Alcohol
3. Microbes are used to produce Antibiotics:
• Mold: Penicillin in 1928 by Alexander
Fleming
4. Microbial Antagonism:
•Our normal microbial flora prevents
potential pathogens from gaining access to
our body
Microbes do benefit us, but they are
also capable of causing many
diseases:
Pneumonia, Whooping Cough,
Botulism, Typhoid Fever, Measles
Cholera……………
Tools of Microbiology
1.Compound light Microscope
- live specimens
- 1,000 mag. or less
2. Electron Microscope
- non-living specimens
- > 1,000 X mag.
3. Incubator – keep microbes warm for growth
Techniques of Microbiology
-Staining – to better see structures
-Microbial Culture - growing the tiny beasties
•Container for microbe culture - usually Petri
dish
•Culture media
•Food for the microbes
- E.g. Agar – (from red algae)
- Others such as nutrient broths
Biological OrderedClassification
When classification schemes were first developed,
all living organisms could easily be placed in a
general category, like Kingdom Plantae or Kingdom
Animalia. General categories, such as Kingdoms
still work well in classification but they break down
when some organisms in one category have
characteristics which are similar to organisms in
another category .A case in point is the one-celled
organism, Euglena, which bears both animal and
plant characteristics.
Taxonomic categories •
Depend on this classification; the Living
Organisms is divided in to 3 Domains
(1978 Carl Woese)
•1. Bacteria
•Unicellular prokaryotes with cell wall
containing peptidoglycan
•2. Archaea
•Unicellular prokaryotes with no
peptodoglycan in cell wall
•3. Eukarya
•Protista
•Fungi
•Plantae
•Animalia
Depend on this classification, we can divide
the Living Organisms in to 6 Kingdoms :
1. Animalia
2. Plantae
3. Fungi
4. Protista
5. Arcaebacteria
6. Eubacteria
Type of cells
1.Prokariotic cells: bacteria and bluegreen algae
2.Eukariotic cells: fungi and protozoa
3.Viruses: infective particle that need a
viable cell for their replication and can
be seen using EM
Procaryotes: relative simple morphology
and lack true membrane defined nucleus
Eucaryotes: morphologically complex with a
true membrane enclosed nucleus
viruses
Since viruses are acellular and
possess both living and nonliving
characteristics, they are considered
neither prokaryotic nor eukaryotic.
They will be discussed in separate
section of the course
Domain: Archaea
•Prokaryotic
•Lack peptidoglycan
•Often live in extreme environments
•Not known to cause disease in humans or
animals
•Had been considered bacteria until
examination of their unique rRNA sequences.
-Includes:
–Methanogens
–Extreme halophiles
–Extreme thermophiles
Scope of Microbiology:
•Microbiology has an impact on
medicine, agriculture, food
science, ecology, genetics,
biochemistry, immunology, and
many other fields.
Many microbiologists are primarily interested
in the biology of microorganisms, while others
focus on specific groups;
Virologists - viruses
Bacteriologist - bacteria
Phycologist – algae
Mycologist -fungi
Protozoologist – protozoa
Medical Microbiology:
deals with diseases of humans and animals;
identify and plan measures to eliminate
agents causing infectious diseases.
Agricultural Microbiology:
impact of microorganisms on agriculture;
combat plant diseases that attack important
food crops.
Food and Dairy Microbiology:
prevent microbial spoilage of food
& transmission of food-borne
diseases (e.g. salmonellosis); use
microorganisms to make food such
as cheeses, yogurts, pickles, beer,
etc.
Industrial Microbiology:
using microorganisms to make
products such as antibiotics,
vaccines, steroids, alcohols &
other solvents, vitamins, amino
acids, enzymes, etc.
Genetic Engineering:
Engineered microorganisms
used to make hormones,
antibiotics, vaccines and
other products.