Why do You
Think
Microorganisms
Should Be
Studied?
https://data.who.int/dashboards/covid19/cases
Why Study
MicrobiologyUnderstand, Prevent,
and Develop a cure.
• Covid-19 is now the deadliest
disease in American history.
• In the US alone there are over 103 M
confirmed cases; 1.2 M deaths
• Life expectancy decreased in 2020
and Covid-19 became the 3rd leading
cause of death.
• The 1918/1919 Flu pandemic killed
an estimated 675,000 Americans.
Data and images from the World Health
Organization
Knowledge leads to Prevention and Treatment
• Record time for
development and
implementation of
a vaccine.
• First mRNA vaccine
approved by the
FDA
Listeria
monocytogenes
The USDA estimates that foodborne illnesses cost the
US approximately 15.5 billion annually
Primary and Secondary Syphilis — Rates of Reported Cases Among Women
Aged 15–44 Years by Jurisdiction, United States and Territories, 2013 and 2022
* Per 100,000
Environmental
Microbiology
• Role of microorganisms in
transforming elemental
species.
• Products of transformation
can be both beneficial and
detrimental
Microbes- Ancient
Inhabitants of Our Planet
• Microbes are responsible for
transforming our planet over time
• We owe our existence to oxygenic
photosynthesizers such as
cyanobacteria.
Food and Drink
Production
Antibiotic
Production
Approximately 75% of
antibiotics are derived from
natural products.
We Are More Microbial Than Human
• The bacteria present in the average
human gut weigh about 2.2 lbs.
• The number of bacterial genes in
your gut is 150 x greater than the
number of genes in your own
genome.
• Even your own genome contains a
number of viral genes.
• Studies suggest that our gut
microbial community influences are
health in a multitude of ways
Microbes are everywhere…
• Viral infections occur at a rate of 1 x 1023 infections per second in the
ocean.
• These infections are responsible for eliminating approximately 30% of
ocean bacteria daily.
• One teaspoon of soil contains 1x109 bacteria that is 1,000,000,000
bacteria.
• Less than 1% of known microbial species are actually pathoge
• Worldwide approximately 16 million people die annually from
infectious disease.
• Prochlorococcus is responsible for benerating approximately 20% of
the oxygen in our biosphere
Chapter 1
Microbial Life Origin and
Discovery
What is a Microorganism?
Microscopic
This Photo by Unknown author is licensed under CC
BY-NC.
Diverse
Is there a microorganism that can be seen by
the unaided eye?
Is there a microorganism that can be seen by
the unaided eye? YES
Thiomargarita magnifica
Do All
Microorganisms
Function
Independently?
Do All Microorganisms
Function Independently? NO
Are all microorganisms... cellular?
Are all microorganisms... cellular? NO.
• Viruses are defined as acellular and have
many characteristics that distinguish them
from cellular organisms
• Viruses are not on the “Tree of Life”
Genome Sequencing
Genome sequencing- DNA sequenced from a pure
culture
• All of the genetic information comes from the same
species
Genome Sequencing
Metagenomics- extracting and sequencing DNA
from an environment instead of a pure culture.
https://rdcu.be/dwzRW
Metagenomics
https://yoursay.sa.gov.au/grantie-islandexperience
|
G EO LO G I C T I M E
Ant hrop ocene: Ag e of Man
We live in t he Holocene ep och, b ut
many scient ist s arg ue t hat human
imp act s, like climat e chang e and
increased ext inct ion rat es, p lace us
in a new ep och: t he Ant hrop ocene.
This infog rap hic d ep ict s t he hist ory of t he Eart h and t he lif e t hat d evelop ed up on it . The Eart h has b een around for nearly 4.6 b illion years and
much has hap p ened in t hat immense sp an of t ime, from g lob al g laciat ions
t o massive ast eroid imp act s. Scient ist s have learned ab out t he long , com p lex hist ory of t he p lanet b y st ud ying layers of rock in t he Eart h’s crust .
These layers cont ain fossils of p lant s and animals t hat lived on Eart h, only a
t iny fract ion of which st ill exist t od ay. By examining t he comp osit ion of
rocks and t he t yp es of fossils in t hem, scient ist s have creat ed a t imeline of
Eart h’s hist ory. It is b roken up int o sect ions b ased on major event s, like
g lob al climat e chang es and mass e xt inct ions. Use t his infog rap hic t o
exp lore t he evolut ion of Eart h and t he lif e up on it .
Ext inct
M ass Ext inct ion e vent
Holocene
Pleist ocene
Humans
300,000 years ag o: The first “mod ern” human—Homo sap iens—evolves in Africa.
The Invisible Neighbors
CENOZOIC
Pliocene
Miocene
6.5 million years ag o: Hominins—early ancest ors of
humans—evolve from t he ot her p rimat es.
Olig ocene
Eocene
Paleocene
60 million years ag o: The first p rimat es ap p ear.
65.5 m ilio n years ag o
MESOZOIC
Cret aceous
130 million years ag o: The first flowering p lant s evolve.
Jurassic
150 million years ag o: Archaeop t eryx,
“t he first b ird ,” lives in Europ e.
Triassic
250 million years ag o: Dinosaurs evolve and b eg in t o d ominat e Eart h.
Permian
310 million years ag o: The four-leg g ed animals, not includ ing amp hib ians, sp lit int o t wo g roup s—
rep t iles and “mammal-like” rep t iles. Mammals event ually evolve from t he second g roup.
200 million years ag o: The first mammals ap p ear.
252.2 m illio n years ag o
PALEOZOIC
Carb oniferous
Devonian
Camb rian
10,000 BCE- Evidence of stored, fermented foods and
beverages
340 million years ag o: The first amp hib ians d evelop .
397 million years ag o: The first animals wit h f our leg s (t et rap od s) evolve. This is
t he common ancest or of all creat ures wit h t wo or four leg s, includ ing humans.
Silurian
Ord ovician
Long before their existence was confirmed, humans were
impacted by microorganisms.
500 million years ag o: Plant s b eg in t o colonize land .
535 million years ag o: Many d ifferent t yp es of org anisms evolve in a relat ively short p eriod of
t ime (a few million years) called t he Camb rian Exp losion. During t his “ exp losion” t he first t rue
vert eb rat e (animal wit h a b ackb one) ap p ear s.
1500 BCE- Mummies are found to have been infected by
tuberculosis, smallpox and polio.
PROTEROZOIC
541 m illio n years ag o
Neo -p rot erozoic
Meso-p rot erozoic
Paleo -p rot erozoic
2 b illion years ag o: First evid ence of eukaryot ic cells—cells t hat cont ain int ernal
“org ans” (org anelles), includ ing a DNA -cont aining nucleus. Recent d iscoveries
sug g est mult icellular lif e may have also d evelop ed d uring t his t ime.
2.4 b illion years ag o: Eart h’s at mosp here fills wit h o xyg en. A million y ears
lat er Eart h freezes over, creat ing t he first “Snowb all Eart h.”
2.5 b illio n years ag o
ARCHEAN
Neo -archean
1347 CE- The Bubonic Plague results in the death of an
estimated 50 million people
Meso-archean
Paleo -archean
Eo-archean
3.5 b illion years ag o: First evid ence of sing le -celled org anisms.
4 b illio n years ag o
HADEAN
4.6 b illion years ag o: Eart h is formed . The moon f orms ab out 100 million y ears aft erward s.
Microbe
Earth Comes Into
Existence
Evolution of
Prokaryotic Cells
Humans Come Into Existence
Microbes Shape Human History
Florence Nightingale
Notes on Matters Affecting the Health,
Efficiency and Hospital Administration of
the British Army 1858
Robert Hooke
Antonie Van Leewenhoek
Antonie van Leeuwenhoek
“To my great surprise
[I] perceived that the
aforesaid matter
contained very many
small living Animals,
which moved
themselves very
extravagantly”
Video
Spontaneous Generation- How do microbes
come into existence?
• Necessity is truly the mother of invention
• Spallanzani (18th century)- successfully showed
that sterilized broth would not become
contaminated.
• No air
• Louis Pasteur (19th century)- Swan-necked flask
Louis Pasteur- a Jack of all Trades
Fermentation is a biologically driven process
Abiogenesis
The Origins of Life
• Stanley Miller and Harold
Urey
• Successfully created simple
amino acids in a prebiotic mix
• Juan Oro
• By including HCN, adenine was
generated
Medical Microbiology
Scientific Method
• Early 1900’s
• Koch utilized the
scientific method to
demonstrate the
chain of infection
• Initially worked with
Bacillus anthracis but
also determined the
etiology of
tuberculosis
Robert Koch
Varioliation
A letter from Abigail Adams to John Adams (1776)
“…at present all my attention is taken up with
the care of our Little Charles who has been very
bad. The Symptoms rose to a burning fever…
and delirium ensued for 48 hours:
Smallpox has a huge impact on the Revolutionary War and at the time
there was much debate on the risks and benefits of “inoculation”.
Some regions even outlawed the practice.
Vaccinations Have Come A Long Way
Some Commonly Administered
Vaccines
• Rabies
• Measles
• Varicella
• Diptheria
• Tetnus
• Mumps
• Rubella
• Influenza
https://www.primarypedsmd.com/news/pfizer-covid-vaccine-for-1215-year-olds/
Microbial Ecology
Microbial Ecology
• Microbes do not operate in isolation.
• How do they operate in their natural
environment, and does that differ from the
laboratory environment?
• Sergei Winogradsky
• Biogeochemical cycling
• Lithotrophs
Nitrogen
Gas
Nitrate
Ammonia
Microbial
EcologyMicrobiomes