Prokaryotic Biology Lecture 2/Chapter 1

improved continuously

Light microscope invented in 1600s, quality __________

small eukaryotes (eukaryotic cells)(dead cells from plants)

mid-1600s: Robert Hooke observed ____________________

bacteria (prokaryotic cells)

1676: van Leeuwenhoek discovered ____________

Biogenesis

Living organisms arise from preexisting life

spontaneous generation

The alternative hypothesis is __________________—that living organisms can arise from non-living matter

Redi

1688: ______ shows that flies do not spontaneously

generate and therefore disproved spontaneous generation

John Needham

– Even after Redi’s experiments disproved spontaneous

generation for flies, many people thought that microbes

were an exception.

– _______________ (1745)put boiled nutrient broth into a sealed flask

Spallanzani

__________ (1765)—placed nutrient broth in a flask, sealed it and sterilized it by boiling—no microbes grew

– This same scientist argued that this disproved spontaneous generation for microbes

lack of air in the sealed flasks

after spallanzani’s experiment some argued that microbes were there, but had not been able to grow due to _______________. Definitive proof was lacking

spontaneous generation for microbes

– Pasteur performed a brilliant experiment (1861):

• S-shaped flasks kept microbial contaminants out, but let air in

• Pasteur demonstrated that microorganisms are present in the air, and contaminate the broth when the flask is open and they fall in.

This finally disproved ____________________________

• Disapproval of spontaneous generation.

• Microbes cause fermentation.(worked in a wine brewery)

• Early vaccine development.

• Pasteurization

Louis Pasteur(4)

-63 degrees C, 30 min

-72 degrees C, 15 sec(HTST)

-140 degrees C, 1 sec(UHT)

-Kill pathogen and spoilage microbes

Process of Paseuriztion

viruses, bacteria, fungi, or protozoa

Disease-causing organisms, what we usually mean when we

say “germs”, are ______, _______, _______, and __________

Germ

______ is not a useful word in microbiology

Archaea

no _________ have been demonstrated to cause human disease

• Rabies—transmitted to new host when bitten by an infected animal

• Anthrax—in the 1800’s people knew it was possible to

catch this from cattle

• Battlefield infections--significance of infection in warfare

was 1st recognized by the British nurse Florence

Nightingale (1820–1910)

• Wound sepsis—Lister found that sterilization of surgical

instruments reduced wound sepsis, gangrene, death

4 supporting observations of Germ-Theory

sterilization

pasteurization is not the same as ____________

Koch’s Postulates

• Provides means of testing hypothesis:

– “Does this germ cause that disease?”

– Causality?

• Organism must meet 4 criteria:

– 1. Microbe always present in diseased

• Absent in healthy

– 2. Microbe is grown in pure culture

• No contamination of other microbes.

– 3. Introduce pure microbe into healthy individual

• Individual becomes sick (same disease)

– 4. Same microbe re-isolated from now-sick individual

4 of Koch’s Postulates

• Some organisms cannot be grown in pure culture.

• Using humans in completing the postulates is

unethical (no animal model).

• Cofactors are needed for disease development

(ubiquitous pathogens, not every infected one

develops disease).

• Some diseases develop extremely slow.

• Molecular and genetic evidence may replace and

overcome these limits

Limitations of Koch’s Postulates

MEMORIZE THIS CHART(the golden Age of microbioogy)

Handwashing and Antiseptic surgery

2 antiseptic practices but into use in the 19th century to prevent disease and kill germs

Ignaz Semmelweis (1818-65)

discovered handwashing

Joseph Lister (1827-1912)

started Antiseptic surgery

Alexander Fleming

1929-1941: discovered Penicillin

-overtime bacteria became resistant

Variolation

powdered smallpox scabs were blown up the noses of healthy

-used by Turkish physicians, Lady Montagu, Edward

Jenner

– Black death/plague in Europe

– Smallpox in Americas

2 examples of microbial diseases change history

– Diseases destroying crops (Irish famine)

– Control of microbial growth to preserve food

– Fermentation in food/beverage production

• bread, wine, cheese

• Chocolate!

Examples of microbes affect food availability

plants and animals

Microbes lived before ______ and _______

• Anaerobic

– bottom of swamp, in our gut

• High pressure

– Bottom of ocean

• Hot or cold temperatures

– Below 0°C to 113°C

• No organic carbon

– Use light for energy, CO2 for carbon

4 varied conditions that microbes live in

Microbes

______________ are the only living organism for the first 2

billion years

-bacteria fix N2 to NH4

-Nitrify NH3 to NO3-

what happens in the nitrogen cycle

-Photosynthetic microbes fix most carbon

-Many other conversion

what happens in the carbon cycle

nitrogen carbon, sulfur, phosphorus cycle

4 cycles that microbes are involved in on earth

E. Coli

________ has the best understood genome

Botox

________ is a neurotoxin made by bacterium Clostridium botulinum

Botulinum (Latin botulus = "sausage”)

______________________ toxin is one of the most poisonous natural substances in the world

unable to contract for a period of 4 to 6 months

A small dose of Botox decreases muscle activity, so the muscle is _________________________

 Recombinant DNA / Molecular Cloning

 Beginning of Biotech

 Genome editing with CRISPR / Cas9

(clustered regularly interspaced short

palindromic repeats)

 Nobel Prize 2020 was awarded to Emmanuelle Charpentier and Jennifer A. Doudna "for the development of a method for genome editing."

 Optogenetics: controlling the brain with light

5 amazing applications of microbiology

-most popular and diverse group of organisms

-found everywhere on earth

-important for recycling essential elements

-carries nutrients and some do photosynthesis

-helps society as they’re crucial for food and beverage production, medicines, and products needed for manufacturing

-decompose organic waste

-widely used in tools in biomedical research

-some cause disease in plants and animals

-the importance of microorganisms

-make fermented food

-make medicine(insulin, interferon, industrial products(biofuel))

-recycle waste

-biological control(BT as pesticide)

4 ways microbiology has lead humans to increase growth in microbes

-prevent food spoilage

-prevent disease occurrence(public health, personal hygiene, anti microbial drugs, vaccine)

4 ways microbiology has lead humans to decrease growth in microbes

von Behring - Diphtheria antitoxin

Nobel prize

1901

Ross Malaria - transmission

Nobel prize

1902

Koch TB - bacterium

Nobel prize

1905

Metchnikoff Ehrlich- Immunity

1908 Nobel Prize

Fleming, Chain, Florey - Penicillin

1945 Nobel Prize

Waksman - Streptomycin

1952 Nobel Prize

Delbrück, Hershey, Luria Viral - replication

1969 Nobel Prize

Tonegawa - Antibody genetics

1987 Nobel Prize

Prusiner - Prions

1997 Nobel Prize

Marshall, Warren - H pylori

2005 Nobel Prize

Hausen, Barré-Sinoussi, Montagnier - HPV, HIV

2008 Nobel Prize

Beutler, Hoffmann, Steinman - TLR, Dendritic cells

2011 Nobel Prize

Campbell, Omura, Tu, - Therapy for parasite/malaria

2015 Nobel Prize

Ohsumi - Autophagy

2016 Nobel Prize

Dubochet, Frank, Henderson - CryoEM

2017 Nobel Prize

Allison, Honjo - Cancer Immune Therapy

2018 Nobel Prize

Arnold, Smith, Winter- Enzyme artificial evolution/Phage display

2018 Nobel Prize

Charpentier, Doudna -CRISPR for genome editing

2020 Nobel prize

Alter, Houghton, Rice - HCV

2020 Nobel Prize

Drew Weissman, Katalin Karikó - mRNA Vaccine

2023 Nobel Prize

Edward Jenner(England)

Discoverer in 1798 that cowpox vaccinations prevent smallpox

Semmelweis

Discoverer in 1847 that chlorine as antiseptic wash for doctors hands decreases pathogens

Florence Nightingale

discoverer in 1855 that sanitation is correlation with mortality(Crimean war)

Louis Pasteur

discovered in 1864 that microbes fail to appear spontaneously

Joseph Lister

discovered in 1867 that antisepsis during surgery prevents death

Robert Koch

discovered in 1867 that bacteria are the causative agent of Anthrax

Louis Pasteur

discovered in 1881 the first artificial vaccine against anthrax

Peyton Rous

discovered in 1911 that viruses are found to cause cancer in Chickens

Fleming, Florey, Chain

In 1929, discovered penicillin, first widely used antiboitic, made by a fungus

Hans Kreb

In 1937, the tricarboxylic acid cycle is discovered by

Avery, Macleod, Mccarthy

discovers in 1944 that DNA is a genetic material that transforms S. pneumonae

Franklin and Wilkins

discovers in 1953 that the structure of DNA is identified by X-ray diffraction as a double helix

Watson and Crick

discovered in 1953 that DNA consists of antiparallel chains connected by hydrogen bonding of AT and GC base pairs

mitchel and moyle

discovered in 1961 the chemiotactic theory, which states that biochemical energy is the stored in a transmembrane protein, is proposed and tested