Unit 1The Development of Microbiology

Do Now• What was the last illness you had?

• How sick did you feel?

• Do you know if it was caused by a microorganism? Which one?

The Beginnings• _________ _________ 1665:

• Introduced the world to small objects and creatures when he published his journal – _______________

• It contained illustrations of• Eye of a fly• Stinger of a bee• Shell of a protozoan• Plant-like mold• Cork cells

The Beginnings• _______ _________:

•Spectacle maker from the Netherlands

• Invented the microscope

The Beginnings• _______ ____ ____________ 1670’s

• Seller of silk, wool, and cotton in the Netherlands

• Enhanced Jansenn’s __________ for use in his business

• But his fascination with the microscope led him to examine hair fibers, blood cells and even his own feces

The Beginnings• Anton van Leeuwenhoek (continued)

• Looked at marshy lake water which teemed with microorganisms – he called them ____________

• He contacted the Royal Society of London and sent them letters and drawings of his studies

• But, he was very suspicious and didn’t let any one know how to make his lenses

• He also never made the connection between ______________ and __________

The Transition Period• Biology of the 1700’s consisted of observations of plant

and animal life and attempts to classify them (Linnaeus)

• Scientists did not think of _____________ in terms of tiny living organisms

• Believed that an infectious disease spread by a ________ - an altered chemical quality of the atmosphere which arose from diseased bodies - miasmas

• This miasma theory was believed well into the 1800’s and gradually dissipated with the realization that microorganisms caused ___________ ___________

Do Now• 1. Who invented the microscope?

• 2. Who improved or enhanced the microscope?

• 3. What is the name of the chemical quality of the atmosphere that 1700’s scientists believed caused infectious disease?

Spontaneous Generation

• In the 1700’s many scientists believed that life comes from ____________ __________

• Living conditions - Why does meat get maggots?

• They come from the meat!• ___________ ________ did not agree with

this

Spontaneous Generation

• REDI’S EXPERIMENT 1668

John Needham 1748• ____________ agreed with spontaneous

generation• He boiled bottles of broth (gravy) and said

_________ would kill any organisms already in it• He then _______ the bottles of broth – no air

could enter• After several days, the bottles were

_____________ with microorganisms• He concluded that they arose from the broth

and ______________ ________________ does occur

LAZZARO SPALLAZANI b. 1729

• He knew about Redi and Needham’s experiments and he thought Needham was wrong

• So, Spallanzani did not believe in ____________ ________________

• What mistake do you think he thought Needham had made in his experiment?

LAZZARO SPALLAZANI b. 1729

• He thought Needham hadn’t _________ the broth enough

• He decided to run his own version of the experiment

• He thoroughly boiled the broth and stored some in an _______ container and some in a _______ container

• After several days he saw……• ____ _________________ in the sealed bottle, and

tons in the unsealed bottle

Spallanzani’s Experiment

LAZZARO SPALLAZANI b. 1729

• ________________ do not come from broth – non-life

• They come from ______ ______!• If this were not so then both jars would

have organisms• But many still believed in Spontaneous

Generation – they said that it required ________ and Spallanzani had blocked it out

Disease Transmission• People still believed the Miasma Theory of

infection because then people were not at fault for spreading disease

• In 1847 _________ _____________, a Hungarian doctor, reported that the agent of blood poisoning was transmitted to maternity patients by doctors that had just performed ___________

• He said that hand washing in ________ ________ would stop the spread of disease

• No one listened!!!!!

Disease Transmission• _______ _______, a British doctor traced the

source of an 1854 _______ __________ to London’s municipal water supply

• He said that if people avoided the _______, they would avoid the __________

• People listened and the spread of the disease was stopped

• These 2 doctors showed that disease was caused by an unseen object in the environment – not a miasma.

Do Now• 1. Briefly describe Francesco Redi’s

experiment. What was he trying to disprove?

• 2. Did John Needham agree with Redi?

• 3. Briefly describe Lazzaro Spallanzani’s experiment. What was his conclusion?

The Golden Age• The science of ____________ blossomed

for about 60 years, beginning in 1857• It began with a scientist named

________ _________ and ended about the time of WWI

• Numerous branches of microbiology were established and the foundations for modern microbiology were laid down

Louis Pasteur’s World• In the 1800’s, the world was ravaged by

plague, ___________, typhoid fever, and _______________

• It was necessary to have a _______ ________ to ensure the next generation

• Even royalty could not avoid disease• No one was sure what caused disease –

no cures

Louis Pasteur - Fermentation

• Believed that scientific discoveries should have _____________ applications

• He wanted to find out why local ________ were turning _________

• At the time people thought that wine fermentation resulted from the __________ ______________ of grape juice into wine.

• They didn’t know any living creatures were involved

Louis Pasteur – Fermentation

• But Pasteur’s microscope revealed large numbers of tiny _______ cells

• He correctly believed that the yeasts played a major role in _____________

• In an experiment he removed all yeast from grape juice and it did ______ __________

• Then he added the yeast back and it did ___________ into wine

• He suggested that grape juice be heated to destroy all life before fermentation was begun - _______________

•

Louis Pasteur - Bacteria

• Pasteur also noticed that the sour wines contained tiny sticks and rods known as _____________

• He did an experiment where he removed all ___________ from grape juice

• The when he mixed it with yeast it could ferment and _______ turn sour

Louis Pasteur – Germ Theory

• Pasteur’s discoveries shook the scientific community

• He demonstrated that ________ cells and ___________ were tiny living factories where important chemical changes were occurring

• He also showed _____________ could be agents of change – they could cause a disease rather than being an effect of the disease

• ________ ________ ____ _______– microorganisms are responsible for infectious diseases

LOUIS PASTEUR •People still believed in spontaneous generation!

•Pasteur decided to end the debate once and for all with an ____________ ____________

LOUIS PASTEUR

Pasteur’s Conclusion• He said that life comes from

__________!• This is called _______________• Pasteur’s work brought to an end the

debate of spontaneous generation• Now scientists had to concentrate on

______________ certain microorganisms to specific diseases

Do Now• 1. What did Pasteur conclude was causing the

fermentation of grapes into wine?

• 2. What did he show was causing the wine to turn sour?

• 3. What is the germ theory of disease?

• 4. What did Pasteur’s swan neck experiments disprove?

Robert Koch• Koch was a country doctor from East Prussia

(now Germany) who was concerned with ___________ which infected cattle and sheep

• In a lab in his home, he injected mice with the _________ of diseased cattle, then performed autopsies on the dead mice

• Next he isolated a few __________ from a mouse’s blood and placed it in the sterile aqueous humor from an ox’s ________

Robert Koch• He watched as the bacteria multiplied

and then turned into resistant __________• Next he took several of the spores and

injected them into __________ mice• The symptoms of __________ appeared

within hours• Koch autopsied the mice and found their

blood swarming with ____________

Robert Koch

Robert Koch’s Postulates

Solid Culture Media• Koch developed a solid culture ________

on which bacteria would grow by solidifying beef broth and gelatin

• When inoculated onto the surface, bacteria grew vigorously and produced discrete visible, _____________

• Now _________ is used instead of gelatin because it can resist digestion by certain bacteria and it remains solid when incubated at high temperatures

End of the Golden Age

• The Golden Age witnessed a series of discoveries unparalleled in the identification of the agents of ____________

• Scientists developed an awareness that infectious disease was caused by _______________ and that the chains of transmission could be broken

• These discoveries led to calls for ____________ practices in hospitals, ________________ of milk, _______________ of water, ___________ of insects and __________ in the preparation of foods

• This led to a substantial __________ in the incidence of bacterial diseases – but _________ were still to come!

Compound Light Microscope

Light Path

Light Path

Oil Immersion

Wheat Rust• A disease of wheat caused by a ___________ of

the genus Puccinia• Infections can lead up to ______% yield loss -

exacerbated by dying leaves which fertilize the fungus

• Small brown __________ develop on the leaf blades in a random scatter distribution. They may group into patches in serious cases. Infectious ___________ are transmitted via the soil.