BI 352: 1/introduction & history of microbiology

What are microbes?

living organisms too small to be seen without a microsope

How are microbes used in food production?

used to make fermented foods

ex- beer, bread, cheese, wine

What are microbes?

living organisms too small to be seen without a microsope

How are microbes used in food production?

used to make fermented foods

ex- beer, bread, cheese, wine

Who was the first person to use and observe microbes with a microscope?

Antonie van Leeuwenhoek

Pasteurization

Louis Pasteur, killing microorganisms by heating milk

What was the green stain first seen?

Pseudomonas aeruginosa, pulmonary infection

What are the 3 types of microbes?

Prokaryotes, viruses, eukaryotes

What are the 3 domains of life?

Eukarya, Bacteria, Archaea

What are the features of prokaryotes?

Unicellular, no nucleus, some have cell walls

ex- bacteria, archaea

What are the features of viruses?

have no domain, acellular, not alive

What are the features of eukaryotes?

unicellular or multicellular, have a nucleus, membrane bound organelles

Which eukaryotes are microbes?

Fungi, algae, protozoa, helminths

What do we exclude from the 3 domains of life?

viruses & prions

What is the theory of spontaneous generation?

life arises from non living matter

What were some thoughts that spontaneous generation helped make?

fleas came from dust, maggots came from rotting meat, frogs came from floods, mice came from grain

Which experiments helped refute spontaneous generation, and which definitely did?

• Redi (open to show flies and maggots, closed for none, halfway/mesh to disprove)

• Spallanzi (open flask was cloudy, closed was clear, microbes come from air)

• Pasteur (particles trapped, cut 1 & saw things grow in broth to show air had something in it)

What was the key difference between Needham & Spallanzi’s experiments?

flask in Spallanzi’s wasn’t fully sealed, Needham didn’t have a control group, different boiling times

Which experiment supported spontaneous generation & why?

Needham’s, broth was heated, cooled and sat to see cloudiness emerge = spontaneous microbes

Who was the first to see microbes & what did he call them?

Leewenhock, animalcules

What is cell theory?

living things are made of cells

Hooke

coined the term cell, saw dead ones in cork

Schleiden

observed cells in plant tissue

Schwann

observed cells in animal tissue

Virchow & Remark

found that cells divided to make new ones

Fleming

discovered mitosis

Hippocrates

disease has a natural cause

Thucydides

evidence based analysis, cause & effect, immunity since plague survivors wouldn’t get sick

Terentius

first to propose that things we can’t see cause disease

Semmelweiss

saw spread of disease between patients, started handwashing between patients

Koch

postulates to determine cause/microbe of disease

Lister

post surgical infections solved by pre-op handwashing with 5% phenol solution, cleaning surgical site & equipment

Snow

worked in London during cholera outbreak, linked to water since beer drinkers were fine

What is endosymbiotic theory?

all cells started as prokaryotes

What steps got us from prokaryotes to eukaryotes?

• membranes folded → membrane-bound organelles

• cell took up aerobic bacteria → mitochondria

• consume photosynthetic bacteria → chloroplast

How does nomenclature work in microbiology?

Genus species

• Genus spp → multiple species

• Genus sp. → unknown/not necessary, general about genus