Microbiology Ch. 1

Front 1

What are microorganisms?

Back 1

Microscopic (usually) org consisting of single cell or cell cluster; includes viruses & & prions

Front 2

What are the (3) domains of life?

(what isn't included on the tree of life?)

Back 2

1) Bacteria

2) Archaea

3) Eukarya

(Viruses not included b/c don't have rRNA (which translates mRNA-->prots)

Front 3

Elements of microbial structure

Back 3

- Cytoplasmic membrane- seps inside of cell from outside

- Cytoplasm- aqueous mix of macromolecs (prots, lipids, nucleic acids, CHOs), org & inorg molecs, ribosomes

- Cell wall- gives cell strength; relatively permeable (only in plant cells & microorgs, not animals)

Front 4

Properties of ALL cells (3)

(universal)

Back 4

1) Metabolism

- genetic= replication, transcription, translation

- catalytic= energy, biosynth

2) Growth- nutrients from environmt --> new cells

3) Evolution

Front 5

Properties of SOME cells (4)

Back 5

1) Differentiation- cells can form new cell structures (i.e. spore)

2) Communication- chem messengers

3) Genetic exchange

4) Motility

Front 6

LUCA

Back 6

Last Universal Common Ancestor- common ancestral cell that all cells descended from

Front 7

1) Definition of ecosystem

2) Different types of ecosystems

Back 7

1) all living organisms, together w/ they physical & chem components of their environmt

2) aquatic (66% all microorgs in marine subsurface), terrestrial (26% of microorgs), higher orgs

Front 8

Extremophiles

Back 8

- microorgs that live in harsh environments (require it)

- bacteria and archaea

- hyperthermophile- high temps (archaea)

- psychrophile- low temps (bact)

- acidophile- low pH (archaea)

- alkaliphile- high pH (archaea)

- barophile/piezophile- pressure (bacteria)

- halophile- salt (archaea)

Front 9

Fungi

Back 9

- highly diverse

- very abundant in environment (esp soils)

- Lignolytic- wood decaying

- Can be symbiotic w/plant roots (mycorrhizae)

- Can be pathogens

- Can be predators of nematode

Front 10

- Top killers in 1900

- Top killers today

Back 10

- Influenza & pneumonia; TB; gastroenteritis; hrt disease; stroke; kidney disease; accidents

- Hrt disease; cancer; stroke; pulmonary disease; accidents; diabetes

Front 11

Biofuels

Bioremediation

Back 11

- produced by microorgs

- methane (natural gas) produced by methanogens (archaea)

- ethanol produced by microbial fermentation of glue (from corn, grasses or sugarcane)

- Bioremediation- microorgs clean up pollution

Front 12

Robert Hooke's contributions

Back 12

- Developed 1st GOOD microscope

- coined term 'cell'

- 1st to describe microorg

- 1600s

Front 13

Antoni van Leeuwenhoek's contributions

Back 13

- 1st to see bacteria (wee animalcules)

- Made own microscopes- 200X

- Never shared/published method

- 100 yrs before similar magnification achieved

- 1700s

- Found protozoa before bacteria (larger and didn't have technology yet to see bacteria)

Front 14

What were the 2 major questions during the Golden Age of microbiology?

Back 14

Golden Age: 1857-1907

1) How does life originate (does spontaneous generation occur)?

2) What is the nature of infectious disease?

Front 15

Spontaneous generation

Back 15

- idea that microorgs arise out of thin air

- Aristotle 1st proposed (300BC)

- Francesco Redi- rotting meat experiment--> 1 flask unsealed w/meat @ bottom, 1 sealed, 1 covered w/gauze --> proved spont gen wrong

- Renewed debate when Leeuwenhoek discovered microbes in 1674

- Needham experimented w/boiled gravy and plant extracts in vial, sealed w/corks--> cloudy & teeming w/microbes after a few days

- Spallanzani repeated Neeham's work w/mods--> broth stayed clear--> critics unconvinced

- Pasteur- broth poured in flask, heated neck of flask into swan shape, heated broth to sterilize--> no putrification unless flask tipped- put spont gen to rest for good

Front 16

Louis Pasteur's contributions

Back 16

- 1800s

- Disproved spontaneous gen

- Developed pasteurization

- Developed vaccines for anthrax, fowl cholera, rabies

- Father of germ theory & bacteriology (w/Koch)

- Pasteur Institute in Paris- now biomedical research center

Front 17

Early thinkers about disease

1) Lucretius

2) Avicenna

3) Fracastoro

4) Semmelweis

5) Lister

6) Florence Nightingale

Back 17

1) Roman- disease caused by invisible creatures

2) contagion, STDs, quarantine, invisible orgs

3) (1400s) objects foster contagions-->infection

4) (1800s)- before roles of microbes in disease known; women more likely to die from childbed fever (strep) after giving birth in wing of hospital w/med students vs wing w/midwives- req'd student wash hands before entering delivery room--> mortality dropped 10-fold

5) (1800s)- antiseptic techniques--> use of carbolic acid (phenol) in surgery- cut deaths 2/3

6) (1800s)- improved hygiene in mil hospitals during Crimean war (scrubbed rooms, changed dressings elsewhere; est'd 1st nursing school

Front 18

1) Pasteur on disease

2) Koch on disease

Back 18

1) 1800s- hypothesized bacteria responsible for disease

- germ theory of disease

- specific diseases caused by specific pathogens

2)1800s- determined causes of anthrax (originally disease of livestock), cholera, TB

Front 19

Koch's anthrax experiments

Back 19

- Saw bacteria (bacillus anthracis) were always present in bld of infected animal; also saw endospores (resting stages)

- Injected blood of sick mice into healthy mice then injected bld from newly infected mouse into another mouse--> caused disease every time

Front 20

- Development of staining methods

- Value of staining methods

Back 20

- Hans Gram (1800s)- developed stain that separates bacteria into 2 main groups based on their cell walls

- bacillus anthracis= G+ (purple)

- E coli= G- (pink)

- Helps see/distinguish diff microbes under scope based on morphology, size, cell wall chemistry

- still not perfect way to confirm presence of specific org b/c many prokaryotes look same

Front 21

Culture methods

Back 21

- Each bacterial cell deposited on solid medium grows into colony (made of millions of offspring of 1st cell)

- All cells in isolated colony same strain--> can choose colony and isolate into pure culture

- Only .1-1% of bacteria can be grown in culture

Front 22

Koch's TB experiments

Back 22

- Mycobacterium don't stain well due to mycolic acid in cell walls--> acid-fast so hard to stain but once stain retain color in harsh acidic conditions)

- Developed acid-fast staining method

- Used solid media to cultivate bacteria (including anthrax)--> potato slices, gelatin, agar

Front 23

Koch's postulates (4 steps)

Back 23

- Steps to determine causative agent of disease

1) Suspected pathogen must be present in ALL cases of disease & absent from healthy animals

2) Pathogen must be grown in pure culture

3) Cells from pure culture must cause disease in healthy animal

4) Suspect pathogen must be reisolated & shown to be same as original

Front 24

1) Fleming

2) Beijerinck

3) Winogradsky

Back 24

1) Discovered penicillin (1928)- accidental contamination of staphylococcus aureus culture w/penicillium fungus; saved lives in WWII

2) Late 1800s, Dutch- discovered 1st virus (tobacco mosaic virus)

- 1st pure cultures of soil & aquatic orgs

-enrichment culture technique- microorgs isolated from natural samples using special conditions (isolated Azotobacter from soil

3) Late 1800s, Russian

- Biogeochemical cycling

- Chemolithotrophs (oxidation of inorganic compounds for energy);

- Isolated 1st nitrogen fixer (clostridium pasteurianum)

Front 25

What can we do with the discovery of DNA & sequencing methods?

Back 25

- study uncultivable microbes (99%)

- characterize highly diverse microbial communities (like flora in gut)

- study genomes of ind organisms

- study metagenomes of entire microbial communities (all genes in community)