In nature...

Question 1

99% of all microbial species have
never been grown as a pure
culture in the laboratory!

Answer 1

99%

Question 2

Factors affecting growth

Answer 2

– Nutrients
– Temperature
– pH
– Osmolarity
– Oxygen
– Pressure
– Radiation (visible light, UV light)

Question 3

Extremophiles:?

Answer 3

microorganisms
that grow preferentially under
extreme conditions.

Question 4

What’s cardinal Temperature ?

Answer 4

the minimum,maximum and optimum growth temperature for a given organisms

Question 5

What happens at the minimum temperature?

Answer 5

• membrane gelling

- membrane process so slow that growth cannot occur

Question 6

What happens in btw the minimum temperature and the optimum temperature?

Answer 6

Enzymatic reactions occuring at increasingly rapid rates

Question 7

What happens at the optimum temperature?

Answer 7

Enzymatic reaction occuring at maximal possible rate

Question 8

What happens at the maximum temperature?

Answer 8

• Protein denaturation
• collapse of the cytoplasmic membrane
• thermal lysis

Question 9

it is possible to distinguish four broad classes of microorganisms in relation to their growth temperature optima

Answer 9

• Psychorophile
• Mesophile
• Thermophile
• Hyperthermophile

Question 10

psychrophiles, T ?

Answer 10

an organism with a growth temperature optimum of 15 C or lower and a maximum growth temperature below 20

Question 11

psychrophiles on pourrait dire ?

Answer 11

low temperature optima

Question 12

Mesophiles, on pourrait dire?

Answer 12

midrange temperature optima

Question 13

Mesophile T?

Answer 13

an organism that grows best at temperatures btw 20 and 40

Question 14

thermophiles, on pourrait dire?

Answer 14

with high temperature optima

Question 15

Thermophiles T?

Answer 15

an organism whose growth temperature optimum lies between 45 and 80

Question 16

Hyperthermophiles, on pourrait dire ?

Answer 16

with very high temperatures optima

Question 17

Hyperthermophiles, T?

Answer 17

species of bacteria or Archaea whose growth temperature optimum is 80 or greater

Question 18

lowest T to the highes T they can grow?

Answer 18

4 to 106

Question 19

Polaromonas vacuolata

Answer 19

4

Question 20

E.coli

Answer 20

39

Question 21

Geobacillys stearothermophilus

Answer 21

60

Question 22

Thermococcus celer

Answer 22

88

Question 23

Pyrolobus fumarii

Answer 23

106

Question 24

Psychrotolerant?

Answer 24

Organisms that can grow at 0°C but have optima around 20 to 40 °C are called

Question 25

What are adaptation to cold temperature?

Answer 25

Changes in protein structure and sequence so the enzyme are active at low temperature

• Transport accros membrane optimally at low T
• modification of the cytoplasmic membrane
• Cold-shock proteins ,help keep active proteins

Question 26

What kills microorganisms at low temperatures?

Answer 26

not the T but the ice crystal

Question 27

At what temperature are microbial cultures preserved in liquid nitrogen

Answer 27

at -80 and -196

Question 28

What important thing microbes need to synthesize to protect themself from the cold?

Answer 28

Cyroprotectants

Question 29

Cryoprotectants?

Answer 29

• antifreeze proteins, glycerol

- help prevent formation of ice crystal that can puncture the cytoplasmic membrane

Question 30

what are barophilic?

Answer 30

grow best at high pressure