Microbial growth

Question 1

microbial growth

Answer 1

increase in cell numbers in population or in microbial mass

Question 2

generation time

Answer 2

time required for cell to divide into 2 or population to double , depends on the growth medium and incubation conditions

Question 3

growth rate

Answer 3

is a change in cell numbers for cell mass per unit time

Question 4

batch culture

Answer 4

can obtain exponential growth, limited amount of nutrients ( lag, log, stationary, decline phases)

Question 5

wha is used to measure turbidity

Answer 5

spectrophotometer

Question 6

membrane gelling

Answer 6

transportation of nutrients is low so growth cannot occur

Question 7

describes 5 types of microbes dependent on their temperatures

Answer 7

mesophiles- body temp
thermophiles- 40-60
hyperthermosphiles- extreme hot 
psychrophiles- -10
psychrotrophs - low temp 0 ( listeria mono)

Question 8

which bacteria can survive freezing

Answer 8

E.cole, campylobacter, emertic spores

Question 9

obligate anaerobe

Answer 9

killed by oxygen

Question 10

facultative anaerobe

Answer 10

can live in both anaerobic and aerobic conditions

Question 11

aerotolerant anaerobe

Answer 11

ignore oxygen, don’t use it in metabolism

Question 12

microaerophilic

Answer 12

does not grow in oxygen under normal atmospheric pressure

Question 13

barotolerant

Answer 13

affected by high pressure

Question 14

barophilic

Answer 14

require high pressure

Question 15

radiation tolerant

Answer 15

carotenoids pigments protect light exposed microorganisms from photooxidation, UV light and visible light

Question 16

osmotolerant organisms

Answer 16

grow over wide range of water activity