1.2.1 Environmental factors influencing the Growth

Question 1

What are the Environmental factors influencing the growth of bacter?

Answer 1

pH
Temp
Gaseous composition

Question 2

Optimal growth between 10 C to 20 C

Answer 2

Psychrophiles

Question 3

Optimal growth between 20 C to 40 C

Answer 3

Mesophiles

Question 4

Optimal growth between 50 C to 60 C

Answer 4

Thermophiles

Question 5

Example of psychrophiles bacteria?

Answer 5

Moraxella
Flavobacterium
Moritella
Vibrio
Pseudomonas

Question 6

Example of Gram positive psychrophiles?

Answer 6

Arthrobacter
Bacillus
Micrococcus

Question 7

Example of Mesophiles

Answer 7

S. aureus
E. coli
Streptococcus pneumoniae
Strep. pyogenes
Heamophilus influenzae

Question 8

Example of Thermophiles?

Answer 8

Thermus aquaticus
Thermococcus litoralis

Question 9

Use as Biological indicator for autoclave?

Answer 9

Geobacillus stearothermophilus

Question 10

The temperature for routine incubation in microbiological practices?

Answer 10

35°C ± 2

Question 11

Optimal growth at pH <6.5

Answer 11

Acidophiles

Question 12

Optimal growth at pH 6.5 - 7.5

Answer 12

Neutrophiles

Question 13

Optimal growth at pH 7.5>

Answer 13

Alkaliphiles

Question 14

Example of Acidophiles?

Answer 14

Lactobacillus

Question 15

Example of Neutrophiles?

Answer 15

E. coli
Staph
Salmonella

Question 16

Example of Alkaliphiles?

Answer 16

Vibrio cholerae

Question 17

Vibrio cholerae grows best at?

Answer 17

8 but can still grow at 11

Question 18

Requires oxygen for growth?

Answer 18

Obligate aerobes (Seen in top part of the tube)

Question 19

Example of Obligate aerobes?

Answer 19

Nocardia
Citrobacter
Klebsiella
Proteus
Salmonella
Mycobacterium tuberculosis

Question 20

Cannot grow in the presence of oxygen

Answer 20

Obligate anaerobes (Seen in the bottom part of the tube)

Question 21

Example of obligate anaerobes?

Answer 21

Bacteroides fragilis
Lactobacillus
Clostridium
Fusobacterium

Question 22

Can grow either with or without oxygen

Answer 22

Facultative anaerobes (Can be seen in the whole tube but predominantly seen on the top of the tube

Question 23

Example of facultative anaerobe

Answer 23

E. coli
Pseudomonas aeruginosa
Staph
Listeria
Salmonella
Shewanella
Yerisnia

Question 24

Can survive in the presence of Oxygen but do not use oxygen in metabolism

Answer 24

Aerotolerant anaerobes

Question 25

Example of Aerotolerant anaerobes

Answer 25

Streptococcus spp.

Question 26

Requires a reduced level of oxygen to grow

Answer 26

Microaerophiles

Question 27

Example of microaerophiles?

Answer 27

Campylobacter jejuni

Question 28

How many percent of oxygen required for campylobacter jejuni?

Answer 28

5-6%

Question 29

Requires an atmosphere enriched with extra carbon dioxide (5-10%)

Answer 29

Capnophiles

Question 30

Example of Capnophiles?

Answer 30

Neisseria gonorrhoeae