Bacterial guilds, metabolism + tests

Question 1

70S when referring to ribosome indicates…

Answer 1

its buoyancy

Question 2

Obligate aerobe

Answer 2

high O2

Question 3

Anaerobe

Answer 3

low O2

Question 4

Facultative aerobe

Answer 4

lives in presence of O2 but does not require it

Question 5

Microaerophile

Answer 5

not at O2 interface but just below

Question 6

Aerotolerant

Answer 6

prefers anaerobic but can swap

Question 7

Endospores

Answer 7

~ survival form produced under unfavourable conditions

~ highly resistant to heat, drying, radiation + chemicals

Question 8

Name the four types of bacterial cell motility.

Answer 8

~ swimming
~ swarming
~ twitching
~ gliding

Question 9

Name three cell motility tests.

Answer 9

~ motility agar
~ hanging drop
~ Proteus swarming

Question 10

Catalase activity test

Answer 10

catalyses H2O2 –> H2O + 1/2O2
~ +ve result = bubbles seen
~ important reaction in aerobic metabolism

Question 11

Oxidase activity test

Answer 11

detects presence of cytochrome c and associated oxidase
~ add Kovác’s reagent
~ colourless = reduced
~ purple/blue = oxidised

Question 12

Lactose test

Answer 12

~ testing if the bacteria grow on lactose
~ red (no growth) –> yellow (growth) + gas
~ indicator = phenol red

Question 13

H2S production test

Answer 13

~ not produced = orange

~ produced = dark

Question 14

Media kits

Answer 14

~ rapid identification of clinical isolates
~ contain long card with lots of different tests on it
~ substrates are freeze-dried

Question 15

What are the ways of acquiring carbon?

Answer 15

Autotroph –> fixation of inorganic carbon

Heterotroph –> assimilation of organic carbon

Question 16

Nitrogen acquisition

Answer 16

Assimilation

Nitrogen fixation

Question 17

Phosphate acquisition

Answer 17

assimilation

Question 18

Different ways of obtaining energy

Answer 18

phototroph –> light

chemotroph –> chemical reactions

Question 19

Different ways of obtaining electrons

Answer 19

lithotroph –> inorganic compounds

organotroph –> organic matter

Question 20

Guild

Answer 20

group of species that exploit the same class of environmental resources in a similar way regardless of taxonomic position