Topic 7

Question 1

Fundamental vs Realized Niche

Answer 1

Fundamental: the theoretical range of environments where a given microbe could live

Realized: the range of environments where that microbe actually lives in the real world

Question 2

Symbiosis

Answer 2

close, long-term interaction between different organisms; often involve co-evolution; often physical interaction

Question 3

T or F. Many important interactions are transient and not true symbiosis

Answer 3

T!

Question 4

Lichens are microbial communities comprised of two dominant organisms

Answer 4

1) fungus (eukaryote)

2) an alga (eukaryote) and/or a cyanobacterium

Question 5

Microbial consortium

Answer 5

Two or more microbes living in a symbiotic relationship

Question 6

“Chlorochromatium aggregatum”

Answer 6

• not single species
• green sulphur bacteria (phototrophs)
• beta-proteobacterium (motile)
• consortium always found together but not singular species

Question 7

Cross-feeding

Answer 7

one organism’s waste is another’s food

Question 8

Community-level metabolic processes

Answer 8

metabolic processes that require many distinct organisms to complete

Question 9

Direct combat

Answer 9

antimicrobial mechanisms

- kill other microbes or slow them down to acquire the desired substance

Question 10

Complex interactions

Answer 10

• not true symbiosis
• dynamic
• cross-feeding
  community-level metabolic processes
• direct combat

Question 11

Bacteriocins

Answer 11

• protein toxins produced by bacteria
• similar to antibiotics and T6SS
• strain to strain variation
• immunity proteins protect producers

Question 12

Nisins

Answer 12

• bacteriocins
• used for food preservation
• targets cell wall synthesis and is active against a broad spectrum of gram positive bacteria
• 11 genes required
• enzymes can modify this

Question 13

“Killer Yeasts”

Answer 13

produce toxins that kill other yeasts

Question 14

LCV

Answer 14

Legionella containing vacuoles