Microbial Ecology

Question 1

Who’s work/studies showed the importance of assessing culture in pure communities?

Answer 1

Robert Koch.

Question 2

How many known microbes can be cultured using known methods?

Answer 2

0.17%.

Question 3

What do microbial ecologists study?

Answer 3

Microbial ecologists study microbes in their natural habitat.

Question 4

What did microbial ecology discover?

Answer 4

Microbial ecology discovered that the biogeochemical cycling of nutrients on Earth is a largely microbial process.

Question 5

Sergei WInogradsky (1856-1953)

Answer 5

1st to study microbes in their natural habitat.

Discovered lithographs, developed enrichment cultures, and built the Winogradsky Column.

Question 6

What is the Winogradsky Column?

Answer 6

Winogradsky Column - a wetland model ecosystem that reflected the relationships and role of bacteria in geochemical cycling.

Question 7

What are endosymbioants?

Answer 7

Endosymbioants - organisms that live symbiotically (close + long-term) inside other organisms.

EX: nitrogen-fixing bacteria + root nodules of plants

Question 8

Lynn Margulis (1938-2011)

Answer 8

Proposed that eukaryotic organelles (mitochondria + chloroplasts) evolved from endosymbiosis.

Question 9

Carl Woese (1928-2012)

Answer 9

Studied recently-discovered prokaryotes from hot springs in 1974 and after analysis of 16s rRNA found that they were a distinct form of life - archaea.

Question 10

What are the 3 domains of life following Carl Woese (1928-2012)’s discovery?

Answer 10

1. Bacteria
2. Eukarya
3. Archaea

Question 11

Do prokaryotes mostly exists as free-living organisms or endosymbionts?

Answer 11

Free-living organisms.

Question 12

What are the stresses prokaryotic organisms are subjected to?

Answer 12

1. Predation
2. Nutrient limitation
3. Osmotic stress
4. Temperature/pH fluctuations