Exam 2

Question 1

temperature for deep freezing to preserving bacterial cultures

Answer 1

-50° to -95°C

Question 2

lyophilization (freeze-drying)

Answer 2

frozen (-54° to -72°C) and dehydrated in a vacuum

Question 3

developed enrichment culture to study interactions between soil microorganisms

Answer 3

sergei winogradsky

Question 4

aerobic zone –> micro-aerophilic zone –> anaerobic zone –> H2S

Answer 4

top down order of zones of development in the Winogradsky column

Question 5

step 1 of obtaining nitrogen

Answer 5

nitrogen is removed from air and converted to ammonia

Question 6

step 2 of obtaining nitrogen

Answer 6

ammonia is converted to nitrate

Question 7

step 3 of obtaining nitrogen

Answer 7

nitrogen is reduced to form nitrogen gas

Question 8

90% of characterized genera and species of bacteria originate in these four phyla

Answer 8

proteobacteria
actinobacteria
firmicutes
bacteriodetes