Bacterial growth and culturing + naming systems

Question 1

What ARE the bacterial growth phases

Answer 1

Lag phase, Log / exponential phase, Stationary phase, Death phase

Question 2

What happens at the lag phase?

Answer 2

Bacteria adapts to new environment
Starts to build up new materials to help in growth
Cell size increases but no new cells

Question 3

What happens at the log / exponential phase?

Answer 3

Exponential cell growth (imagine a y = 2^x curve)
Reproduction and metabolic rate are at its highest

Question 4

What happens at the stationary phase?

Answer 4

Growth starts to slow down as nutrients are depleted and waste products increase
at this point: death rate = growth rate

Question 5

What happens at the death phase?

Answer 5

Cell death is exponential
death rate > growth rate

Question 6

What are some macroelements (macronutrients) needed for bacteria

Answer 6

C, O, H, N, S, P, K, Ca, Mg, Fe
Needed in large quantities
Used to build cell structures and help metabolism

Question 7

What are some micronutrients (trace elements) needed for bacteria

Answer 7

Mn, Zn, Co, Mo, Ni, Cu
Required in small amounts to aid in enzyme function

Question 8

what are the 2 types of media

Answer 8

Defined / synthetic media: all components and conc are known

Complex media: Some ingredients have unknown composition / conc

Question 9

What are the bacterial naming systems based on cell shape

Answer 9

Rod shaped: Bacillus (singular) Bacilli (plural)
Spiral / corkscrew: spirillum (singular)
spirilla (plural)
Spherical: coccus (singular) cocci (plural)
Curved rod: vibrio(s)

Question 10

What is the flow of identification?

Answer 10

From Larger group to Smaller group:
Group / family -> Genus -> Species -> Strain

Strains are a subset of a species with slight differences from other bacteria in the species