The following are macronutrients, except:

• manganase

• carbon

• oxygen

• nickel

The following are growth factors, except:

• purines

• nitrogen

• amino acids

• vitamins

Lag phase occurs if_______

• cell are damaged

• old cultures used as inoculum

• cells are transferred from rich medium to poor medium

• active cells are inoculated into the same fresh culture medium

Secondary metabolites can be produced by bacteria during _______

• lag phase

• stationary phase

• log phase

• death phase

The following are examples of primary metabolites, except:

• enzymes

• antibiotics

• carbohydrates

• lipids

Choose the correct statement of continuous culture.

• spent medium is continuously removed at the same rate.

• microbial cells are removed with the spent medium.

• fresh nutrient is continuously added.

• culture in an enclosed vessel

What is the function of paddle in the chemostat system?

• to mix the mixture well (nutrient & bacterial cells)

• to control temperature

• to control aeration

• act as cooling agent

Determine crucial factors in controlling the growth rate of a continuous culture:

• fresh nutrient

• dilution rate

• concentration of a limiting nutrient

• flow rate

In which phase, the cell growing at maximum rate?

• lag

• log

• stationary

• death

During the exponential phase, the bacterial growth rate is influenced by various factors such as

• temperature

• concentration of nutrient

• pH

• agitation/aeration

Answer explanation