MCQ Bank
Why is excessive foam formation in a bioreactor problematic?
- A) It can lead to blocked air exit filters and pressure build-up
- B) It reduces the cost of operation
- C) It enhances oxygen transfer rates
- D) It speeds up the fermentation process
How does the use of mechanical foam control devices impact the requirement of antifoam agents?
- A) It reduces the requirement
- B) It increases the requirement
- C) It has no impact
- D) It changes the type of antifoam agent required
According to the equation -dN/dt = kN, what does 'N' represent in the context of the destruction of microorganisms during steam sterilization?
- A) d) Reaction rate constant (k)
- B) b) Volume of the batch
- C) a) Time of sterilization treatment
- D) c) Number of viable organisms present
What does VVM stand for in fermenter design?
- A) Volume per Volume per Minute
- B) Variable Volume Meter
- C) Volume Velocity Meter
- D) Volumetric Velocity Measure
If a fermenter has a liquid volume of 2000 liters and the air flow rate is 4000 liters per minute, what is the VVM?
- A) 1 VVM
- B) 4 VVM
- C) 2 VVM
- D) 0.5 VVM
What is used to control foam in a sparged bioreactor?
- A) Antifoaming agents
- B) Antibiotics
- C) Alkaline solutions
- D) Acidic solutions
Considering the balance between foam control and oxygen transfer, what is important when adding antifoaming agents?
- A) Using only silicone-based antifoaming agents
- B) Using the highest possible concentration
- C) Choosing the cheapest available option
- D) Balancing the quantity to avoid excessive addition
Considering the oxygen needs of a specific fermentation process, how critical is the role of VVM in fermenter design?
- A) It is moderately important
- B) It is very important
- C) It is only important for large-scale fermenters
- D) It is not important
What is the significance of using the same basal unit for air flow rate and liquid volume in the VVM calculation? a) b) c) d)
- A) To increase the efficiency of the fermenter
- B) To ensure accuracy in measurement
- C) To simplify the design of the fermenter
- D) To reduce the cost of fermentation
What is the correct definition of sterilization in microbiology?
- A) Slowing down the reproduction of microorganisms
- B) Reducing the microbial load to an acceptable level
- C) Eliminating all forms of microbial life
- D) Inhibiting the growth of bacteria
What are the potential risks associated with pressure build-up in a bioreactor due to foam formation?
- A) Loss of medium and possible damage to the reactor
- B) Reduction in antifoaming agents' requirement
- C) Increased efficiency of fermentation
- D) Easier cleaning and maintenance of the reactor
If the impeller speed in a bioreactor is too slow, what is the likely consequence regarding the bubbles?
- A) The bubbles will rise directly to the surface and may cause a flooded impeller
- B) The bubbles will increase oxygen transfer efficiency
- C) The bubbles will break down effectively
- D) The bubbles will dissolve completely in the liquid
Why do protein-rich media tend to form more foam in bioreactors?
- A) They increase the oxygen transfer rate
- B) They have a higher viscosity
- C) They contain substances that promote foam formation
- D) They decrease the efficacy of antifoaming agents
In a hospital setting, a surgical team needs to sterilize surgical instruments quickly before an emergency procedure. Which sterilization method would be the most time-efficient and effective in this situation?
- A) b) Ethylene oxide gas
- B) c) Autoclaving
- C) a) Gamma radiation
- D) d) Chemical disinfection
If excessive antifoam is added to a bioreactor, what is the likely consequence?
- A) Improved product quality
- B) Increased foam formation
- C) Lower operational costs
- D) Poor oxygen transfer rates
What is the primary method universally used for the sterilization of fermentation media?
- A) c) Ultrasonic treatment
- B) d) Autoclaving
- C) b) Radiation
- D) a) Filtration
What is the most common type of air sparger used in modern bioreactors?
- A) Sparge ring
- B) Ring sparger
- C) Nozzle sparger
- D) Porous sparger