Bioprocess Engineering Questions and Answers Part-1

1. Which components of cell help in the manufacturing of new biological products?
a) Carbohydrates
b) Proteins
c) Lipids
d) Nucleic acids

Answer: b
Explanation: Proteins such as enzymes play a very important role in the manufacturing of biological products, they provide the quality and stability with increased product efficiency and reducing consumption in energy, water and raw materials – and generating less waste.

2. Which of the following activity is not considered in Protein Fractionation which is routinely used in proteomic research?
a) Reduce the size of the protein pool to be analyzed
b) Remove highly expressed proteins
c) Bring Low abundant proteins into dynamic range
d) Bring High abundant proteins into dynamic range

Answer: d
Explanation: The low abundant proteins are preferred over high abundant proteins as the low abundant proteins prove to be informative biomarkers and enrichment of low abundant proteins has the great advantage of obtaining much larger amount of material that can be used for further fractionations and analyses.

3. The genetic information of the Plasmid is essential to survival of the host cells.
a) True
b) False

Answer: b
Explanation: Plasmid is an extra chromosomal circular DNA molecules which are not part of the bacterial genome but carry functions advantageous to the host such as produce enzymes which degrade antibiotics or heavy metals and they are used in recombinant DNA as they can replicate independently of the host chromosome.

4. Which chemical is usually used before the Bacterial transformation process?
a) Calcium chloride
b) Potassium chloride
c) Ferric chloride
d) Sodium chloride

Answer: a
Explanation: Before Bacterial transformation, bacteria are treated with a chemical called Calcium chloride, which causes water to enter into the cells and makes them swell. These swollen bacteria are then known as competent bacteria, which is further used in Bacterial transformation process.

5. Why the shake flask is not continuously preferred?
a) Because of resistant to growth
b) Because of increase rate of contamination
c) Because of imprecise control of temperature
d) Because of unlimited stirring

Answer: c
Explanation: Shake flasks are usually subject to media evaporative loss in warmer culture environments, typically 10% of volume per 24 hr at 37°C. This loss changes the density of the culture and prohibits longer term operation of the system and also the temperature control is absent or limited.

6. Which process is also called product recovery?
a) Upstream processing
b) Mid-stream processing
c) Downstream processing
d) Biological processing

Answer: c
Explanation: Downstream processing implies manufacture of a purified product fit for a specific use, generally in marketable quantities, it also refers to the recovery and purification of biosynthetic products, particularly pharmaceuticals, from natural sources such as animal or plant tissue or fermentation broth, including the recycling of salvageable components and the proper treatment and disposal of waste.

7. The scale-up process is preferred to which condition?
a) The migration of a process from the lab-scale to the pilot plant-scale
b) The migration of a process from the bench-scale to the lab-scale
c) The migration of a process from the small-scale to the lab-scale
d) The migration of a process from the bench-scale to the small-scale

Answer: a
Explanation: In scale-up process, product and process development tend to move forward in small steps, this reduces the risk with larger investments in the next step and production level improvement.

8. Which type of fermentation is preferred in bench top fermenter?
a) Batch
b) Fed-batch
c) Continuous
d) Dual or multiple-fermentation

Answer: b
Explanation: Fed-batch fermentation is superior to conventional batch fermentation when controlling concentrations of a nutrient (or nutrients) affect the yield or productivity of the desired metabolite. The advantage of the fed-batch fermentation is that one can control concentration of fed-substrate in the culture liquid at arbitrarily desired levels.

9. The bench-top bioreactor comes under which type of bioreactor?
a) Solid-state bioreactor
b) Photo bioreactors
c) Airlift bioreactors
d) Stirred tank bioreactors

Answer: d
Explanation: The bench-top bioreactor is a mechanically stirred tank bioreactor fitted with a sparger and a rushton turbine. And its volume varies from < 1-L to 10,000-L capacity. The air is added to the culture medium under pressure through a device called sparger. The sparger may be a ring with many holes or a tube with a single orifice. The sparger along with impellers (agitators) enables better gas distribution system throughout the vessel.

10. From the following volumes, which capacity the Pilot-scale bioreactor holds?
a) 100-1000L
b) 1000-10000L
c) 1-100L
d) less than 1L

Answer: a
Explanation: The Pilot-scale bioreactor vessel of capacity 100-1000L is built according to specifications determined from the bench-scale prototype.