Category: Fermentation Technology Objective Questions

Fermentation Technology Multiple Choice Questions on “Other Fermentation Vessels”.

1. The operating volume of Waldhof-type fermenter is __________ for broth and air.
A. 252,000 dm³
B. 225,000 dm³
C. 215,000 dm³
D. 232,000 dm³id5fdb77458223e”

Answer: B
Clarification: The operating value of Waldhof-type fermenter is 225,000 dm³ for an emulsion of both broth and air. It was 100,000 dm³ for broth without air. The non-sterile air was introduced into the fermenter through rotating pin-wheel aerator.

2. What led to the development of Walhof-type fermenter?
A. Yeast growth
B. Bacterial growth
C. Viral growth
D. Fungi growthid5fdb774582260″

Answer: A
Clarification: The growth of yeast in sulphite waste liquor led to the development of Walhof-type fermenter. The investigations were done in Germany, Japan, and the United States of America.

3. The diameter of Waldhof-type fermenter was _______
A. 8.0 m
B. 7.8 m
C. 7.9 m
D. 8.1 mid5fdb77458226e”

Answer: C
Clarification: The diameter of Waldhof-type fermenter was 7.9 m. It was 4.3 m in height with the central tube of 1.2 m in diameter. It was made up of carbon steel, clad in stainless steel.

4. Which manufacturer developed vinegator?
A. Chemap AG
B. Solida Biotech
C. LanzaTech
D. Arzedaid5fdb77458227a”

Answer: A
Clarification: Chemap AG of Switzerland manufactured the Vinegator. Chemap solves the filtration tasks and is suited to filtration applications in which washing, drying, extraction are parts of filtration. These systems are used in Fermentation Technology, Pharmaceuticals, etc.

5. Who defined Tower Fermenter?
A. Cohee
B. Steffen
C. Ebner
D. Greenshieldsid5fdb774582285″

Answer: D
Clarification: Tower Fermenter was defined by Greenshields et al. in 1971. They described it as an elongated non-mechanically stirred fermenter with an aspect ratio of 6:1 for the tubular section or 10:1 overall.

6. The Tower fermenter was first described for _____________
A. Amylase production
B. Citric acid production
C. Cheese production
D. Beer productionid5fdb774582290″

Answer: B
Clarification: Tower fermenter was first described for citric acid production. It was in the form of glass having height: diameter ratio of 16:1 and a volume of about 3 dm³. It was the simplest type of fermenter.

7. The tower beer fermenter was patented by _________
A. Shore
B. Ulenberg
C. Owen
D. Victereroid5fdb77458229a”

Answer: A
Clarification: A vertical-tower beer fermenter was patented by Shore et al. The perforated plates were introduced in the fermenter to maximize the production of yeast.

8. Who proposed the use of cylindro-conical vessels?
A. Nathan
B. Boulton
C. Maule
D. Smithid5fdb7745822a4″

Answer: A
Clarification: The use of cylindro-conical vessels was proposed by Nathan in 1930. It was used in the brewing of lager. The operating height of vessel was 10 to 20 m and the volume of the vessel was 150,000 dm³ to 200,000 dm³.

9. Which of the following is the disadvantage of cylindro-conical vessels in brewing?
A. Time-consuming
B. Fermentation and conditioning can be carried out in the same vessel
C. Reduction in maturing time
D. Yeast separation is goodid5fdb7745822ae”

Answer: A
Clarification: The advantages of cylindro-conical vessels in brewing are: i) Reduced processing time by movement within the vessel. ii) Fermentation and conditioning are carried out in the same vessel. iii) The separation of yeast is easy and good. iv) The maturing time is reduced.

10. Which of the following is not the type of airlift fermenter?
A. Concentric Draft loop
B. Tower loop
C. ICI deep shaft
D. High pressureid5fdb7745822b8″

Answer: D
Clarification: The Airlift/Gaslift fermenters are used to reduce stress by the elimination of mechanical agitators. They are alternative to the mechanical agitated system and are mainly of 4 types: Concentric draft loop, Tower loop, ICI deep shaft, Low-pressure airlift fermenter.

11. Who developed multiple air-lift fermenters?
A. Bakker
B. Hamer
C. Reuss
D. Bayerid5fdb7745822c2″

Answer: A
Clarification: Bakker et al. in 1993 developed a multiple air-lift fermenter system in which three fermenters were incorporated into one vessel. It consists of two compartments: a central compartment and middle compartment.

12. Which of the following scientist developed the cyclone column?
A. Meyrath
B. Dawson
C. Wu
D. Hamerid5fdb7745822cb”

Answer: B
Clarification: Dawson in 1974 developed the cyclone column. It was particularly for the growth of filamentous cultures. Dawson also listed important bacteria, fungal, and yeast applications in the production of the vaccine.

13. ‘Dowpac’ is derivative of _____________
A. Polystyrene
B. Polyethene
C. Polyethylene Glycol
D. Teflonid5fdb7745822d5″

Answer: A
Clarification: The derivative of polystyrene is ‘Dowpac’. In packed towers, the column was packed with ‘Dowpac’. The packed towers are useful in the treatment of sewage and effluent.

14. Rotating-disc fermenters are used in effluent treatment.
A. True
B. Falseid5fdb7745822df”

Answer: A
Clarification: The rotating-disc fermenters are useful in the treatment of effluent. They utilize growing microbial film on rotating discs for oxidizing the effluent. The variety of fungi can be grown on the rotating discs.

15. The fermenter vessel has to pass through several tests before entering the market.
A. True
B. Falseid5fdb7745822e9″

Answer: A
Clarification: The vessel has to pass through several tests before entering the market. Those vessels which pass the tests is given a certificate by the insurance companies which then allow the vessel to be operated in the laboratory or factory.

Fermentation Technology Multiple Choice Questions on “Media Design and Preparation for Bioprocesses – Filtration”.

1. What is the pore size of the filtration membrane to remove bacteria?
A. 0.25 µm
B. 0.22 µm
C. 0.27 µm
D. 0.26 µmid5fdc811bb0f8e”

Answer: B
Clarification: The pore size of the filtration membrane to remove the bacteria is 0.22 µm. Filtration is very useful in removal for unnecessary components of the medium. The sterility of the filtration is also an important aspect.

2. The pore size for the removal of viruses is _______________
A. 20 nm
B. 30 nm
C. 25 nm
D. 35 nmid5fdc811bb0fb1″

Answer: A
Clarification: The pore size of the filtration membrane for the removal of the virus is 20 nm. The viruses are smaller than bacteria and therefore the pore size for the removal of the virus is less than that of bacteria. Viruses also reproduce inside the bacteria and can infect them which are commonly referred to as bacteriophage.

3. Which of the following is not the application of filtration?
A. Sterilization of media
B. Removal of debris
C. Plasma clarification
D. Off-gas analysisid5fdc811bb0fc0″

Answer: D
Clarification: Off-gas analysis is done with the help of mass spectroscopy and not by the filtration process. The applications of filtration are to sterilize the media, removal of debris, plasma clarification, serum clarification, endotoxin removal, cell culture clarification, additive, and buffer sterilization.

4. Which of the following filters are ideal for vitamin sterilization?
A. Bottle top filters
B. Cellulose Nitrate filters
C. Cellulose Acetate filters
D. PES membrane filtersid5fdc811bb0fcb”

Answer: A
Clarification: The bottle top filters are ideal for the sterilization of vitamins, growth factors, trace elements, buffers, etc. It is useful for sterilizing small volumes. It has a range of membranes and pore sizes which are used for suitable purposes.

5. Which of the following filter is used in the filtration of bacteria?
A. Bottle top filters
B. Oxalate filters
C. Cellulose Acetate filters
D. PES membrane filtersid5fdc811bb0fd5″

Answer: C
Clarification: Cellulose Acetate filters are used in the filtration of bacteria with a pore size of 0.22 µm. Cellulose Nitrate filters are also used for the filtration of bacteria and for sterilization of buffers and solutions.

6. The advantage of cellulose acetate filters is ________________
A. Recovery of microorganisms
B. Low throughput
C. High protein binding
D. Low flow ratesid5fdc811bb0fdf”

Answer: A
Clarification: The analytical filters along with cellulose acetate membranes are used for the recovery of microorganisms at the laboratory or industrial scale. The drawbacks of cellulose acetate filters are low throughput, high protein binding, and low flow rates.

7. Which of the following is not an advantage of PES membrane filters?
A. Low extractables
B. Fast flow
C. High protein binding
D. High throughputid5fdc811bb0fe8″

Answer: C
Clarification: The advantages of PES membrane filter have low extractables, fast flow, low protein binding, fast flow, high throughput. They are used for the sterilization of small or large volumes according to laboratory use.

8. In which of the following the size of particles retained is much smaller than the pore size of the medium?
A. Batch filtration
B. Surface filtration
C. Submerged filtration
D. Depth filtrationid5fdc811bb0ff2″

Answer: D
Clarification: In depth filtration, the size of particles retained is much smaller than the pore size of the medium. It has high capacity and the strength of filter is also higher. Examples are ceramic and sintered filters.

9. Which of the following does not influence filtration?
A. Temperature
B. Density
C. Viscosity
D. pHid5fdc811bb0ffc”

Answer: D
Clarification: The pH of the solution does not influence the filtration of the solution. The factors that affect the filtration are temperature, density, pressure, viscosity, particle size, particle shape, charge, and corrosiveness.

10. Filtration is a steady state.
A. True
B. Falseid5fdc811bb1005″

Answer: B
Clarification: The flow of liquid through a filter follows the basic rules that govern the flow of any liquid through medium offering resistance. Rate of flow is the ratio of driving force to resistance. The resistance is not constant, it increases with an increase in deposition of solids on the filter medium. Therefore, filtration is not a steady state.

11. In surface filtration, the size of particles retained is higher than the mean pore size of the medium.
A. True
B. Falseid5fdc811bb100e”

Answer: A
Clarification: The size of particles is higher than the mean pore size of the medium. It has low capacity and the particles size retained is more predictable. Examples are cellulose Acetate and Cellulose Nitrate filters.

12. The slurry is ______________
A. A suspension to be filtered
B. A porous membrane used to retain the solids
C. The solids which are present on the filter
D. A clear liquid passing through the filterid5fdc811bb1017″

Answer: A
Clarification: The slurry is a suspension that is to be filtered. It is a semi-liquid mixture which consists typically of fine particles of cement, manure, or coal suspended in water.

13. What do you mean by filter cake?
A. The cake which is to be filtered
B. A porous membrane used to retain the solids
C. The solids which are present on the filter
D. A suspension to be filteredid5fdc811bb102e”

Answer: C
Clarification: The filter cake consists of the solids which are present on the filter. It is usually the insoluble matter which is left on the filter. As the cake grows, the particulate matter is retained, resulting in the thickening of cake.

14. Which of the following process is used to separate insoluble particles from liquids?
A. Filtration
B. Extraction
C. Drying
D. Sievingid5fdc811bb1037″

Answer: A
Clarification: The filtration is the process of separation of insoluble particles from liquids. It can be physical, mechanical, biological methods are used for separation of solids from fluids. The filtrate is obtained which is collected in a glass and the residue remains on the filter.

Fermentation Technology Multiple Choice Questions on “Large Capacity Fermenters”.

1. The capacity of cylindrical fermenters is __________
A. 400 – 1000 hl
B. 500 – 1000 hl
C. 1000 – 2000 hl
D. 500 – 2000 hlid5fdb3a9d08477″

Answer: D
Clarification: The capacity of the cylindrical fermenters is 500 – 1000 hl. The cylindrical vessel is oriented in a horizontal and vertical plane and is of a closed design and has good hygienic properties and carbon dioxide collection is possible.

2. Who developed the cylindroconical fermenters?
A. Nathan
B. Witt
C. Hewlett
D. Monodid5fdb3a9d08499″

Answer: A
Clarification: Nathan developed and designed the style of cylindroconical fermenters in 1930 at the end of the nineteenth and initially introduced in Switzerland. It was used to improve the efficiency of the traditional lager fermentation.

3. The original Nathan vessels were constructed from ___________
A. Glass
B. Iron
C. Steel
D. Aluminiumid5fdb3a9d084a8″

Answer: D
Clarification: The original Nathan vessels were constructed from Aluminium. This was a disadvantage that the propensity of aluminium to corrode was not fully understood and this did little for their reputation.

4. Aluminium in Nathan’s vessels was replaced by ________
A. Iron
B. Glass
C. Stainless steel
D. Ceramicsid5fdb3a9d084b4″

Answer: C
Clarification: Aluminium in Nathan’s vessel was replaced by stainless steel. Stainless steel consists of a film which is composed of nickel, chromium, etc. which increases the resistance of the vessel to corrosion.

5. What is the diameter of cylindroconical vessel?
A. 1.2 – 3.0 m
B. 4.0 – 4.2 m
C. 5.0 – 5.5 m
D. 3.0 – 4.0 mid5fdb3a9d084be”

Answer: B
Clarification: The diameter of the cylindroconical vessel is 4.0 – 4.2 m. The most common supplied cylindroconical fermentation vessel is of capacity 1500 hl with 12 – 13 m body height, a diameter of 4.0 – 4.2 m and cone with an included angle of 70°. This was reported by Shuttlewood in 1984.

6. The heat transfer is given by ___________
A. Q = UA ΔT
B. U = QA ΔT
C. U = AQ ΔT
D. Q = U ΔTid5fdb3a9d084c8″

Answer: A
Clarification: The transfer of heat from beer to coolant involves the combination of convection and conduction. It can be given by heat transfer formula: Q = UA ΔT where Q is the rate of heat transfer, U is the overall heat transfer coefficient, A is the area of the jacket, and ΔT is the difference in temperature between two liquids.

7. The unit rate of heat transfer (Q) is ____________
A. J/s
B. J m² s^-1 K^-1
C. m²
D. Jid5fdb3a9d084d2″

Answer: A
Clarification: The unit of the rate of heat transfer is Joules per second. It is also known as Watts. J m² s^-1 K^-1 is the unit of heat transfer coefficient and m² is the unit of area of the jacket.

8. Which of the following is not an advantage of single-tank operation?
A. Reduction in process time
B. Avoids tank-to-tank transfer
C. Avoids oxygen pick-up
D. Avoids foam formationid5fdb3a9d084dc”

Answer: D
Clarification: The avoiding of the formation of foam is an advantage of antifoaming agents or defoamers. The most important advantage of single-tank operation is the reduction in total process time, avoids tank-to-tank transfer and therefore avoiding the possibility of oxygen pick-up.

9. Which of the following company developed the Asahi vessels?
A. American
B. Indian
C. Canadian
D. Japaneseid5fdb3a9d084e6″

Answer: D
Clarification: Asahi vessels were developed by the Japanese brewing company during the mid-1960s and were designed for uni-tank operation. After Japan, Asahi vessels were also installed in the United States where they were seen as increasing the fermentation and conditioning capacity.

10. The capacity of Asahi vessels is __________
A. 4000 hl
B. 5000 hl
C. 6000 hl
D. 8000 hlid5fdb3a9d084f0″

Answer: B
Clarification: The capacity of Asahi vessel is 5000 hl and aspect ratio was close to 1. They were made from stainless steel and were cylindrical in shape with an internal diameter of 7.5 m and height 11.8 m.

11. Who described the single-tank operation?
A. Harada
B. Takayanagi
C. Amaha
D. Mauleid5fdb3a9d08512″

Answer: C
Clarification: Amaha et al. in 1997 described the use of single-tank operation. The single-tank operation is more advantageous than two-tank operation as there is a reduction in the total process time in single-tank operation.

12. The Rainier uni-tank was designed in ______________
A. USA
B. England
C. Japan
D. Scotlandid5fdb3a9d0851c”

Answer: A
Clarification: The Rainer uni-tank was designed at the Rainier Brewing Company of Seattle, Washington, USA. It was specially designed for single-tank fermentation and conditioning. Hence the name was given as ‘universal tank’.

13. Spheroconical fermenters have a minimal surface area.
A. True
B. Falseid5fdb3a9d08526″

Answer: A
Clarification: The spheroconical fermenters have a minimal surface area. The sphere offers many advantages as the sphere is optimal geometry for enclosing the maximum volume within a minimal surface area. Hence, it is cost-effective.

14. Yorkshire square fermenter is a two-vessel system.
A. True
B. Falseid5fdb3a9d08530″

Answer: B
Clarification: Yorkshire square fermenter is a one-vessel system. It is a traditional open vessel designed for use with flocculent ale strains. It overcomes the double cleaning disadvantage of the dropping system.

Fermentation Technology online quiz on “Commercial Applications – Surface, Submerged and Solid State Fermentation”.

1. In which of the following the microorganisms grow on the surface of the medium?
A. Submerged fermentation
B. Surface fermentation
C. Solid state fermentation
D. Batch fermentationid5fdb445fee869″

Answer: B
Clarification: In surface fermentation, the microorganisms are allowed to grow on the surface of the liquid culture medium. It is also called as the surface culture fermentation. However, it is time-consuming and requires a large space.

2. Which of the following is not required in surface fermentation?
A. Aeration
B. Baffles
C. Agitation
D. Stirrerid5fdb445fee88b”

Answer: C
Clarification: Agitation is not provided or done in the surface culture fermentation. In this, microorganisms grow on the surface of the liquid medium without agitation. The filtrate is separate from the cell mass and is processed to recover the desired product after an appropriate incubation time.

3. Which of the following grows on the surface of the medium when Aspergillus niger is inoculated?
A. Slime layer
B. Mycelium layer
C. Foam layer
D. Capsuleid5fdb445fee89a”

Answer: B
Clarification: When Aspergillus niger is allowed to grow on the surface of the liquid medium in surface culture fermentation, a layer of mycelium grows on the surface of the medium. It appears as a mycelial mat which is thick and floating over the medium.

4. In which of the following the microorganisms grow inside the medium?
A. Submerged fermentation
B. Surface fermentation
C. Solid state fermentation
D. Batch fermentationid5fdb445fee8a7″

Answer: A
Clarification: In submerged fermentation, the microorganism grows inside the liquid medium. The nutrients or enzymes or reactive compounds which are required for the growth of microorganisms are added to the medium.

5. Which of the following is not true for submerged liquid fermentation?
A. The concentration of media is lower
B. Small-size bioreactors are used
C. Easy sampling
D. Expensive downstream processingid5fdb445fee8b2″

Answer: B
Clarification: Usually in submerged liquid fermentation, the bioreactor used are of larger size because the concentration of media is less and is diluted. The small-sized bioreactors can be used in the solid-state fermentation. However, the sampling is easy for biomass measurement but the downstream processing is difficult and very expensive.

6. Which of the following process proceeds with having a rich fermentation broth and high oxygen concentration?
A. Submerged fermentation
B. Surface fermentation
C. Solid state fermentation
D. Batch fermentationid5fdb445fee8bc”

Answer: A
Clarification: Submerged fermentation proceeds with having a rich fermentation broth and high concentration of oxygen. However, the concentration of broth is very much lower as compared to that of water content and is diluted.

7. Which of the following process occurs in the absence of free liquid?
A. Submerged fermentation
B. Batch fermentation
C. Solid state fermentation
D. Continuous fermentationid5fdb445fee8c7″

Answer: C
Clarification: Solid state fermentation (SSF) occurs in the absence or near absence of free liquid. In this method, the waste products like agro-industrial wastes are utilized as a substrate which is a source of nutrients for the production of products like enzymes, etc.

8. Which of the following is not true of solid state fermentation (SSF)?
A. Easy downstream process
B. Small-size bioreactors are used
C. Greater chances of contamination
D. Less consumption of energyid5fdb445fee8d1″

Answer: C
Clarification: The chances of contamination is low because of less availability of water. However, the chances of contamination are more in submerged liquid fermentation. The consumption of energy is less for gas transfer and small-size bioreactors are used. The downstream processing is cheap, easy and time-saving.

9. Which of the following bioreactor is used in group-1 SSF?
A. Rotating drum
B. Stirred-bed
C. Packed bed
D. Trayid5fdb445fee8dc”

Answer: D
Clarification: Tray bioreactor is used in group-1 solid state fermentation. In group-1, the aeration is not produced naturally and is effortless. Agitation is also not required and is static. Packed bed bioreactors are used in group-2, rotating drum bioreactor is used in group-3, and stirred-bed bioreactor is used in group-4.

10. Which of the following requires a substrate as support?
A. Submerged fermentation
B. Surface fermentation
C. Solid state fermentation
D. Batch fermentationid5fdb445fee8e5″

Answer: C
Clarification: Solid state fermentation (SSF) requires a substrate as solid support. The substrate should be natural and inert and must not be reactive. The substrates like bran, bagasse, and paper pulp are most commonly used.

11. Which of the following physicochemical factor does not affect SSF?
A. Pressure
B. Temperature
C. pH
D. Moisture contentid5fdb445fee8ef”

Answer: A
Clarification: Pressure has no role to play in the affection of SSF. Factors like temperature, pH, moisture content, gaseous environment, aeration, particle size affect the solid-state fermentation.

12. Which of the following bioreactor mix intermittently without forced aeration?
A. Packed-bed bioreactors
B. Rotating drum bioreactors
C. Spouted-bed bioreactors
D. Fluidized-bed bioreactorsid5fdb445fee8f9″

Answer: B
Clarification: Rotating drum bioreactors mix intermittently without forced aeration. It operates on semi-continuous or continuous mode where the rotating drum is a horizontal cylinder filled with a bed of substrate.

13. The concentration of products is low in SSF.
A. True
B. Falseid5fdb445fee903″

Answer: B
Clarification: The concentration of products is high in solid state fermentation (SSF) and the rate of production is also higher and therefore, higher yield. However, the concentration of the product is low in submerged fermentation due to slower production rate and therefore, low yield.

14. SSF occurs in the presence of the liquid medium.
A. True
B. Falseid5fdb445fee90d”

Answer: B
Clarification: Solid state fermentation occurs in the absence of the liquid medium by employing an inert or natural substrate as solid support. The microorganisms are chosen such that it requires less water for growth such as filamentous fungi.

Fermentation Technology for online Quizzes, .

Fermentation Technology Multiple Choice Questions on “Microbial Growth Kinetics – FedBatch Culture”.

1. The Fed-batch culture is a/an ______ culture system.
A. Open
B. Closed
C. Isolated
D. Semi-closedid5fcf61a751315″

Answer: D
Clarification: The Fed-batch culture is a closed culture system where the nutrient media is prepared and it is inoculated with culture organism and then is incubated for a particular time. The batch culture is a closed system and continuous culture is an open system.

2. Who introduced the term “Fed-Batch”?
A. Burrow et al.
B. Bu’Lock et al.
C. Yoshida et al.
D. Maniatis et al.id5fcf61a751338″

Answer: C
Clarification: The term “Fed-Batch” was introduced by Yoshida et al. to describe the cultures which are fed continuously or sequentially without the removal of culture fluid.

3. Which of the following is a type of Fed-Batch culture?
A. Variable volume
B. External Feedback
C. Internal Feedback
D. Chemostatid5fcf61a751353″

Answer: A
Clarification: There are two types of Fed-Batch culture: Variable-volume fed-batch culture and fixed-volume fed-batch culture. The external feedback, internal feedback, chemostat are the types of continuous fermentation.

4. Which scientist(s) described the kinetics of variable-volume fed-batch culture?
A. Dunn and Mor
B. Maniatis et al.
C. Van’t Hoff
D. Maxwellid5fcf61a751369″

Answer: A
Clarification: The kinetics of variable-volume fed-batch culture have been developed by Dunn and Mor in 1975 and Pirt in 1974, 1975, 1979.

5. What happens in a Quasi-Steady state?
A. Specific growth increases
B. Specific growth decreases
C. Specific growth becomes constant
D. Specific growth becomes zeroid5fcf61a751373″

Answer: B
Clarification: In a Quasi-steady state, specific growth gradually decreases. It is a state where all the variables become constant. The Quasi-state approximation is useful in studying the kinetics of certain chemical reactions.

6. What is the condition for a Quasi-Steady state?
A. µ = 0
B. µ = D
C. D = F
D. µ = Fid5fcf61a75137b”

Answer: B
Clarification: Although the total biomass in the culture increases with time, cell concentration(x) remains virtually constant, that is (dx/dt) = 0 and therefore µ = D (approx.). This situation is termed as a Quasi-Steady State.

7. In Variable-volume fed-batch culture, the broth volume remains almost the constant.
A. True
B. Falseid5fcf61a751384″

Answer: B
Clarification: In Variable-volume fed-batch culture, volume changes with fermentation time due to the substrate feed. That is why the name is variable-volume fed-batch culture. Whereas, in fixed-volume fed-batch culture, volume remains the same.

8. Which of the following does not include in the range of fermentation processes?
A. Microbial Enzymes
B. Microbial metabolites
C. Biotransformation
D. Recombinant DNAid5fcf61a75138e”

Answer: D
Clarification: The range of fermentation processes includes microbial enzymes, microbial metabolites, biotransformation, recombinant protein, microbial cells. Recombinant DNA is produced by rDNA technology.

9. Which of the following was used in the production of bakers’ yeast?
A. Batch culture
B. Continuous culture
C. Fed-Batch culture
D. Solid state cultureid5fcf61a751396″

Answer: C
Clarification: Fed-Batch culture was used in the production of bakers’ yeast as early as 1915. Bakers’ yeast is a yeast useful in the production of a variety of bread in the baking industry. Saccharomyces cerevisiae is known as Bakers’ yeast, is useful for the production of yeast and alcohol.

10. Which of the following is correct with respect to Fermentation?
A. A process involving the mass culture of micro-organisms
B. It is a fast process
C. Fermented food products are always healthy
D. Oxygen is produced during fermentationid5fcf61a75139f”

Answer: A
Clarification: Fermentation is a slow process involving the mass culture of micro-organisms, production of alcoholic beverages, food spoilage, growth dependent on substrate-level phosphorylation. Sometimes it can lead it gastric cancer.

11. In fixed-volume fed-batch culture, volume changes with fermentation time due to the substrate feed.
A. True
B. Falseid5fcf61a7513a7″

Answer: B
Clarification: In fixed-volume fed-batch culture, the broth volume remains almost the constant. Hence, the name is fixed-volume. Whereas, in variable-volume fed-batch culture, the volume keeps on changing.

12. Who developed a method for the optimization of the fed-batch system?
A. Shioya
B. Queener
C. Swartz
D. Wakiid5fcf61a7513b0″

Answer: A
Clarification: Shioya in 1990 developed a method for the optimization of fed-batch culture based on the relationship of µ and q_p.

13. Cyclic Fed-Batch culture has been used for the production of _______
A. Bovine serum albumin
B. Penicillin
C. Human serum albumin
D. Cheese Productionid5fcf61a7513b8″

Answer: C
Clarification: Cyclic fed‐batch culture has been used for the production of human serum albumin. Human Serum Albumin is an organic component of blood plasma, which is used to maintain osmotic pressure of blood.

14. What is the unit of substrate feed rate (G)?
A. dm³
B. dm³ h^-1
C. g dm^-3 h^-1
D. g dm³id5fcf61a7513cc”

Answer: C
Clarification: The unit of substrate feed rate G is g dm^-3 h^-1 which is given by the equation,
(dx/dt) * Y = G where Y is the yield factor.

15. The feed solution in fed-batch culture is highly concentrated to _______
A. avoid dilution of the bioreactor
B. maintain low cell density in bioreactor
C. avoid lag phase
D. increase productivityid5fcf61a7513d4″

Answer: A
Clarification: The feed solution in fed-batch culture is highly concentrated to avoid dilution of the bioreactor and to reach high cell density in a bioreactor.

Fermentation Technology Multiple Choice Questions on “Instrumentation and Control – Temperature and Pressure Measurement”.

1. Which of the following sensor penetrates into the fermenter?
A. Exhaust-gas analyzers
B. pH electrodes
C. Tachometers
D. Load cellsid5fdc7db6440c4″

Answer: B
Clarification: The sensors which penetrate into the fermenter are pH electrodes, dissolved-oxygen electrodes, etc. Exhaust gas analyzers work on samples which are continuously withdrawn from the fermenter. Tachometers and Load cells are sensors which do not come in contact with fermentation broth or gases.

2. Which of the following sensor is used to measure the acid/alkali addition?
A. pH
B. Redox
C. Temperature
D. Oxygenid5fdc7db6440e6″

Answer: A
Clarification: The pH is defined as the potential of the hydrogen atom. It is used to measure the concentration of hydrogen or hydroxide ions in a solution. pH electrodes are normally used to measure the acid/alkali addition.

3. Which of the following sensor is used to measure the change in flow rate?
A. Temperature
B. Weight
C. Medium analysis
D. Exit-gas analysisid5fdc7db6440f3″

Answer: B
Clarification: Weight sensors are used to measure the change in flow rate. Along with weight sensors the flow rate sensors are also used to measure the change in flow rate. Temperature is used to measure the hotness or coldness of the medium. Whereas the medium and exit-gas analyzers are used to measure the change in feed rate.

4. The heat control at large-scale in the fermenter is carried out by _________
A. Inter heating coils
B. Heating jacket
C. Controlled bath
D. Cold-water circulationid5fdc7db6440fe”

Answer: D
Clarification: The heat control at large-scale in the fermenter is carried out by cold-water circulation or internal coils. The heat control at small-scale in the fermenter is carried out by a silicone heating jacket, controlled bath, etc.

5. Which of the following temperature sensors is not used for a temperature measurement?
A. Non-electrical type
B. Electrical type
C. Magnetic type
D. Radiation typeid5fdc7db644107″

Answer: C
Clarification: There is no such magnetic type used for the measurement of temperature in the fermentation. The non-electrical type, electric type, radiation types are usually used to measure temperature in fermenters.

6. The resistance _________ with increase in temperature.
A. Increases
B. Decreases
C. Becomes constant
D. Becomes zeroid5fdc7db644110″

Answer: A
Clarification: The resistance of the material increases with an increase in temperature. This happens because the temperature is directly proportional to the change in temperature.

7. Which of the following is made up of mixtures of pure oxides of iron and nickel?
A. Thermistors
B. Mercury thermometers
C. Radiation thermometers
D. Metallic thermometersid5fdc7db64412e”

Answer: A
Clarification: Thermistors are the semiconductors that are made up of pure oxides of iron, nickel or other metals. They exhibit a large change in resistance with a small temperature change. They are highly sensitive with small temperature changes.

8. Which of the following devices is not used for pressure measurement?
A. Diaphragm gauge
B. Pressure bellows
C. Strain gauge
D. Dynamometerid5fdc7db644139″

Answer: D
Clarification: The devices used for the measurement of pressure is diaphragm gauge, strain gauge, pressure bellows, piezoelectric transducer, etc. The dynamometer is useful in agitation measurement and control.

9. Who invented the Bourdon tube?
A. Eugene
B. Howe
C. Flynn
D. Royceid5fdc7db644143″

Answer: A
Clarification: Eugene Bourdon in 1949 invented the Bourdon tube. It has been used in pressure measurement in many processes like fermentation. It is used as a direct indicating gauge.

10. Which of the following measures the pressure with change in electrical resistance?
A. Bourdon tube
B. Pressure bellows
C. Strain gauge
D. Diaphragm gaugeid5fdc7db64414c”

Answer: C
Clarification: The strain gauge measures the pressure with a change in electrical resistance. It uses a wire subjected to strain result in the change in electrical resistance which can be measured.

11. Which of the following sensor is not a part of the fermenter?
A. On-line
B. In-line
C. Off-line
D. Out-lineid5fdc7db644156″

Answer: C
Clarification: Offline sensors are the sensors that are not an integral part of the fermenter. The measured value must be entered for data collection. The on-line and in-line sensors are the integral parts of the fermenter.

12. Which of the following parameters is not useful in the construction of pressure bellows?
A. Hysteresis
B. Sensitive to changing pressures
C. Corrosion
D. pHid5fdc7db64415f”

Answer: D
Clarification: The parameters which are kept in mind while constructing pressure bellows are Hysteresis, sensitive to changing pressures, corrosion, range of pressure, fabrication ease, fatigue on the dynamic operation.

13. Ion-specific sensors are the types of on-line sensors.
A. True
B. Falseid5fdc7db644169″

Answer: A
Clarification: The ion-specific sensors are the type of on-line sensors and are an integral part of the fermenter. The measured value is entered into the control system for controlling the process.

14. Antifoam probe is a type of off-line sensor.
A. True
B. Falseid5fdc7db644172″

Answer: B
Clarification: The antifoam probe is a type of in-line sensors. They are an integral part of the fermenter. It is used to check the foam formation in the fermenter and control it.

15. If the two metals have different temperature coefficient then, they are useful in making _________
A. Manometric thermometer
B. Gas thermometer
C. Bimetallic thermometer
D. Digital thermometerid5fdc7db64417b”

Answer: C
Clarification: The bimetallic thermometer consists of a bimetallic strip which has a different temperature coefficient. It is used to convert temperature into mechanical displacement.