Category: Fermentation Technology Objective Questions

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.

Fermentation Technology Multiple Choice Questions on “Fermentation System – Immobilization”.

1. Which of the following is not an advantage of immobilization?
A. Minimum reaction time
B. Cheap isolation of cells/enzymes
C. Can be reused
D. Less labour inputid5fdfe1b01c098″

Answer: B
Clarification: The advantages of immobilization of cells or enzymes are that it can be reused, and less labour input is required. The reaction time is also less and it is a continuous process but cost for isolation, purification of cells or enzymes is high.

2. Who describes Immobilization as physical confinement of microorganisms?
A. Radovich
B. Godia
C. Scott
D. McMurroughid5fdfe1b01c0d0″

Answer: A
Clarification: Radovich in 1985 defined immobilization as the physical confinement or localization of microorganisms in a way that permits the re-use. It is generally the imprisonment of cells or enzymes in a support/matrix.

3. Which of the following group of scientists described five methods of immobilization?
A. Radovich, Scott, and McMurrough
B. Godia, Scott, and Radovich
C. Radovich, McMurrough, and Godia
D. Godia, Scott, and McMurroughid5fdfe1b01c0df”

Answer: D
Clarification: Godia et al., in 1987; Scott, in 1987; and McMurrough, in 1995 described the five methods of immobilization. These are flocculation, entrapment, attachment, colonization, and retention.

4. Which of the following is a synthetic polymer used as a support/matrix?
A. DEAE Cellulose
B. Collagen
C. Zeolites
D. Starchid5fdfe1b01c0e9″

Answer: A
Clarification: DEAE cellulose is a synthetic polymer used as a support/matrix in immobilization. Polyvinyl chloride (PVC., and UV activated Polyethylene Glycol (PEG) are other synthetic polymers. Collagen and Starch is a natural polymer whereas, zeolite is an inorganic substance.

5. Which of the following is an inorganic material used as support?
A. Pectin
B. Gelatin
C. Ceramics
D. Alginateid5fdfe1b01c0f3″

Answer: C
Clarification: Ceramic is an inorganic material that is used as a support/matrix in during immobilization. Silica, diatomaceous earth, glass, charcoal, activated carbon, etc. are examples of inorganic material which is used as support. Pectin, Gelatin, and alginate are examples of a natural polymer.

6. Which of the following is not a method of immobilization?
A. Entrapment
B. Ionic bonding
C. Adsorption
D. Encapsulationid5fdfe1b01c0fc”

Answer: B
Clarification: Ionic bonding is not a method of immobilization. It is the transfer of electrons between the atoms. Whereas entrapment, adsorption, encapsulation, covalent bonding, and copolymerization are the methods of immobilization.

7. Which of the following bond/interaction is not involved in adsorption?
A. Covalent bond
B. Ionic interaction
C. Hydrogen bond
D. Van der Waals forcesid5fdfe1b01c105″

Answer: A
Clarification: Covalent bonding is not involved in adsorption as it is the strongest bond and adsorption proceeds with weaker bonds. Ionic interaction, Hydrogen bonding, Van der Waals forces are the weaker bonds or interaction involved in adsorption.

8. In which of the following process carrier is placed near to an electrode?
A. Static process
B. Dynamic process
C. Reactor loading process
D. Electrode position processid5fdfe1b01c10f”

Answer: D
Clarification: In the electrode position process, the carrier is placed proximal to an electrode in the enzyme bath and the current is put on. The enzyme migrates to the carrier and is deposited on the surface.

9. Which of the following support/carrier is not used in the covalent bonding method?
A. Phenol rings
B. Thiol groups
C. Carbonyl groups
D. Hydroxyl groupsid5fdfe1b01c118″

Answer: C
Clarification: Carbonyl groups are not used as a support/matrix in the covalent bonding method of immobilization. Phenol ring of tyrosine, the Hydroxyl group of serine, Thiol group of cysteine, etc. are used as a matrix for covalent bonding.

10. Which of the following is not a method of entrapment?
A. Inclusion in gels
B. Diazotization
C. Inclusion in fibers
D. Inclusion in microcapsulesid5fdfe1b01c120″

Answer: B
Clarification: Diazotization is a method of covalent bonding of immobilization. Inclusion in gels, fibers, and microcapsules are the methods of entrapment which involves trapping of cells/enzymes in gels, fibers, and microcapsules respectively.

11. Which of the following method does not require support/matrix material?
A. Cross-linking
B. Entrapment
C. Adsorption
D. Covalent bondingid5fdfe1b01c129″

Answer: A
Clarification: Cross-linking is a method of immobilization which does not require the support/matrix material. The cross-linking occurs between groups of cells/enzymes via polyfunctional reagents. Entrapment, adsorption, and covalent bonding require the use of support/matrix materials.

12. Who described the production of alcohol-free beer?
A. Florante
B. Frederic
C. Dieren
D. Scottid5fdfe1b01c132″

Answer: C
Clarification: Dieren in 1995 along with Mieth described the production of alcohol-free beer. The yeast was immobilized on DEAE Cellulose and contained within a specifically designed vessel termed ‘Immocon’ bioreactor.

13. A peptide bond is formed between amino and carbonyl groups.
A. True
B. Falseid5fdfe1b01c13b”

Answer: B
Clarification: A peptide bond is formed between the amino group and a carboxyl group. When one molecule with a carboxyl group reacts with the amino group of another molecule, a molecule of water is released and a peptide bond is formed between two molecules.

14. The reactor loading process is a method of adsorption.
A. True
B. Falseid5fdfe1b01c143″

Answer: A
Clarification: The reactor loading process is a method of adsorption where the carrier is placed in the reactor and then enzyme/cell is transferred to the reactor. Other methods of adsorption include static process, dynamic batch process, and electrode position process.