Category: Fermentation Technology Objective Questions

Fermentation Technology Multiple Choice Questions on “Effluent – Treatment Processes”.

1. Which of the following is the method for disposal of municipal solid waste?
A. Incineration
B. Landfilling
C. Well disposal
D. Spray irrigationid5fdb418307987″

Answer: B
Clarification: Landfilling is the method for disposal of municipal solid waste and industrial waste. The waste is deposited into natural or manmade voids. For e.g. in disused clay pits, both solids and liquid wastes can be deposited.

2. Which of the following is not a factor to investigate in a site survey?
A. BOD/COD
B. Sterility
C. Colour
D. Radioactivityid5fdb4183079aa”

Answer: B
Clarification: The factors like BOD/COD, Colour, Radioactivity, Hardness, Odour, tastes, Turbidity, Detergents, Toxins, etc. are the important factors to investigate in a site survey.

3. Who described the disposal of antibodies and steroid wastes?
A. Colovos and Tinklenberg
B. Zajic and Melcher
C. Smith
D. Mbagwu and Ekwealorid5fdb4183079bb”

Answer: A
Clarification: Colovos and Tinklenberg described the disposal of antibodies and steroid wastes with Biochemical Oxygen Demand of 5,000 to 20,000 dm^-3. They were first chlorinated to lower the BOD and reduce unpleasant odours and then sprayed to the land until rainfall was reached.

4. Which of the following is a primary treatment?
A. Sedimentation
B. Activated sludge
C. Sand filters
D. Microstrainersid5fdb4183079c7″

Answer: A
Clarification: Primary treatment includes physical and chemical methods like sedimentation, coagulation, etc. It will considerably reduce the Biochemical Oxygen Demand of the resulting effluent.

5. What is the function of a sedimentation tank?
A. Removal of larger suspended matter
B. Reduction in particle size
C. Removal of grit
D. Removal of finer matterid5fdb4183079d3″

Answer: D
Clarification: The sedimentation tanks are used for the removal of finer matter. They are generally circular or rectangular flow tanks. They operate at retention times of 6-15 hours with the facility of continuous removal of settled sludge.

6. Which is the use of comminutors?
A. To reduce the size of particles
B. To remove the grit
C. To remove large particles
D. To remove small particlesid5fdb4183079dd”

Answer: A
Clarification: Sewage Grinders are also known as comminutors used in the wastewater treatment plants and pumping stations. They help in the breakdown of larger solids into the smaller ones.

7. The diameter of a conventional trickling filter is _______
A. 5-8 m
B. 5-10 m
C. 1-10 m
D. 8-16 mid5fdb4183079ec”

Answer: D
Clarification: A conventional trickling filter has a diameter of 8-16 m. It consists of a cylindrical concrete tank 2-3 m in depth. Some of the filters are rectangular in shape. It is achieved mainly aerobically.

8. Who described the use of contactors in wastewater treatment?
A. Ware and Pescod
B. Arden and Lockett
C. Cooper and Wheeldon
D. Taylor and Seniorid5fdb4183079fe”

Answer: A
Clarification: Ware and Pescod in 1989 described the use of contactors. The full scale aerobic/anaerobic rotating biological contactors are used to remove or treat the brewery wastewaters. More than 85% of COD was removed in the aerobic stage.

9. What is the use of venturi?
A. To generate low-pressure
B. To remove grit
C. To generate high pressure
D. To break the foamid5fdb418307a0f”

Answer: A
Clarification: The venturi is a system for increasing the speed of the liquid by constricting its shape. A Venturi injector is based on a fluid flow that causes low pressure at an inlet port. Thus, low-pressure can be generated from a high-pressure flow.

10. Which of the following is not the use of anaerobic treatment?
A. Achieving higher loading rates
B. Low power to treat BOD
C. The metabolization of organic matter
D. High levels of microbial growthid5fdb418307a25″

Answer: D
Clarification: There are many reasons for using anaerobic processes for waste treatment. It is useful in achieving a higher loading rate, low power BOD treatment, organic matter is metabolized into a stable form, ease of handling, low levels of microbial growth due to the anaerobic process.

11. UASB was developed in __________
A. America
B. Netherlands
C. London
D. Japanid5fdb418307a2e”

Answer: B
Clarification: Up-Flow Anaerobic Sludge Blankets (UASB. was a system developed in the Netherlands. In this system, very high-levels of biomass is retained in the reactor by flocculation. In this, no support media is added to the reactors and it acts as a fluidized-bed.

12. Velocity channels are used to remove larger suspended particles.
A. True
B. Falseid5fdb418307a38″

Answer: B
Clarification: Screening is done to remove larger suspended particles and floating matter. The constant velocity channels are used to remove grit to prevent further damage to the plant in later processes. It has a velocity of 0.3 m/s.

13. Trickling filters are less suitable for a larger volume of effluents.
A. True
B. Falseid5fdb418307a41″

Answer: A
Clarification: The trickling filters are less suitable for a larger volume of industrial effluent because it does not have a high specific area and high voltage. Large areas are required for a larger volume of strong effluents. Towers are used as an alternative.

14. Which of the following is used where there is no oxygen supply?
A. Comminutors
B. Sedimentation tank
C. Mechanical mixer
D. Screening devicesid5fdb418307a4a”

Answer: C
Clarification: If there is no oxygen supply via spargers, the baffles must be provided to avoid the formation of layers. Baffles are also used to increase the rate of agitation and aeration. It is also used to provide cooling.

15. The temperature of 20°C is used to take BOD of _________
A. 7-days
B. 10-days
C. 5- days
D. 1-dayid5fdb418307a5f”

Answer: C
Clarification: The temperature of 20°C is used to take BOD of 5 days because in 5 days the dissolved oxygen present in water is consumed for the decomposition of organic matter. Hence 5 day BOD is used as a standard to represent the amount of oxygen dissolved.

Fermentation Technology Multiple Choice Questions on “Brewing Yeast – Taxonomy and Location of Enzymes”.

1. What is the location of alcohol acetyltransferase?
A. Lysosomes
B. Microsomes
C. Peroxisomes
D. ERid5fdba5504c2fa”

Answer: B
Clarification: Alcohol acetyltransferase is present in microsomes. Microsomes are re-formed pieces of the endoplasmic reticulum (ER) when eukaryotic cells are broken down. They are not present in healthy living cells.

2. Which of the following enzyme is present in the plasma membrane?
A. Invertase
B. Melibiase
C. Steryl-ester hydrolase
D. Hexokinaseid5fdba5504c31f”

Answer: C
Clarification: Steryl-ester hydrolase is present in the plasma membrane. Whereas melibiase and invertase are present in periplasm and Hexokinase is present in the cytoplasm of the cell. It helps in the biosynthesis of bile acids.

3. Saccharomyces cerevisiae belongs to the division _____________
A. Oomycota
B. Zygomycota
C. Basidiomycota
D. Ascomycotaid5fdba5504c32f”

Answer: D
Clarification: Saccharomyces cerevisiae belongs to the division Ascomycota. The members of division Ascomycota are commonly known as sac fungi or Ascomycetes and it is the largest phylum of Fungi with 64,000 species.

4. Imperfect fungi belongs to ___________
A. Oomycota
B. Zygomycota
C. Basidiomycota
D. Deuteromycotaid5fdba5504c33b”

Answer: D
Clarification: Fungi imperfecti belong to Deuteromycota. They do not produce spores and the member of Deuteromycota are known as Deuteromycetes. Penicillium is an example of Deuteromycetes.

5. Oomycota are ______________
A. Parasitic to plants
B. Imperfect fungi
C. Insect parasites
D. Filamentousid5fdba5504c346″

Answer: A
Clarification: Oomycota is a fungal division that resembles algae and is often parasitic to plants. The member of division oomycota are known as oomycetes and examples are white rust, water mould and downy mildew.

6. Black bread mould is an example of kingdom _____________
A. Basidiomycota
B. Deuteromycota
C. Zygomycota
D. Ascomycotaid5fdba5504c351″

Answer: C
Clarification: Black bread mould is an example of kingdom Zygomycota. The members of kingdom Zygomycota are filamentous and are insect parasites and are referred to as zygomycetes.

7. Which of the following is an example of Basidiomycota?
A. White rust
B. Water mould
C. Corn smut
D. Thrushid5fdba5504c35b”

Answer: C
Clarification: Corn smut is an example of Basidiomycota. It is a type of plant disease caused by the pathogenic fungus. Other examples of Basidiomycota include Sulphur fungus, black stem rust, puffball, etc.

8. Which of the following enzyme is present in Vacuole?
A. Acid trehalase
B. PDH
C. Proline oxidase
D. Fumaraseid5fdba5504c365″

Answer: A
Clarification: Acid trehalase enzyme is present inside the vacuoles. It is an important enzyme which is useful in the conversion of trehalose to glucose. It is also present inside the small intestine of human beings.

9. TCA cycle enzymes are located in ____________
A. Vacuoles
B. Golgi Apparatus
C. Mitochondrial matrix
D. Plasma membraneid5fdba5504c36f”

Answer: C
Clarification: TCA cycle enzymes are located in the mitochondrial matrix. It is the space between the inner membrane of mitochondria and is more viscous than the cytoplasm of the cell.

10. Who is ‘the father of taxonomy’?
A. Lamarck
B. Darwin
C. Linnaeus
D. Leeuwenhoekid5fdba5504c37a”

Answer: C
Clarification: Carl Linnaeus is the father of taxonomy. He was a Swedish botanist, physician, and zoologist who formalized binomial nomenclature, which is the modern system of naming organisms.

11. The group of division is known as ____________
A. Kingdom
B. Family
C. Order
D. Genusid5fdba5504c384″

Answer: A
Clarification: The group of division is known as the Kingdom. It is ranked just below the domain. The commonly recognized kingdoms are Protista, Animalia, Plantae, and Fungi. The archaea and bacteria are grouped into one kingdom.

12. Which of the following is the method of raising the temperature of mash contents?
A. Underback
B. Underletting
C. Sparging
D. Enzyme additionid5fdba5504c38e”

Answer: B
Clarification: Underletting is the method of raising the temperature of the contents of the mash tun by pumping hot liquor from the base. Underback is a vessel in which sweet wort is collected from the mash tun and held before delivery to the copper. Sparging is the method of providing air to the medium. An enzyme addition is increasing the rate of a reaction.

13. Diazonium is used to differentiate between Ascomycetes and Deuteromycetes.
A. True
B. Falseid5fdba5504c398″

Answer: B
Clarification: Diazonium Blue B is used to differentiate between ascomycetes and basidiomycetes. The ascomycetes form asci and basidiomycetes form basidia.

14. Carl Linnaeus first classified organisms.
A. True
B. Falseid5fdba5504c3a1″

Answer: B
Clarification: Aristotle first classified organisms. He developed the system of classification of animals and plants. He is also regarded as ‘the father of science’.

Fermentation Technology Multiple Choice Questions on “LAB and Fermented Vegetables”.

1. Which of the following is the most common LAB found on all the plants?
A. Streptococcus pyogenes
B. Lueconostoc mesenteroides
C. Staphylococcus aureus
D. Lactobacillus acidophilusid5fe6b636d57ed”

Answer: B
Clarification: Lueconostoc mesenteroides is the most common Lactic Acid Bacteria found on all the plants. It is although present in relatively low number, averaging about less than 1 percent of plant’s total microbial population.

2. Which of the following are a heterofermentative bacterial species?
A. Lueconostoc spp.
B. Enterococcus spp.
C. Pediococcus spp.
D. Streptococcus spp.id5fe6b636d581d”

Answer: A
Clarification: Lueconostoc spp. is a heterofermentative bacterial species. If they are added to its primary product, lactic acid, then it produces significant quantities of secondary products like alcohol, acetic acid, etc.

3. Which of the following is a homofermentative lactic acid bacteria?
A. Lactobacillus brevis
B. Lueconostoc mesenteroides
C. Lactobacillus fermentum
D. Lactobacillus delbruckiiid5fe6b636d582a”

Answer: D
Clarification: Lactobacillus delbruckii is a homofermentative lactic acid bacteria. They are used in the dairy starter culture applications where the rapid development lactic and reduced pH is desirable.

4. Lactic Acid Fermentation is the most effective strategy for ___________
A. Increasing the quantity of food
B. Preparation of brown bread
C. Food preservation
D. Production of beerid5fe6b636d5834″

Answer: C
Clarification: Lactic Acid Fermentation is the most effective strategy for the preservation of food and safety. The lactic acid produced by LAB is effective in inhibiting the growth of other bacterial species which contaminate and decompose the food. Thus, Lactic Acid Fermentation is an effective strategy.

5. Which of the following substrate cannot be utilized by the LAB to produce gas?
A. Citrate
B. Gluconate
C. Amino acids
D. Alkanesid5fe6b636d583d”

Answer: D
Clarification: Alkanes cannot be used as a substrate by Lactic Acid Bacteria to produce the gas. Citrate, Gluconate, and amino acids are used as the substrate by lactic acid bacteria in the production of gas. They are used to provide flavor to food products.

6. Which class of bacteriocin from LAB produces acidocin B?
A. Class I
B. Class IIa
C. Class IIc
D. Class IIdid5fe6b636d5845″

Answer: C
Clarification: Class IIc of bacteriocin from lactic acid bacteria produces acidocin B. It is produced by Lactobacillus acidophilus. Acidocin B affects membrane permeability and cell wall formation.

7. Which of the following bacteria produces pediocin PA1?
A. Lactobacillus delbruckii
B. Lactobacillus acidophilus
C. Leuconostoc gelidum
D. Lactobacillus helveticusid5fe6b636d584d”

Answer: C
Clarification: Leuconostoc gelidum produces the bacteriocin pediocin PA1. It belongs to the class IIa of bacteriocin and is heat stable, non-modified, cationic with hydrophobic peptides. It contains a double-glycine layer peptide and pediocin-like peptides.

8. Which of the following uropathogen is a target for Lactobacillus vurvatus?
A. Escherichia coli
B. Candida albicans
C. Pseudomonas aeruginosa
D. Staphylococcus aureusid5fe6b636d5857″

Answer: B
Clarification: Candida albicans is a uropathogen which is present in the urinary tract and causes urinary tract infection. Lactobacillus vurvatus is a lactic acid bacterium which targets Candida albicans and controls them by using lactic acid and hydrogen peroxide.

9. Sauerkraut was originated in ___________
A. Germany
B. England
C. America
D. Japanid5fe6b636d585f”

Answer: A
Clarification: Sauerkraut was originated in Germany which was prepared from cabbage and salt as a major ingredient. It is eaten as a salad and has a sour taste with clean acid flavor.

10. Which of the following is used in the production of Gundruk?
A. Cabbage
B. Cauliflower
C. Tomato
D. Potatoid5fe6b636d5866″

Answer: B
Clarification: The fermentation of green leafy vegetables like cauliflower, mustard, radish, etc. is used in the production of Gundruk. The fermentation is initiated by Lactobacillus plantarum and Lactobacillus cellobiosus.

11. Which of the following is not the importance of fermented vegetables?
A. Detoxification
B. Improved Quality
C. Improved Quantity
D. Preservationid5fe6b636d586e”

Answer: C
Clarification: Quantity cannot be increased by fermentation of vegetables. However, the quality of the food can be improved by using substrates with high vitamins. Preservation and detoxification reduce the anti-nutritional properties in vegetables.

12. Sinki is the most popular fermented food in ______________
A. Nepal
B. Japan
C. China
D. Thailandid5fe6b636d5876″

Answer: A
Clarification: Sinki is a radish pickle which is prepared from radish tap roots. It is one of the most popular pickles in Nepal. It is also consumed in India, Nepal, and Bhutan. It is used as a base for soup or eaten a pickle.

13. Homofermentative LAB produces more amount of lactic acid than heterofermentative LAB.
A. True
B. Falseid5fe6b636d587e”

Answer: A
Clarification: Homofermentative LAB produce more amount of lactic acid than heterofermentative LAB. About 85% of lactic acid is produced by homofermentative LAB. An example of homofermentative LAB is Lactobacillus plantarum.

14. Lactobacillus acidophilus is present in the human intestine.
A. True
B. Falseid5fe6b636d5886″

Answer: A
Clarification: Lactobacillus acidophilus is present in the human intestine. It has several roles in the human intestine.

Fermentation Technology Multiple Choice Questions on “Batch Sterilization”.

1. Which of the following is not a type of sterilization?
A. Batch
B. Continuous
C. Filter
D. Submergedid5fcfc695981c2″

Answer: D
Clarification: The types of sterilizations are Batch sterilization, Continuous sterilization, Filter sterilization. Submerged is a type of fermentation where microorganisms are grown in the liquid medium.

2. What do you mean by sterilization?
A. Purification of products
B. Recovery of products
C. Elimination of contamination
D. Formulation of mediaid5fcfc695981e3″

Answer: C
Clarification: Sterilization is the process of removal of unwanted organisms like bacteria, fungi, etc. from the fermentation medium. Purification and recovery of products are part of downstream processing and formulation of media is the preparation of the fermentation media.

3. Which of the following instrument works on the principle of batch sterilization?
A. Incubator
B. Autoclave
C. Centrifuge
D. LAFid5fcfc695981f1″

Answer: B
Clarification: Autoclave is an instrument that works on the principle of batch sterilization. It is used to kill germs which invade the fermentation media. The incubator provides optimum conditions for the growth of microorganisms. Laminar Air Flow (LAF) prevents the contamination of biological samples. A centrifuge is used in the separation of liquids or gases.

4. The highest feasible temperature for batch sterilization is ________
A. 124°C
B. 120°C
C. 122°C
D. 121°Cid5fcfc69598213″

Answer: D
Clarification: The highest temperature, which appears to be feasible for batch sterilization is 121°C so the procedure should be designed such that exposure of the medium to this temperature is kept to a minimum. The nutrients might get depleted if there is a long exposure.

5. The destruction of microorganisms by moist heat is described by ______________
A. Zero-order reaction
B. First-order reaction
C. Third-order reaction
D. Second-order reactionid5fcfc6959821e”

Answer: B
Clarification: The destruction of microorganisms by moist heat or stream is described by First-order reaction and may be represented by the equation, -dN/dt = kN, where N is the number of viable organisms, t is the time of sterilization and reaction rate constant.

6. The contamination can be avoided by sterilizing the fermenter vessels only.
A. True
B. Falseid5fcfc69598228″

Answer: B
Clarification: The contamination can be avoided by sterilizing the fermenter, using pure inoculum to start the fermentation, sterilizing the medium, sterilizing all the components of the fermenter, and maintaining the aseptic conditions.

7. If the foreign microorganism invades the fermentation, which of the following is not likely to occur?
A. The medium will not allow the growth of contaminant
B. The contaminant may outgrow the production organism
C. The contaminant may contaminate the final product
D. The contaminant may degrade the final productid5fcfc69598232″

Answer: A
Clarification: If the foreign microorganism invades the fermenter, the medium will allow the growth of the contaminant along with the production organism. In case, it may outgrow the production organism and contaminate or degrade the final product of the fermenter.

8. Which of the following reaction occurs during the sterilization which results in browning of media?
A. Sandmeyer reaction
B. Maillard reaction
C. Cannizzaro reaction
D. Gattermann reactionid5fcfc6959823c”

Answer: B
Clarification: Maillard reaction is the most common reaction which occurs during the sterilization process. It results in the browning of the medium as well as the nutrient quality is degraded. The other three- Sandmeyer, Cannizzaro, Gattermann- are the types of organic chemical reactions.

9. The long exposure of batch sterilization may lead to ____________
A. Purification of media
B. Recovery of media
C. Degradation
D. Good quality of productid5fcfc69598246″

Answer: C
Clarification: The long exposure of batch sterilization may lead to degradation of the medium. The medium may lose all its nutritional quality. The heat labile components like proteins, vitamins get degraded due to overheating.

10. Which scientists introduced the term ‘Del factor’?
A. Deindoerfer and Humphrey
B. Jacob and Monod
C. Banks and Corbett
D. Richardsid5fcfc69598250″

Answer: A
Clarification: The ‘Del Factor’ was introduced by Deindoerfer and Humphrey as a design criterion for sterilization. It is also called the Nabla factor, sterilization criterion and is represented by the term ∇.

11. What is the advantage of batch sterilization over continuous sterilization?
A. Superior maintenance of medium quality
B. Ease of scale-up
C. Automatic control
D. Lower equipment costsid5fcfc69598259″

Answer: D
Clarification: The advantage of batch sterilization over continuous sterilization is that it has lower capital of equipment costs. Whereas the medium quality, automatic control, ease of scale-up are the advantages of continuous sterilization.

12. The equation for Del factor is _____________
A. ∇ = ln (N₀/N_t)
B. ∇ = ln (N_t/N₀)
C. ∇ = ln (N₀)
D. ∇ = ln (N₀N_t)id5fcfc69598263″

Answer: A
Clarification: The Del Factor is expressed as, ∇ = ln (N₀/N_t), where N₀ is the number of viable organisms present initially at the time of sterilization treatment and N_t is the number of viable organisms after the treatment.

13. The Del Factor decreases as the initial number of organisms _____________
A. Decreases
B. Increases
C. Remains constant
D. Becomes zeroid5fcfc6959826c”

Answer: A
Clarification: The Del factor decreases as the initial number of viable organisms decreases. This happens because the Del factor is directly proportional to the initial number of viable organisms and is inversely proportional to the viable organisms after the sterilization treatment. That is why it decreases.

14. How long does it take for the autoclave to complete its cycle?
A. 30-35 minutes
B. 50 min to 1 hr
C. 15-20 minutes
D. 10-15 minutesid5fcfc69598275″

Answer: C
Clarification: The autoclave completes its cycle within 15-20 minutes at 121°C. An autoclave is similar to a pressure cooker that uses steam to kill the germs. An autoclave can sterilize solids, liquids, etc.

15. The Del factor increases with an increase in the size of the fermenter.
A. True
B. Falseid5fcfc6959827f”

Answer: A
Clarification: The Del factor is directly proportional to the number of viable organisms at the start of the sterilization process. Thus, if the size of fermenter increases, the number of starting organisms will also increase and this leads to an increase in the Del factor.

Fermentation Technology Multiple Choice Questions on “Types of Bioreactors”.

1. In World War II, the fermentation was used for the production of _____________
A. Alcohol
B. Antibiotics
C. Wine
D. Beerid5fdc77a5cdf9b”

Answer: B
Clarification: In World War Two, the bioreactor was used in the production of antibiotics. The development of fermentation came after the 1940s onwards, till then it was used in the production of potable alcohol.

2. The small-scale bioreactors have volume of __________
A. 5-10 litres
B. 10-20 litres
C. 1-10 litres
D. 1-20 litresid5fdc77a5cdfcf”

Answer: D
Clarification: The small-scale bioreactors normally have a volume of 1-20 litres. The bioreactor is used for a number of purposes, scale-up and scale-down studies, clone selection, medium development, process development, etc.

3. The bioreactor is not capable of ______________
A. Producing aseptic conditions
B. Meeting containment regulations
C. Controlling pH
D. Produce electricityid5fdc77a5cdfdf”

Answer: D
Clarification: The bioreactor is not capable of producing electricity. However, it is capable of producing aseptic conditions for longer periods of time, meeting containment regulations, monitoring or controlling pH, temperature, DO, etc.

4. Which of the following fermenters are characterized by height to diameter ratio?
A. Tower fermenter
B. Airlift fermenter
C. Hollow fibre
D. Perfusion bioreactorid5fdc77a5cdfeb”

Answer: A
Clarification: Tower fermenters are the vessels which are characterized by a high height-to-diameter ratio anywhere around 6:1 to 15:1. Aeration is provided by gas sparging via a sample sparger near the fermenter base.

5. In which of the following fermenters the impellers are replaced by the constant flow of gas?
A. Airlift fermenter
B. Tower fermenter
C. Hollow fibre
D. Perfusion bioreactorid5fdc77a5cdff6″

Answer: A
Clarification: In airlift fermenters, the impellers, motors, the driveshaft is replaced by a constant flow of gas introduced into a riser tube. It may also be provided with baffles for improving the mixing efficiency.

6. Which of the following is used to grow anchorage-dependent cells?
A. Airlift fermenter
B. Tower fermenter
C. Hollow fibre chamber
D. Perfusion bioreactorid5fdc77a5ce000″

Answer: C
Clarification: Hollow fibre chambers are used to grow anchorage-dependent cells. It consists of a bundle of fibres and the cells grow with extra capillary spaces within a cartridge.

7. Which of the following bioreactor consists of a vessel replaced by a multilayered bag?
A. Single Use bioreactors
B. Perfusion bioreactors
C. Airlift bioreactor
D. Tower bioreactorid5fdc77a5ce00a”

Answer: A
Clarification: A single-use bioreactor consists of a vessel replaced by a multi-layered bag. It meets all the criteria for a product in contact with a biological process like leaching or chelating.

8. What is the function of carbon in stainless steel?
A. Improves resistance to corrosion
B. Improves ductility
C. Reduces sensitization
D. Improves halogen resistanceid5fdc77a5ce016″

Answer: C
Clarification: The carbon reduces the sensitization when present in stainless steel. It is a maximum of 0.03 % which prevents the precipitation of carbon during welding.

9. The Borosilicate glass does not contain ________
A. SiO₂
B. B₂O₃
C. Al₂O₃
D. KH₂PO₄id5fdc77a5ce020″

Answer: D
Clarification: Borosilicate glass is chemically inert, easy to clean and robust. The glass is made up of SiO₂ 81 %, B₂O₃ 13 % ,NaO₂ + K₂O 4 % and Al₂O₃ 2 %. It has to meet the criteria for the thickness of the glass, the number of air bubbles within the glass and the number of bubbles on the surface.

10. Which of the following class consists of microorganisms which are not causative agents?
A. EFB Class 1
B. EFB Class 2
C. EFB Class 3
D. EFB Class 4id5fdc77a5ce02b”

Answer: A
Clarification: Microorganisms that have never been identified as causative agents of disease in man are termed as harmless microorganisms and belong to EFB Class 1 and do not offer a threat to the environment.

11. Which of the following class consists of microorganisms which are causing disease in man and are hazardous to workers?
A. EFB Class 3
B. EFB Class 1
C. EFB Class 2
D. EFB Class 4id5fdc77a5ce035″

Answer: C
Clarification: Microorganisms that may cause disease in man and are, therefore, hazardous to laboratory workers. They do not spread in the environment. Prophylactics are used for the treatment. They are called low-risk microorganisms.

12. EFB Class 4 consists of ___________
A. Low-risk microorganisms
B. High-risk microorganisms
C. Medium-risk microorganisms
D. Environmental-risk microorganismsid5fdc77a5ce03f”

Answer: B
Clarification: EFB Class 4 consists of High-risk microorganisms. These are microorganisms that cause severe illness to the microorganisms and are very hazardous to people at work. No effective treatment is available for this class.

13. Which of the following class of microorganisms causes less threat to a man?
A. Low-risk microorganisms
B. High-risk microorganisms
C. Medium-risk microorganisms
D. Environmental-risk microorganismsid5fdc77a5ce049″

Answer: D
Clarification: Microorganisms cause less threat to man and are very hazardous to the environment. They are also called as environmental-risk microorganisms and are responsible for high economic losses.

14. In a bubble column reactor, the mass transfer depends on the size of the bubble.
A. True
B. Falseid5fdc77a5ce053″

Answer: A
Clarification: In a bubble column reactor, the hydrodynamics and mass transfer depends on the size of the bubbles and their release from the sparger. It is used in the production of Bakers’ yeast, Beer, and Vinegar. It is also used in aeration and treatment of wastewater.

15. Bubble column reactor provides better mixing than airlift reactors.
A. True
B. Falseid5fdc77a5ce05d”

Answer: B
Clarification: The airlift bioreactors provide better mixing than bubble column reactors. The airlift bioreactors provide a configuration of a greater degree of stability to liquid flow compared with bubble columns. Therefore, higher gas flow rates can be used without incurring operating problems like spray formation.

Tough Fermentation Technology Questions and Answers on “Brewing Yeast – Differentiation (Traditional Methods)”.

1. Which of the following is not a traditional method of differentiation?
A. Plate test
B. Genetic fingerprinting
C. Flocculation test
D. Assimilationid5fdba54ee580f”

Answer: B
Clarification: Genetic fingerprinting is not a traditional method of differentiation. It is a modern method. Plate tests, flocculation tests, assimilation, etc are traditional methods that are based on conventional brewing microbiology.

2. Which of the following is not a reason why modern methods cannot replace traditional methods?
A. High capital costs
B. High skill sets are required
C. Benefit is high
D. High revenue costsid5fdba54ee5834″

Answer: C
Clarification: Modern methods cannot replace traditional methods mainly due to three reasons: The revenue and capital costs of modern methods are higher, the required skill sets are not found in brewery QA laboratories, and the overall cost benefit is not attractive.

3. IRR1 gene is responsible for _____________
A. Growth on solid media
B. Growth on liquid media
C. Release of enzymes
D. Protein synthesisid5fdba54ee5843″

Answer: A
Clarification: IRR1 gene is responsible for the growth or formation of colonies on solid media but it has no role to play on growth in liquid culture. It is neither responsible for the release of the enzyme nor the synthesis of proteins.

4. Which of the following is the most traditional of the ‘traditional methods’ of strain characterization?
A. Genetic fingerprinting
B. Assimilation
C. Flocculation test
D. Giant colony methodid5fdba54ee584f”

Answer: D
Clarification: Giant colony method is the most traditional method of the traditional methods of strain characterization. Lindner reported that up to ten single colonies on thick wort-gelatin plates give rise to ‘giant colonies’ when incubated for three weeks at 18°C.

5. Which of the following is not correct for WLN agar?
A. It is used in the detection of yeasts
B. It is used in the detection of viruses
C. It is a chromogenic media
D. It is used in the detection of bacteriaid5fdba54ee585a”

Answer: B
Clarification: WLN agar is a chromogenic agar that is used in the detection of yeasts and bacteria. The colour of colonies grown on WLN media ranges from light lime green to dark green. The colony colour is used in the differentiation of yeasts.

6. The antibiotic cycloheximide inhibits ____________
A. RNA synthesis
B. DNA synthesis
C. Protein synthesis
D. DNA replicationid5fdba54ee5865″

Answer: C
Clarification: The antibiotic cycloheximide inhibits cytoplasmic protein synthesis in yeasts and other eukaryotes. The resistance to cycloheximide is used in the differentiation of the brewing strains of yeasts.

7. Which of the following does not generate an immune response?
A. Virus
B. Bacteria
C. Haptens
D. Antigenid5fdba54ee586f”

Answer: C
Clarification: Haptens are the substances which are immunogens but do not generate an immune response and are not immunogenic. If haptens are bound to any larger molecule like Bovine Serum Albumin (BSA., it will lead to the formation of protein-carrier complex. This complex is immunogenic in nature and thus generates an immune response.

8. T cells mature in __________
A. Bone marrow
B. Thymus
C. Lymph nodes
D. Spleenid5fdba54ee587b”

Answer: B
Clarification: T cells are T-lymphocytes that are formed inside the bone marrow and for maturation they travel to the thymus. They become single positive after maturation and then the selection of T-cells is initiated.

9. Which of the following is not correct for antigen?
A. It is a foreign molecule
B. It is an immunogen
C. It is always immunogenic
D. It possesses epitopesid5fdba54ee5885″

Answer: C
Clarification: An antigen is any foreign molecule that generates a specific immune response. It is not always immunogenic (e.g. haptens). They are also called as immunogens and they possess epitopes on which a specific antibody molecule attaches itself.

10. B cells are formed in ____________
A. Bone marrow
B. Thymus
C. Spleen
D. Lymph nodesid5fdba54ee588f”

Answer: A
Clarification: B-cells are formed in the bone marrow and even mature inside the bone marrow. They are also known as B-lymphocytes and are Antigen Presenting Cell (APC.. They secrete antibodies in response to antigens.

11. The mutants can be easily searched by using _____________
A. Pour plate technique
B. Spread plate technique
C. Replica plate technique
D. Streak plate techniqueid5fdba54ee5899″

Answer: C
Clarification: The mutants can be easily searched by using a replica plate technique. It involves the transfer of colonies from the master plate to a variety of agar plates such as an antibiotic-resistant plate. The colonies which grow on both the master plate and the replica plate are antibiotic-resistant mutants.

12. ELISA cannot be used in _________
A. Determining the concentration of antigen
B. Determining the concentration of antibody
C. Detection of cancer
D. Viewing of DNAid5fdba54ee58a3″

Answer: D
Clarification: ELISA is an Enzyme-Linked ImmunoSorbent Assay. It is useful in determining the concentration of antigen and antibody. It also has an application in the detection of cancer. However, it is not useful in the viewing of DNA. UV transilluminator is used for DNA viewing.

13. Ale strains have higher maximum growth temperature than lager strains.
A. True
B. Falseid5fdba54ee58ad”

Answer: A
Clarification: Ale strains and lager strains can be easily differentiated by incubating at the temperature 37-38°C. Ale strains have a maximum growth temperature of 37.5 to 39.8°C. whereas lager strains grow at 31.6 to 34.0°C. Thus, it is an easy method for differentiation of strains.

14. Organic acids can be used in the differentiation of strains.
A. True
B. Falseid5fdba54ee58b7″

Answer: A
Clarification: Organic acids can be used in the differentiation of brewing strains. The organic acid profile can be used to discriminate after growth on the assimilatory carbon sources but not after growth on glucose.

To practice tough questions and answers on all areas of Fermentation Technology, .