Bioprocess Engineering Multiple Choice Questions on “Large – Scale Production of Enzymes”.
1. The inactive cells are advantageous for enzyme activity.
A. True
B. False
Answer: A
Explanation: In some cases, it may be more advantageous to use inactive (dead or resting) cells with the desired enzyme activity in immobilized form. This approach eliminates costly enzyme separation and purification steps and is therefore economically more feasible.
2. Which of the following does not produces “Proteases”?
A. Bacillus
B. Rhizopus
C. Mucor
D. Bacillus coagulans
Answer: D
Explanation: A process in which a mutant atypical Bacillus coagulans strain is cultivated in a growth medium free of xylose. The invention relates to glucose isomerase, to methods for the production of this enzyme and to enzymatic isomerization of glucose to fructose with glucose isomerase.
3. Cellulase is used in which type of industry?
A. Food industry
B. Paper industry
C. Biofuel industry
D. Chemical industry
Answer: C
Explanation: Cellulase is used in biofuel industry and its application is class of enzymes that degrade cellulose to glucose monomers.
4. Which of the following is not included in immobilization process?
A. Absorption
B. Adsorption
C. Entrapment
D. Affinity
Answer: A
Explanation: Despite their excellent catalytic capabilities, enzymes and their properties must be improved prior to industrial implementation in many cases. Some aspects of enzymes that must be improved prior to implementation are stability, activity, inhibition by reaction products, and selectivity towards non-natural substrates. This may be accomplished through immobilization of enzymes on a solid material, such as a porous support. Immobilization of enzymes greatly simplifies the recovery process, enhances process control, and reduces operational costs. Many immobilization techniques exist, such as adsorption, covalent binding, affinity, and entrapment.
5. In Upstream processes, process development increases the mRNA hydrolysis and proteolysis?
A. True
B. False
Answer: B
Explanation: Process development is typically performed after genetic modification of the source organism, and involves the modification of the culture medium and growth conditions. In many cases, process development aims to reduce mRNA hydrolysis and proteolysis.
6. Which of the following is not an upstream process?
A. Selection of a suitable enzyme
B. Process development
C. Concentration and primary purification of enzymes
D. Large scale production
Answer: C
Explanation: Downstream processes are those that contribute to separation or purification of enzymes. Depending on the intended use of the enzyme, different levels purity is required. For example, enzymes used for diagnostic purposes must be separated to a higher purity than bulk industrial enzymes to prevent catalytic activity that provides erroneous results.
7. Which of the following purified enzyme is used in pharmaceutical industry?
A. Subtilisin
B. Novozym-435
C. Bromelain
D. Asparaginase
Answer: D
Explanation: Asparaginase enzyme as a desired product is used in pharmaceutical industry as an application for lymphatic cancer therapeutic.
8. Which type of fermentation is used for large scale manufacturing of enzymes?
A. Solid-state fermentation
B. Submerged fermentation
C. Solid-Gas state fermentation
D. Gas-state fermentation
Answer: B
Explanation: Submerged fermentation is a method of manufacturing biomolecules in which enzymes and other reactive compounds are submerged in a liquid such as alcohol, oil or a nutrient broth. The process is used for a variety of purposes, mostly in industrial manufacturing.
9. Which enzyme was first produced industrially?
A. Bacteria enzyme
B. Yeast enzyme
C. Fungal enzyme
D. Streptomyces
Answer: C
Explanation: Microbial enzymes have been utilized for many centuries without knowing them fully. The first enzyme produced industrially was taka-diastase (a fungal amylase) in 1896, in United States. It was used as a pharmaceutical agent to cure digestive disorders.
10. The production of enzyme is mostly carried out by?
A. Batch fermentation
B. Continuous fermentation
C. Fed-batch fermentation
D. Semi-batch fermentation
Answer: A
Explanation: The medium can be sterilized by employing batch or continuous sterilization techniques. The fermentation is started by inoculating the medium. The growth conditions (pH, temperature, O2 supply, nutrient addition) are maintained at optimal levels. The froth formation can be minimised by adding antifoam agents. The production of enzymes is mostly carried out by batch fermentation and to a lesser extent by continuous process.
11. Which is the inducer of enzyme invertase?
A. Starch
B. Sucrose
C. Galactosidases
D. Fatty acids
Answer: B
Explanation: Invertase is an enzyme that catalyzes the hydrolysis (breakdown) of sucrose. The resulting mixture of fructose and glucose is called inverted sugar syrup. For industrial use, invertase is usually derived from yeast. The inducer compounds are expensive and their handling (sterilization, addition at specific time) also is quite difficult.
12. What do you mean by “Nutrient repression”?
A. Inhibition of unwanted enzyme production
B. Production of unwanted enzymes
C. Inhibition of cell nutrients
D. Production of waste
Answer: A
Explanation: The native metabolism of microorganism is so devised that there occurs no production of unnecessary enzymes. In other words, the microorganisms do not synthesize enzymes that are not required by them, since this is a wasteful exercise. The inhibition of unwanted enzyme production is done by nutrient repression. The nutrients may be carbon, nitrogen, phosphate or sulfate suppliers in the growth medium. For large scale production of enzymes, nutrient repression must be overcome.
13. What is the method of screening?
A. To improve the microbial strain
B. To improve the growth of an enzyme
C. To choose appropriate microorganisms for the desired enzyme
D. To determine the optimum conditions for growth of microbes
Answer: C
Explanation: Screening is one of the key optimization parameters to understand the dynamics of the process, allowing for rapid understanding and enhancement of process conditions by analyzing culture metabolic rates and metabolites.
14. System of reaction in which no reactant leaves reaction mixture is termed as ___________
A. Open system
B. Closed system
C. Semi-open system
D. Partially closed system
Answer: B
Explanation: One of the fundamental foundations of bioprocess system design is the use of “closed” systems for production. As a key element of Good Manufacturing Practice (GMP) compliance, closed systems and equipment are utilized to prevent contamination of the product.
15. Which of the following is true for single cell protein?
A. Algae cannot be used in single cell protein
B. It is produced through fermentation
C. It does not contain carbohydrates and vitamins
D. Its utilization increases environmental pollution
Answer: B
Explanation: Single-cell proteins develop when microbes ferment waste materials (including wood, straw, cannery, and food-processing wastes, residues from alcohol production, hydrocarbons, or human and animal excreta). The problem with extracting single-cell proteins from the wastes is the dilution and cost. They are found in very low concentrations, usually less than 5%. Engineers have developed ways to increase the concentrations including centrifugation, flotation, precipitation, coagulation, and filtration, or the use of semi-permeable membranes.