This set of Fermentation Technology Multiple Choice Questions & Answers (MCQs) focuses 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 input
Explanation: 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?
Explanation: 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 McMurrough
Explanation: 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
Explanation: 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?
Explanation: 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?
b) Ionic bonding
Explanation: 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 forces
Explanation: 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 process
Explanation: 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 groups
Explanation: 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
c) Inclusion in fibers
d) Inclusion in microcapsules
Explanation: 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?
d) Covalent bonding
Explanation: 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?
Explanation: 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.
Explanation: 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.
Explanation: 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.
Sanfoundry Global Education & Learning Series – Fermentation Technology.
To practice all areas of Fermentation Technology, here is complete set of 1000+ Multiple Choice Questions and Answers.