In chemostat operating under steady state, a bacterial culture can be grown at dilution rate higher than maximum growth rate by
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Biotechnology Engineering · all questionsBioprocess Engineering and Process Biotechnology
Bioprocess Engineering and Process Biotechnology
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Substrate consumption in lag phase of microbial growth is primarily used for
P. Turnover of the cell material.
Q. Maintenance of intracellular pH.
R. Motility.
S. Increase in cell number.
P. Turnover of the cell material.
Q. Maintenance of intracellular pH.
R. Motility.
S. Increase in cell number.
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Cibacron Blue dye affinity chromatography can be used for affinity purification of
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A culture vessel in which physical, physicochemical and physiological conditions, as well as cell concentration, are kept constant is known as
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Inversion of sucrose by immobilized invertase follows a substrate inhibited kinetics. The reaction rate (v) in mol m-3 h-1 can be expressed as:
where [S] is the sucrose concentration.
The immobilized invertase preparation is used in a CSTR with 100 mol m-3 sucrose concentration in the feed stream. If the reaction velocity passes through a maximum at [S] = 20 mol m-3 the feed flow rate for a reactor volume of 1 m3 to get the maximum productivity from the reactor should be
where [S] is the sucrose concentration.
The immobilized invertase preparation is used in a CSTR with 100 mol m-3 sucrose concentration in the feed stream. If the reaction velocity passes through a maximum at [S] = 20 mol m-3 the feed flow rate for a reactor volume of 1 m3 to get the maximum productivity from the reactor should be
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A bioreactor is scaled up based on equal impeller tip speed. Consider the following parameters for small and large bioreactors:
Assuming geometrical similarity and the bioreactors are operated in turbulent regime, what will be ?
| Parameters | Small bioreactor | Large bioreactor |
| Impeller speed | N1 | N2 |
| Diameter of impeller | D1 | D2 |
| Power consumption | P1 | P2 |
Assuming geometrical similarity and the bioreactors are operated in turbulent regime, what will be ?
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How many kilograms of ethanol is produced from 1 kilogram of glucose in ethanol fermentation?
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Match the bioreactor components in Group I with the most appropriate function given in Group II.
| Group I | Group II |
| P. Marine type impeller | 1. Recirculation of medium |
| Q. Draft tube | 2. Aeration of medium |
| R. Diaphragm valve | 3. Animal cell cultivation |
| S. Sparger | 4. Sterile operation |
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Immobilization of enzymes
P. Increases the specificity of the enzyme for its reactants.
Q. Facilitates reuse of the enzyme in batch reactions.
R. Makes it unsuitable for its use in a continuous reactor system.
S. Decreases the operational cost of the industrial process.
P. Increases the specificity of the enzyme for its reactants.
Q. Facilitates reuse of the enzyme in batch reactions.
R. Makes it unsuitable for its use in a continuous reactor system.
S. Decreases the operational cost of the industrial process.
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A bacterial culture having a specific oxygen uptake rate of 5 mmol O2 (g DCW)-1 hr-1 is being grown aerobically in a fed-batch bioreactor. The maximum value of the volumetric oxygen transfer coefficient is 0.18 s-1 for the stirred tank bioreactor and the critical dissolved oxygen concentration is 20% of the saturation concentration (8 mg mL-1). The maximum density to which the cells can be grown in the fed-batch process without the growth being limited by oxygen transfer, is approximately
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The limiting factor in the production of large quantities of ethanol as biofuel is
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If the fractional recovery at each step of unit operation is 0.8, the recovery after 4 steps will be
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Diauxic pattern of biomass growth is associated with
P. Multiple lag phases.
Q. Sequential utilization of multiple substrates.
R. Simultaneous utilization of multiple substrates.
S. Absence of lag phase.
P. Multiple lag phases.
Q. Sequential utilization of multiple substrates.
R. Simultaneous utilization of multiple substrates.
S. Absence of lag phase.
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Downstream processing of an industrial process yielded a highly purified bioactive protein. This protein was subjected to cleavage by trypsin. Chromatographic separation of products resulted in 4 peptides (P, Q, R, S) with the following amino acid sequences.
P. Phe-Val-Met-Val-Arg
Q. Ala-Ala-Try-Gly-Lys
R. Val-Phe-Met-Ala-Gly-Lys
S. Phe-Gly-Try-Ser-Thr
Chemical cleavage of the same protein with cyanogen bromide and chromatographic separation resulted in three peptides (i, ii, iii) with the following sequences
(i) Ala-Gly-Lys-Phe-Gly-Try-Ser-Thr
(ii) Ala-Ala-Try-Gly-Lys-Phe-Val-Met
(iii) Val-Arg-Val-Phe-Met
The order of the peptides that gives the primary structure of the original protein is
P. Phe-Val-Met-Val-Arg
Q. Ala-Ala-Try-Gly-Lys
R. Val-Phe-Met-Ala-Gly-Lys
S. Phe-Gly-Try-Ser-Thr
Chemical cleavage of the same protein with cyanogen bromide and chromatographic separation resulted in three peptides (i, ii, iii) with the following sequences
(i) Ala-Gly-Lys-Phe-Gly-Try-Ser-Thr
(ii) Ala-Ala-Try-Gly-Lys-Phe-Val-Met
(iii) Val-Arg-Val-Phe-Met
The order of the peptides that gives the primary structure of the original protein is
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Two monomeric His-tagged proteins of identical molecular weight are present in a solution. pIs of these two proteins are 5.6 and 6.8. Which one of the following techniques can be used to separate them?
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Aeration in a bioreactor is provided by
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The specific growth rate (μ) of a microorganism in death phase is
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Immobilization of enzymes using entrapment method requires
P. Photosensitive polyethylene glycol dimethacrylate.
Q. CNBr activation of sepharose.
R. Polyfunctional reagent like hexamethylene diisocyanate.
S. Radiation of polyvinyl alcohol.
P. Photosensitive polyethylene glycol dimethacrylate.
Q. CNBr activation of sepharose.
R. Polyfunctional reagent like hexamethylene diisocyanate.
S. Radiation of polyvinyl alcohol.
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Which of the following techniques is not ideal for immobilizing cell-free enzymes?
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Determine the correctness or otherwise of the following Assertion (A) and Reason (R).
Assertion: Bacterial growth is called synchronous when majority of the cells are in same stage of the bacterial cell cycle.
Reason: Synchronous culture can be obtained by growing bacteria in an enriched medium
Assertion: Bacterial growth is called synchronous when majority of the cells are in same stage of the bacterial cell cycle.
Reason: Synchronous culture can be obtained by growing bacteria in an enriched medium
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