The Intermig impeller is an axial flow impeller which can be used for the cultur

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Question
The Intermig impeller is
Options
A. an axial flow impeller which can be used for the culture of aerobic organisms
B. directed upwards rather than towards the base of the reactor
C. a fork shaped extensions to the impeller facilitate bubble break up
D. All of the above

Correct Answer

All of the above

3. The power required by an impeller in a gas sparged system compare to the power required by impeller operating at same speed in a gas free liquid is usually
Options
A. lesser
B. higher
C. same
D. may be lesser or higher depending upon the geometry

4. The maximum solubility of the alkane in the medium is 5 ppm. If the actual dissolved concentration of the alkane in the medium is 1 ppm. what conclusion may be drawn?
Options
A. The growth rate is limited by the rate of mass transfer of the alkane into the fermentation medium
B. The growth rate is limited by the intrinsic kinetic properties of the cells and not by mass transfer
C. The growth rate is neither mass transfer nor kinetically limited
D. No conclusion on the growth rate can be withdrawn

6. To increase the oxygen transfer rate in a shake flask culture system, which of the following (s) is/are followed?
Options
A. Liquid volume in the flask is reduced
B. Stirrer speed is increased
C. Baffled flasks are used
D. All of the above

8. Detergent like substances produced by microorganisms during a fermentation will lead to
Options
A. decrease the surface tension of the liquid
B. accumulate at the gas liquid interface
C. decrease the rate of bubble coalescence
D. all of the above

10. Pure oxygen, if used instead of air will increase oxygen transfer rates because
Options
A. the saturation concentration of oxygen is higher
B. the bubble size is smaller
C. the oxygen transfer coefficient is larger
D. the partial pressure of oxygen in the gas phase is lower

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