#Question id: 14295
#SCPH05 I Biotechnology
Pseudomonas methylotrophus is used to produce single-cell
protein from methanol in a 1000 m3 pressure-cycle airlift fermenter.
The biomass yield from substrate is 0.41 g g- 1, KS is
0.7 mg l- 1, and the maximum specific growth rate is 0.44 h- 1.
The medium contains 4% (w/v) methanol. A substrate conversion of 98% is
desirable. The reactor may be operated either in batch or continuous mode. If
operated in batch, an inoculum of 0.01% (w/v) is used and the downtime between
batches is 20 h. If operated continuously, a downtime of 25 d is expected per
year. Neglecting maintenance requirements, compare the annual biomass
production from batch and continuous reactors?
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#Question id: 14296
#SCPH05 I Biotechnology
A two-stage chemostat system is used for production of
secondary metabolite. The volume of each reactor is 0.5 m3; the flow
rate of feed is 50 l h- 1. Mycelial growth occurs in the first
reactor; the second reactor is used for product synthesis. The concentration of
substrate in the feed is 10 gl-1. Kinetic and yield parameters for
the organism are:
Assume that product synthesis is negligible in the first
reactor and growth is negligible in the second reactor. Determine cell
concentrations entering the second reactor.
#Question id: 14297
#SCPH05 I Biotechnology
A two-stage chemostat system is used for production of
secondary metabolite. The volume of each reactor is 0.5 m3; the flow
rate of feed is 50 l h- 1. Mycelial growth occurs in the first
reactor; the second reactor is used for product synthesis. The concentration of
substrate in the feed is 10 gl-1. Kinetic and yield parameters for
the organism are:
Assume that product synthesis is negligible in the first
reactor and growth is negligible in the second reactor. Determine substrate
concentrations entering the second reactor.
#Question id: 14298
#SCPH05 I Biotechnology
A two-stage chemostat system is used for production of
secondary metabolite. The volume of each reactor is 0.5 m3; the flow
rate of feed is 50 l h- 1. Mycelial growth occurs in the first
reactor; the second reactor is used for product synthesis. The concentration of
substrate in the feed is 10 gl-1. Kinetic and yield parameters for
the organism are:
Assume that product synthesis is negligible in the first
reactor and growth is negligible in the second reactor. What is the overall
substrate conversion?
#Question id: 14299
#SCPH05 I Biotechnology
Assume that product synthesis is negligible in the first
reactor and growth is negligible in the second reactor. What is the final
concentration of product?
#Question id: 14300
#SCPH05 I Biotechnology
A 15-m 3 chemostat is operated with dilution rate 0.1 h-1. A continuous steriliser with steam injection and flash cooling delivers sterilized medium to the fermenter. Medium in the holding section of the steriliser is maintained at 130⁰C The concentration of contaminants in the raw medium is 105 ml-l; an acceptable contamination risk is one organism every 3 months. The Arrhenius constant and activation energy for thermal death are estimated to be 7.5 × 1039 h-1 and 288.5 kJ gmol- 1, respectively. The steriliser pipe inner diameter is 12 cm. At 130⁰C the liquid density is 1000 kg m- 3 and the viscosity is 4 kg m- 1 h- 1. Assuming perfect plug flow, determine the length of the holding section. __________________