#Question id: 14300
#Section 5: Bioprocess Engineering and Process 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. __________________
#Question id: 14301
#Section 5: Bioprocess Engineering and Process Biotechnology
Pseudomonas sp. has a mass doubling time of
2.4 h when grown on acetate. The saturation constant using this substrate is
1.3 g/l (which is unusually high), and cell yield on acetate is 0.46 g cell/g
acetate. If we operate a chemostat on a feed stream containing 38 g/l acetate,
find the Cell concentration when the dilution rate is one-half of the maximum?
#Question id: 14302
#Section 5: Bioprocess Engineering and Process Biotechnology
Pseudomonas sp. has a mass doubling time of 2.4 h when grown
on acetate. The saturation constant using this substrate is 1.3 g/l (which is
unusually high), and cell yield on acetate is 0.46 g cell/g acetate. If we
operate a chemostat on a feed stream containing 38 g/l acetate, find the
Substrate concentration when the dilution rate is 0.8Dmax?
__________________
#Question id: 14303
#Section 5: Bioprocess Engineering and Process Biotechnology
Pseudomonas sp. has a mass doubling time of 2.4 h when grown
on acetate. The saturation constant using this substrate is 1.3 g/l (which is
unusually high), and cell yield on acetate is 0.46 g cell/g acetate. If we
operate a chemostat on a feed stream containing 38 g/l acetate, find the Maximum
dilution rate?
_________
#Question id: 14304
#Section 5: Bioprocess Engineering and Process Biotechnology
Pseudomonas sp. has a mass doubling time of 2.4 h when grown
on acetate. The saturation constant using this substrate is 1.3 g/l (which is
unusually high), and cell yield on acetate is 0.46 g cell/g acetate. If we
operate a chemostat on a feed stream containing 38 g/l acetate, find the Cell
productivity at 0.8 Dmax?
_____________
#Question id: 14305
#Section 5: Bioprocess Engineering and Process Biotechnology
Ethanol is to be used as a substrate for single-cell protein
production in a chemostat. The available equipment can achieve an oxygen
transfer rate of 10 g O2/l of liquid per hour. Assume the kinetics
of cell growth on ethanol is of the Monod type, with µm = 0.5 h–1, Ks
= 30 mg/l, YX/S = 0.5 cells/g ethanol, and YO2/S = 2 g O2/g EtOH. We wish to
operate the chemostat with an ethanol concentration in the feed of 22 g/L. We
also wish to maximize the biomass productivity and minimize the loss of unused
ethanol in the effluent. Determine the required dilution rate