#Question id: 14506
#Section 1: Engineering Mathematics
#Question id: 14247
#Section 5: Bioprocess Engineering and Process Biotechnology
A steam steriliser is used to sterilise liquid medium for fermentation.
The initial concentration of contaminating organisms is 108 per
litre. For design purposes, the final acceptable level of contamination is
usually taken to be 10-3cells; this corresponds to a risk that one
batch in a thousand will remain contaminated even after the sterilisation
process is complete. For how long should 1 m3 medium be treated if
the temperature is 121⁰C ________________.
#Question id: 4832
#Section 3: Genetics, Cellular and Molecular Biology
Percentage of crossing over is more when
#Question id: 19483
#Section 4: Fundamentals of Biological Engineering
#Question id: 14201
#Section 5: Bioprocess Engineering and Process Biotechnology
A fluidized-bed, immobilized-cell bioreactor is used for the
conversion of glucose to ethanol by Z. mobilis cells immobilized in
k-carrageenan gel beads. The dimensions of the bed are 10 cm (diameter) by 200
cm. Since the reactor is fed from the bottom of the column and because of CO2
gas evolution, substrate and cell concentrations decrease with the height of
the column. The average cell concentration at the bottom of the column is X0
= 45 g/l, and the average cell concentration decreases with the column
height according to the following equation:
where Z is the column height (cm). The specific rate of
substrate consumption is qS = 2 g S/g cells . h. The feed flow rate
and glucose concentration in the feed are 5 l/h and 160 g glucose/l,
respectively.
Determine the ethanol productivity (g/l . h) if YP/S = 0.48
g ethanol/g glucose.
_______________