Match the following:

A. RNA analysis               i. Sexing or cell mutation sites               a. Expressed Sequence tag

B. Forensic science           ii. mRNA analysis                                     b.  Analysis of DNA from blood

C. Gene discovery              iii. DNA profiling                                       c. Active latent viral infections

D. Single-cell analysis     iv.  RT–PCR                                             d. Sex determination of unborn

#Question id: 14241

#Section 5: Bioprocess Engineering and Process Biotechnology

Yeast cells are to be separated from a fermentation broth. Assume that the cells are spherical with diameter 5 µm and density 1.06 g cm^-3. The viscosity of the culture broth is 1.36 x 10^-3 N s m^-2. At the temperature of separation, the density of the suspending fluid is 0.997 g cm^-3. 500 litres broth must be treated every hour. Specify Σ for a suitably-sized disc-stack centrifuge

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#Question id: 14242

#Section 5: Bioprocess Engineering and Process Biotechnology

Small food particles with diameter 10^-2 mm and density 1.03 g cm^-3 are suspended in liquid of density 1.00 g cm^-3. The viscosity of the liquid is 1.25 mPa s. A tubular-bowl centrifuge of length 70 cm and radius 11.5 cm is used to separate the particles. If the centrifuge is operated at 10 000 rpm, estimate the feed flow rate at which the food particles are just removed from the suspension. ____________________

#Question id: 14243

#Section 5: Bioprocess Engineering and Process Biotechnology

A tubular-bowl centrifuge is used to concentrate a suspension of genetically-engineered yeast containing a new recombinant protein. At a speed of 12 000 rpm, the centrifuge treats 3 l broth min^-1 with satisfactory results. It is proposed to use the same centrifuge to separate cell debris from homogenate produced by mechanical disruption of the yeast. If the average size of the debris is one-third that of the yeast and the viscosity of the homogenate is five times greater than the cell suspension, what flow rate can be handled if the centrifuge is operated at the same speed? _____________________

#Question id: 14244

#Section 5: Bioprocess Engineering and Process Biotechnology

Ethanol is produced by anaerobic fermentation of glucose by Saccharomyces cerevisiae. For the particular strain of S. cerevisiae employed, the maintenance coefficient is 0.18 kg kg^{- 1} h^{- 1}, Yxs is 0.11 kg kg^-1, Y_PX is 3.9 kg kg^-1 and µ_max is 0.4 h^-1.  It is decided to investigate the possibility of using Zymomonas mobilis bacteria instead of yeast for making ethanol. Z. mobilis is known to produce ethanol under anaerobic conditions using a different metabolic pathway to that employed by yeast. Typical values of Yxs are lower than for yeast at about 0.06 kg kg^-1; on the other hand, the maintenance coefficient is higher at 2.2 kg kg ^-1 h ^-1. Ypx for Z. mobilis is 7.7 kg kg^-l; µ_max is 0.3 h- 1.  From stoichiometry, what is the maximum theoretical yield of ethanol from glucose                 

#Question id: 14246

#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 80⁰C ________________.10^6

 To be safe, assume that the contaminants present are spores of Bacillus stearothermophilus, one of the most heat-resistant microorganisms known. For these spores the activation energy for thermal death is 283 kJ gmo1^-1 and the Arrhenius constant is 10^36.2 s^-1