12.
Thermal death of microorganisms in the liquid medium follows first order kinetics. If the initial cell concentration in the fermentation medium is 108 cells mL-1 and the final acceptable contamination level is 10-3 cells, for how long should 1 m3 medium be treated at temperature of 120°C (thermal deactivation rate constant = 0.23 min-1) to achieve acceptable load?

13.
Match separation methods in Group I with associated properties in Group II.
Group I Group II
P. Centrifugation 1. Density
Q. Dialysis 2. Diffusivity
R. Solvent extraction 3. Size
S. Ultrafiltration 4. Solubility

14.
In dead-end filtration, rate of filtration is

15.
Which one of the following statements is correct about proportional controllers?

16.
A batch culture fermentation was being conducted with Streptomyces rimosus, Analysis of samples collected indicated doubling of cell number per unit time. Your interference would be that the culture is in the

17.
In an exponentially growing batch culture of Saccharomyces cerevisiae, the cell density is 20 g L-1 (DCW), the specific growth rate (μ) is 0.4 h-1 and substrate uptake rate (v) is 16 g L-1 h-1. The cell yield coefficient \[{Y_{\frac{X}{S}}}\] will be

19.
Evaluate the Michaelis constant for the following lipase catalyzed transesterification reaction for the production of biodiesel.
$${\text{Vegetale oil}} + {\text{Lipase}} + \mathop \rightleftharpoons \limits_{{{\text{k}}1}}^{{{\text{k}}{ - 1}}} {\text{ Oil-lipase complex }}\mathop \to \limits^{{{\text{k}}_1}} {\text{Biodiesel}} + {\text{Glycerol}}$$
where k1 = 3 × 108 M−1 s−1; k−1 = 4 × 104 s−1 and k2 = 2 × 103 s−1