Biochemical Engineering

Question 1

What is the basis of the sterilization conditions at 15 psi and 121 °C for 15 minutes?

Answer 1

bacterial spores

Question 2

The del factor increases when the final cell number ____.

Answer 2

decreases

Question 3

An enzyme promotes a chemical reaction by

Answer 3

lowering Activation energy

bringing substrates together in an optimal orientation,

Question 4

Biochemical reaction involving single substrate.

Answer 4

Michaelis Menten

Question 5

It is the stage at which majority of the cells are killed during the sterilization process.

Answer 5

Holding Section/Stage

Question 6

At a non-steady-state operation of bioreactors, where the dilution rate is greater than the
specific growth rate, what will be the behavior of the system towards steady-state?

Answer 6

The specific growth rate will increase to the value of dilution rate

Question 7

Given that μ = 200 and μmax = 200, what can be said about Ks and S?

Answer 7

Ks < S
Ks is much lower than S

Question 8

A certain microorganism (μmax = 0.8 hr-1) is exposed to 2.0 g/L of substrate. Find the specific growth rate (hr-1). Ks = 150 mg./L

Answer 8

0.744/hr

Question 9

Calculate the dilution rate (hr-1) of a 1-m diameter chemostat with a liquid height of 4 m and a flow rate of 800 L/hr.

Answer 9

0.255/hr

Question 10

What is the del factor if an initial cell count of 3x10^8/mL is reduced to 5x10^2/mL?

Answer 10

13.305

Question 11

What is the del factor if the sterility level is 3.86x10^-5?

Answer 11

11.51

Question 12

A 2000-kg mixture containing 23% galactose, 37% glucose, 16% fructose, and 24% non-fermentable residues is fermented by a yeast to produce ethanol. How much ethanol is produced if 85% of the substrate is converted to ethanol and 15% is converted to
biomass?

Answer 12

660.36