Over expression of primary metabolites are often achieved by

1. Frequency of RNA polymerase binding to the promoter region

2. Copy number increase of structural genes for these enzymes by genetic engineering

3. Chemically derived protein

Which combination below represent correct option?

#Question id: 14269

#SCPH05 I Biotechnology

An activated-sludge waste treatment system is required to reduce the amount of BOD₅ from 1000 mg/l to 20 mg/l at the exit. The sedimentation unit concentrates biomass by a factor of 3. Kinetic parameters are µ_m = 0.2 h-1 , K_s = 80 mg/l, k_d = 0.01 h-1 , and Y ^M _X/S = 0.5 g MLVSS/g BOD₅. The flow of waste water is 10000 l/h and the size of the treatme nt basin is 50,000 l. What value of the recycle ratio must be used?

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#Question id: 14271

#SCPH05 I Biotechnology

Penicillin is produced by P. chrysogenum in a fed-batch culture with the intermittent addition of glucose solution to the culture medium. The initial culture volume at quasi-steady state is V0 = 500 l, and glucose-containing nutrient solution is added with a flow rate of F = 50 l/h. Glucose concentration in the feed solution and initial cell concentration are S0 = 300 g/l and X0 = 20 g/l, respectively. The kinetic and yield coefficients of the organism are mm = 0.2 h-1 , KS = 0.5 g/l, and YX/S = 0.3 g dw/g glucose. Determine the concentration of cells at quasi-steady state when t = 10 h.

#Question id: 14272

#SCPH05 I Biotechnology

Penicillin is produced by P. chrysogenum in a fed-batch culture with the intermittent addition of glucose solution to the culture medium. The initial culture volume at quasi-steady state is V0 = 500 l, and glucose-containing nutrient solution is added with a flow rate of F = 50 l/h. Glucose concentration in the feed solution and initial cell concentration are S0 = 300 g/l and X0 = 20 g/l, respectively. The kinetic and yield coefficients of the organism are mm = 0.2 h-1 , KS = 0.5 g/l, and YX/S = 0.3 g dw/g glucose. If qP = 0.05 g product/g cells h and P₀ = 0.1 g/l, determine the product concentration in the vessel at t = 10 h

#Question id: 14273

#SCPH05 I Biotechnology

Nicotiana tabacum cells are cultured to high density for production of polysaccharide gum. The reactor used is a stirred tank, containing initially 100 litres medium. The maximum specific growth rate of the culture is 0.18 d^-1 and the yield of biomass from substrate is 0.5 g g^-l. The concentration of growth-limiting substrate in the medium is 3% (w/v). The reactor is inoculated with 1.5 g l^{- 1} cells and operated in batch until the substrate is virtually exhausted; medium flow is then started at a rate of 4 l d^-1. Fed-batch operation occurs under quasi-steady-state conditions. Estimate the batch culture time.                                  ____________________

#Question id: 14274

#SCPH05 I Biotechnology

Nicotiana tabacum cells are cultured to high density for production of polysaccharide gum. The reactor used is a stirred tank, containing initially 100 litres medium. The maximum specific growth rate of the culture is 0.18 d^-1 and the yield of biomass from substrate is 0.5 g g^-l. The concentration of growth-limiting substrate in the medium is 3% (w/v). The reactor is inoculated with 1.5 g l^{- 1} cells and operated in batch until the substrate is virtually exhausted; medium flow is then started at a rate of 4 l d^-1. Fed-batch operation occurs under quasi-steady-state conditions. Estimate final biomass concentration?

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