Recent questions in Bioprocess Engineering and Process Biotechnology

Which one of the following can NOT be a limiting substrate if Monod's growth kinetics is applicable?Extracellular carbon sourceExtracellular nitrogen sourceDissolved oxyg...

Which one of the following need NOT be conserved in a biochemical reaction?Total massTotal molesNumber of atoms of each elementTotal energy

In dead-end filtration, rate of filtration isdirectly proportional to the square root of pressure drop across the filter mediuminversely proportional to the pressure drop...

The power required for agitation of non-aerated medium in fermentation is ___________kW.Operating conditions are as follows:Fermentor diameter $= 3$ mNumber of impellers ...

Which one of the following is the most suitable type of impeller for mixing high viscosity (viscosity $ 10^5$ cP) fluids?PropellerHelical ribbonPaddleFlat blade turbine

The empirical formula for biomass of an unknown organism is $CH_{1.8}O_{0.5}N_{0.2}$. To grow this organism, ethanol $(C_2H_5OH)$ and ammonia are used as carbon and nitro...

$\textit{Saccharomyces cerevisiae}$ is cultured in a chemostat (continuous fermentation) at a dilution rate of $0.5 \: h^{-1}$. The feed substrate concentration is $10 \:...

Decimal reduction time of bacterial spores is $23$ min at $121 ^\circ C$ and the death kinetics follow first order. One liter medium containing $10^5$ spores per $mL$ was...

A bioreactor is scaled up based on equal impeller tip speed. Consider the following parameters for small and large bioreactors: $$\begin{array}{|l|l|l|l|} \hline \textbf...

An enzyme converts substrate $A$ to product $B$. At a given liquid feed stream of o rate $25$ L.min$^{-1}$ and feed substrate concentration of $2$ mol.L$^{-1}$, the volum...

An enzyme is immobilized on the surface of a non-porous spherical particle of $2$ mm diameter. The immobilized enzyme is suspended in a solution having bulk substrate con...

A $5$ liter chemostat is fed fresh medium at $0.2$ liters/minute having a substrate concentration of $25$ grams/liter. At steady state, the outgoing stream has substrate ...

For an $\textit{E.coli}$ culture in the exponential phase of growth, optical density (OD) at $540$ nm is $0.3$ at $2$ hours and $0.6$ at $4$ hours. Assuming that the meas...

A zero-order liquid phase reaction $A \xrightarrow{k} B$ is being carried out in a batch reactor with $k=10^{-3}$ mol/min. If the starting concentration of $A$ is $0.1$ m...

During anaerobic growth, an organism converts glucose $(P)$ into biomass $(Q)$, ethanol $(R)$, acetaldehyde $(S)$, and glycerol $(T)$. Every mole of carbon present in glu...

Oxygen transfer was measured in a stirred tank bioreactor using dynamic method. The dissolved oxygen tension was found to be $80 \%$ air saturation under steady state con...

The diameters of a large and a small vessel are $1.62$ m and $16.2$ cm. ,respectively. The vessels are geometrically similar and operated under similar volumetric agitate...

In a fed-batch culture, $200 \text{ g . L}^{-1}$ glucose solution is added at a flow rate of $50 \text{ L . h}^{-1}$ . The initial culture volume (at quasi steady state) ...

Biomass is being produced in a continuous stirred tank bioreactor of $750$ L capacity. The sterile feed containing $8 \: g \cdot L^{-1}$ glucose as substrate was fed at a...

The unit for specific substrate consumption rate in a growing culture is$\frac{g}{L-h}$$\frac{g}{h}$$\frac{g}{g-h}$$\frac{gmoles}{L-h}$

Which of the following is employed for the repeated use of enzymes in bioprocesses?polymerizationimmobilizationligationisomerization

Since mammalian cells are sensitive to shear, scale-up of a mammalian cell process must consider, among other parameters, the following $\text{(given N=rotations/time, D=...

The degree of reduction of ethanol is_______

A T- ask is seeded with $10^5$ anchorage-dependent cells. The available area of the T- ask is $25\: cm^2$ and the volume of the medium is $25\: ml$. Assume that the cells...

Consider a continuous culture provided with a sterile feed containing $10$ mM glucose. The steady state cell density and substrate concentration at three different diluti...

What is the holding period (min) at a $K$ value of $\text{3.36min}^{-1}?$$10.6$$9.5$$8.4$$7.2$

During sterilization of a fermentation medium in a given bioreactor $\nabla_{heaing}=12.56, \nabla_{cooling}= 7.48$ and the total value of $\nabla$ required for whole ste...

The maximum cell concentration $(\text{g l}^{-1})$ expected in a bioreactor with initial cell concentration of $\text{1.75 g l}^{-1}$ and an initial glucose concentration...

Determine the correctness or otherwise of the following $\text{Assertion (a)}$ and $\text{Reason (r)}.$$\text{Assertion:}$ Immobilization of plant cells can enhance secon...

In a batch culture, the specific rate of substrate utilization is $\text{0.25 g (g cell mass)}$$^{-1} h^{-1}$ and specific rate of product formation is $\text{0.215 g (g ...

A batch bioreactor is to be scaled up from $\text{10 to 10,000}$ liters. The diameter of the large bioreactor is $10$ times that of the small bioreactor. The agitator spe...

A chemostat is operated at a dilution rate of $0.6\; h^{-1}$. At steady state, the biomass concentration in the exit stream was found to be $30\; gl^{-1}$The biomass prod...

$\beta$-Galactosidase bound to DEAE-cellulose is used to hydrolyze lactose to glucose and galactose in a plug flow bioreactor with a packed bed of volume $100$ liters and...

$\beta$-Galactosidase bound to DEAE-cellulose is used to hydrolyze lactose to glucose and galactose in a plug flow bioreactor with a packed bed of volume $100$ liters and...

Determine the correctness or otherwise of the following $Assertion$ (a) and $Reason$ (r).$Assertion:$ Cell mass yield of a methylotrophic yeast is more on methanol compar...

Match the downstream processes in $\text{Group I}$ with the products in $\text{Group II}$.$\begin{array}{|C|l|C|l|} \hline& \textbf{Group I} & {} & \textbf{Group II} \\\h...