Recent questions tagged bioreaction-engineering

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 is the unit of heat transfer coefficient?$W\:m^{2}K^{-1}$$W\:m^{-2}K$$W\:m^{-2}K^{-1}$$W\:m^{2}K$

A biological process is involved in the __________ treatment of industrial effluent.primarysecondarytertiaryquaternary

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...

Consider the equation$V=\dfrac{aS}{b+S+\dfrac{S^2}{c}}$Given $a = 4$, $b = 1$ and $c = 9$, the positive value of $S$ at which $V$ is maximum, will be _________

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 ...

Growth of a microbe in a test tube is modeled as $\dfrac{dX}{dt} = rX \bigg (1 – \dfrac{X}{K}\bigg )$, where, $X$ is the biomass, $r$ is the growth rate, and $K$ is the c...

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...

Which one of the following relations holds true for the specific growth rate $(\mu)$ of a microorganism in the death phase?$\mu=0$$\mu<0$$\mu=\mu_{\text{max}}$$0<\mu<\mu_...

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...

$\textit{Saccharomyces cerevisiae}$ produces ethanol by fermentation. The theoretical yield of ethanol from $2.5$ g of glucose is _________ g.

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}$

The most plausible explanation for a sudden increase of the respiratory quotient $(RQ)$ of a microbial culture is thatcells are dyingyield of biomass is increasingthe fer...

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=...

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...

Lysine is being produced in a lab-scale reactor by a threonine auxotroph. After 2 weeks of operation it was observed that the concentration of lysine in the reactor was g...

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...