List of top Bioprocess Engineering and Process Biotechnology Questions on Kinetics of cell growth asked in GATE BT

A microbial culture (following Monod model for growth) has a maximum specific growth rate of 0.1 h\(^{-1}\), Monod constant of 1 mg L\(^{-1}\) and endogenous decay rate of 0.1 day\(^{-1}\). At limiting substrate concentration of 23 g L\(^{-1}\), the net specific growth rate will be ________ day\(^{-1}\). (rounded off to one decimal place)
A microbe that follows Monod growth kinetics on a limiting substrate (maximum specific growth rate of 0.5 h\(^{-1}\) and Monod constant of 0.1 mg L\(^{-1}\)) is cultivated in a continuous reactor for microbial growth (chemostat) with sterile feed. Given that the chemostat volume is 5 L and inlet concentration of limiting substrate is 10 g L\(^{-1}\), the minimum inlet feed flow rate for chemostat washout is L h\(^{-1}\). (rounded off to one decimal place)

The degree of reduction of lactic acid (C3H6O3) is _________.

The specific growth rate of a yeast having a doubling time of 0.693 h (rounded off to nearest integer) is _________ h-1.

Consider the growth of S. cerevisiae under aerobic condition in a bioreactor and the specific growth rate of yeast is 0.5 h$^{-1}$. The overall reaction of the process is \[ 2C_6H_{12}O_6 + 0.2 NH_3 + 10.35 O_2 \to CH_{1.8} O_{0.5} N_{0.2} + 0.2 C_2 H_6 O + 10.6 CO_2 + 10.8 H_2 O \] The heat of combustion values for different compounds are tabulated below with reference to CO$_2$, H$_2$O, O$_2$, and N$_2$ at standard conditions. Heat of Combustion 

CompoundHeat of combustion (kJ mol-1)
C6H12O62802
NH3383
CH1.8O0.5N0.2560
C2H6O1366

The specific rate of heat production (rounded off to the nearest integer) is _________ kJ mol$^{-1}$ h$^{-1}$.

A microorganism is grown in a batch culture using glucose as a carbon source. The apparent growth yield is 0.5 g biomass / g substrate. The initial concentrations of biomass and substrate are 2 g L\(^{-1}\) and 200 g L\(^{-1}\), respectively. Assuming that there is no endogenous metabolism, the maximum biomass concentration that can be achieved is _________ g L\(^{-1}\).
The overall stoichiometry for an aerobic cell growth is \( 3C_6H_{12}O_6 + 2.5 NH_3 + O_2 \rightarrow 1.5 C_a H_b O_c N_d + 3 CO_2 + 5 H_2O \).
What is the elemental composition formula of the biomass?
A batch cultivation of E. coli follows zeroth order Monod kinetics. Growth stops when dissolved oxygen reaches 10% of saturation. The oxygen mass transfer coefficient is \(k_La = 80\ \text{h}^{-1}\). Saturation dissolved oxygen = 0.007 kg m\(^{-3}\). If maximum specific growth rate = 0.2 h\(^{-1}\) and yield coefficient \(Y_{X/O_2} = 1.5\ (\text{kg cells})(\text{kg O}_2)^{-1\), then the final biomass concentration (kg m\(^{-3}\)) is \(\underline{\hspace{1cm}}\).}
The specific growth rate of a mold is 0.15 h\(^{-1}\). If the cell concentration at 30 h is 33 g L\(^{-1}\), the concentration at 24 h (rounded to nearest integer) is \(\underline{\hspace{1cm}}\).
Decimal reduction time of a bacterial strain is 20 min. Specific death rate constant in min\(^{-1}\) (rounded off to two decimal places) is \(\underline{\hspace{1cm}}\).