A batch cultivation of $\textit{E. coli}$ follows zeroth order Monod’s growth kinetics. The cell growth is terminated when the residual dissolved oxygen concentration attains $10\%$ of its saturation value and oxygen mass transfer coefficient $(k_La)$ reaches its maximum value $(80h^{-1})$. The saturation value of dissolved oxygen concentration is $0.007 \textit{ kg m}^{-3}$. If the maximum specific growth rate and yield coefficient $(Y_{X/O_2})$ are $0.2 \: h^{-1}$ and $1.5 \textit{ (kg cells)(kg O$_2$)}^{-1}$, respectively, then the final cell concentration in $\textit{kg m}^{-3}$ (rounded off to two decimal places) at the end of the batch cultivation is __________
