etermine the $$max from the NaOH consumption plotThe $pH$ was controlled by using $6$MNaOH. As can be seen from figure $1,$ it remained consistently around $5\mathrm{.}5$ and $6$ during the cultivation. The consumption of NaOH was measured during the cultivation of both $15l$ and $200l$ reactors. Measures of NaOH consumption during $15l$ cultivation are shown below as figure $2.$

Figure $2.$ NaOH consumption $($ml$)$ in $15l$ bioreactor over time